sourcebook in environmental education for secondary school teachers

Sourcebook .A

in Environmentul Education for Secondary School Teachers

Editors :

R.C. Sharma

Merle C. Tan

Unesco Principal Regional Office for Asia and the Pacific Bangkok, 1990

-- -._-- --

@ UNESCO 1990

Published by the Unesco Principal Regional Office for Asia and the Pacific

P.O. Box 967, Prakanong Post Office Bangkok 10110, Thailand

Printed in Thailand

Tlle desig~latiorts employed altd the presentation of material throughout the publication do not imply the expressiorr of any opiniorl whatsoever 011 the part of Utesco concerning the legal status of any country, territory, city or area or of its authon’ties, or cortcemiq its froritiers or boundaries.

BKP/91/M/62-3000

PREFACE

The human intervention in the natural process during the past few decades has created environmental problems of serious concern. Acid rain is destroying forests thousands of miles away from coal-fired power plants. The ozone in the upper atmosphere that protects all life from the sun’s harmful ultraviolet rays is being depleted by chemicals released from air conditioners, refrigerators, aerosol sprays and other products. The extensive destruction of forests by illegal logging/cutting and clearing for shifting cultivation, increasing agricultural land areas, firewood and charcoal, and forest-product trade is causing problems of soil erosion, dessertification, climatic changes, floods and increased concentration of carbon dioxide in the atmosphere leading to its warming through the so called”greenhouse effect”. The more frequent droughts, heat waves and floods during the past few years is an indication of the effects of deforestation and pollution.

Increased environment consciousness in the ASEAN region brought about by destruction and disregard of biological support systems and environment has led to changes in the school curriculum with respect to the incorporation of environmental education. This has given rise to the problem of shortage of teachers and supervisors who are well trained particularly in the environmental dimension of science. In order to meet this emerging need the project on Training Programme on Environmental Education for Science Teachers and Supervisors in the ASEAN Region was launched in August 1988 with the funding support of UNDP.

The project was implemented by the Ministries of Education of ASEAN member countries, except Singapore, under the ASEAN COST and executed by the Unesco Principal Regional Office for Asia and the Pacific, Bangkok in association with the UNEP Regional Office, Bangkok.

This Source Book on Environmental Education is the outcome of the Regional Training Course which was organized by Unesco PROAP at the Institute of Science and Mathematics Education Development (ISMED), University of the Philippines, Quezon City, Philippines from 24 July to 11 August 1989. It consists of two parts. Part One contains twelve chapters covering a wide range of topics on the knowledge base of environmental education. Part Two also contains twelve chapters on the pedagogical aspects of environmental education. The sourcebook also includes exemplar lesson plans, sample instruments for assesing students’ achievements and evaluating training programmes, and worksheets for organizing field investigations.

I would like to express gratitude to the authors whose papers have been included in this Sourcebook as well as to the participants of the Regional Training Course in Environmental Education for their contributions particularly in developing lesson plans, sample evaluation instruments, reports of field visits, curriculum outline, etc. I would also like to thank Dr. R. C. Sharma, Regional Adviser for In-School Population Education and Officer-in-Charge for Environmental Education and Dr. Merle C. Tan of the Institute of Science and Mathematics Education Development, University of the Philippines for their hard work in compiling and editing the Sourcebook.

I sincerely hope that the Sourcebook will be a useful reference material for curriculum developers, teacher educators, trainers and secondary school teachers in implementing environmental education programmes.

k&S Director, Unesco PROAP

Table of Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Part I - The Knowledge Base

Chapter 1.

Chapter 2.

Chapter 3.

Chapter 4.

Chapter 5.

Chapter 6.

Chapter 7.

Chapter 8.

Chapter 9.

Chapter 10.

Chapter 11.

Chapter 12.

The Concept of Environmental Education by Dr. Ruben B. Aspiras. . . . . . . . . . . . . . .

Structure and Function of the Ecosystem by Dr. Reynaldo A. Tabbada. . . . . . . . . . . . .

Energy FIow in the Atmosphere byDr. JorgedelasAlas. . . . . . . . . . . . . . .

Energy Flow and Nutrients Cycle in the Biosphere by Dr. Reynaldo A. Tabbada. . . . . . . . . . . . .

Population Dynamics in an Ecosystem byDr. RC. Sharma. . . . . . . . . . . . . . . .

Impact of Human Activities on the Environment: Global Issues byit4r. EC Onogawa. . . . . . . . . . . . . . . .

Pollution - Its Effects on Man and the Ecosystem byMr. K Onogawa. . . . . . . . . . . . . . . .

Degradation of the Forest Ecosystems: Its Socio-Cultural and Economic Implications by Dr. Sever0 R. Saplaco. . . . . . _ . . . . . . .

Ecological Impacts on Aquatic Ecosystems by Dr. Armando A. Andaya. . . . . . . . . . . . .

The Effects of Energy and Mineral Extraction by Dr. Teodoro M. Santos. . . . . . . . . . . . . .

Environmental Management in the Context of Sustainable Development byDr. Beta P. Balagot. . . . . . . . . . . . . . .

Environmental Management and Impact Assessment byDr. Beta P. Balagot. . . . . . . . . . . . . _ .

. 7

. 13

. 33

. 41

. 71

. 83

. 97

111

115

119

141

149

I .

-___--_. ___” __-_-___ - ._____- - . - - . . - . ..___ - - . . - . . ~ . - __.. - - - . . - . . . ^

Part II - The Pedagogical Aspects

Chapter 13.

Chapter 14.

Chapter 15.

Chapter 16.

Chapter 17.

Chapter 18.

Chapter 19.

Chapter 20.

Chapter 21.

Chapter 22.

Chapter 23.

Chapter 24.

Appendices

I.

II.

III.

IV.

Index

Developments in Environmental Education byDr.R.C.Shatma. . . . . . . . . . . . . . . . 163

Framework for Environmental Education byDr. Leticia P. Cortes. . . . . . . . . . . . . . . 171

Planning and Developing Curricula on Environmental Education byDr. MerleC. Tan. . . . . . . . . . . . . . . . 183

The Role of Values Education in Environmental Education byDr. MindaC.Sutaria. . . . . . . . . . . . . . . 189

Values Clarification in Environmental Education byDr. Lilia M. Rabago. . . . . . . . . . . . . . . 193

Ethics and Social Responsibility Towards the Environment: Guidelines for Science Teachers by Dr. Serafwz D. Talisayon. . . . . . . . . . . . . 199

Community-based Environmental Education by Dr. Vivien M. Talkayon. . . . . . . . . . . . . . 211

Inquiry and Problem Solving by Dr. Lourdes R. Carale. . . . . . . . . . . . . . 217

Games and Simulation in Environmental Education byDr. MerleC. Tan. . . . . . . . . . . . . . . . 221

Lesson Planning and Development of Teaching Aids byDr.Adelaida L. Bago. . . . . . . . . . . . . . 227

Supervision and Monitoring of Environmental Education Classes by Dr. Milagros Ibe. . . . . . . . . . . . . . . . 237

Research in Environmental Education: Its Implications for Classroom Teaching and Teacher Training byDr. MerleC. Tan. . . . . . . . . . . . . . . . 251

Exemplar Lesson Plans . . . . . . . . . . . . . . 257

Sample Instruments for Assessing Student’s Achievement . . 265

Sample Instruments for Evaluating Training Programmes . . 273

Worksheets for Organizing Field Investigations . . . . . 287

List of Figures

Part I The Knowledge Base

Figure 2.1

Figure 2.2

Figure 2.3

Figure 2.4

Figure 4.1

Figure 4.2

Figure 4.3

Figure 4.4

Figure 4.5

Figure 4.6

Figure 4.7

Figure 4.8

Figure 4.9

Figure 4.10

Figure 4.11

Figur 4.12

The closed and open types of systems .......... 15

Biotic and chemical components of the ecosystem ...... 16

The three models of succession in the ecosystem ...... 24

The cyclic type of community change and its four phases ................ 25

Energy exploitation by living organisms in the biosphere ................. 43

The solar energy balance of Earth ........... 45

Schematic models of the grazing food chain and the detrial foodchain ............. 50

Major biotic components of a food web in an east African grassland ............. 52

The three models of pyramid of numbers ......... 53

A pyramid of biomass in an abandoned field ........ 54

A pyramid of energy for a freshwater ecosystem ...... 54

A hudraulic analogy of the pattern of energy flow in the biosphere ........... 55

Schematic flow of energy in the biosphere ........ 56

A schematic model to show cyclic flow of nutrients in the biosphere driven by one way flow of energy .... 58

A schematic model of nutrient flow showing the individual compartments and the direction of flow .............. 59

A generalized schematic diagram of the different compartments and the flow of nutrients in the global nutrient cycles ............. 60

Figure 4.13

Figure 4.14

Figure 4.15

Figure 4.16

Figure 4.17

Figure 5.1

Figure 5.2

Figure 5.3

Figure 5.4

Figure 5.5

Figure 5.6

Figur 5.7

Figure 6.1

Figure 6.2

Figure 6.3

Figure 6.4

Figure 6.5

Figure 6.6

Figure 7.1

Figure 10.1

Figure 10.2

A generalized schematic diagram of a sedimentary or local cycle ............ 61

The major compartments and processes involved in the global carbon cycle ............. 63

The compartments and processes involved in the global nitrogen cycle ............. 64

The compartments and processes involved in the phosphorus cycle .............. 66

The compartments and processes involved in the sulphur cycle ............... 67

Theoretical relationship between biotic potential, environmental resistance and logistic curve ....... 72

The relationship between the biotic potential and the capacity of the environment ......... 73

The food web .................. 75

World population through history ........... 76

Percentage distribution of population by region in 1950,1980,2025 ................ 77

Relations between increasing population and environmental pollution ............ 79

World model standard run ............. 81

Solar radiation wavelengths ............. 84

Destruction of ozone ............... 86

Trend in C02concentration from 1958 to 1984 ...... 89

Other Greenhouse gases .............. 90

pHvalues of rainfall in Europe and North America ..... 93

Benefits of forests ................. 95

The regional seas ................ 108

Diagram showing the complete opencast mining cycle ... 129

Environmental disturbances from coal-related activities ... 131

Part II The Pedagogical Aspects

Figure 19.1 A model of community-based environmental education . . . . _ . 212

List of Tables


Table 2.1

Table 2.2

Table 2.3

Table 2.4

Table 3.1

Table 5.1

Table 6.1

Table 6.2

Table 7.1

Table 7.2

Table 7.3

Table 7.4

Table 7.5

Table 7.6

Table 7.7

Table 7.8

Table 7.9

Table 7.10

Table 10.1

Table 10.2

Ecosystem components . . . . . . . . . . . . . . . 17

Major plant growth forms on terrestrial ecosystems . . . . . 21

Raunkaier’s life forms and the position of the renewal bud or organs . . . . . . . . . . . . 22

World distribution of primary production in the different ecosystems . . . . . . . . . . . . . 29

Average composition of the dry atmosphere below25km . . . . . . . . . . . . . . . _ . . 33

Population situation in major regions and selected countries . . 78

CFCs and Halons under regulations by Montreal Protocol . . . 85

Regulated level of consumption and production ofCFCZsandHalons . . . . . . . . . . . . . . . 87

Concentration of heavy metals in water in Jakarta Bay and at the upper Gulf of Thailand . . . . . . . . . . 98

Heavy metals in sediments of Jakarta Bay . . . . . . . . . 99

Ranges of heavy metals concentration in bivalves in the Philippines . . . . . . . . . . . . . . . . 99

Detection ratio of major toxic chemicals in Japan . . . . . 100

Chlorinated hydrocarbons in samples from Malaysia . . _ . 100

Standards for Mercury and PCBs for fishes in Japan . . . 100

Major pollutants discharged by each pollution source . . 101

Effects of pollutants on human health . . . . . . . 102

Mineral fertihzer consumption . . . . . . . . . 103

Mineral fertilizer consumption per ha of agricultural land . . . . . . . . . . . . . 104

Relative importance of minerals sectors,1980 . . . . 120

Percentage share of minerals in trade . . . . . . . . . 120

- -__--.-

Table 10.3

Table 10.4

Table 10.5

Table 10.6

Table 10.7

Table 10.8

Table 10.9

Table 10.10

Table 12.1

Table 12.2

Table 12.3

Principal exports of minerals and mineral prducts,l981 .

Principal imports of minerals and mineral products,1981

Relation of per capita energy and steel consumption to income . . . . . . . .

Energy/GDP ratios for the Asia-Pacific region . . . .

Differences between less developed and developed societies . . . . . . . . . . .

Metals consumption by industrial economies as a proportion of world consumption . . . . . .

Some environmental impacts of energy conversion . .

Annual emissions from a 900-MW coal-fired power plant

Illustration of Ad hoc method for comparing alternative reservoir arrangements . .

Checklist for Huasai-Thale Noi road project . . . .

Checklist for the Malabon Basin waste water treatment system . . . . . . . . . . . . .


Table 18.1

Table 18.2

Bloom’s taxonomy of educational objectives in the cognitive domain . . . . . . . . . . . . .

Bloom’s taxonomy of educational objectives in the affective domain . . . . . . . . . . . . .

Table 19.1 Examples of student projects/ activities for some environmental problems in the community . . .

121

122

124

125

127

128

134

135

154

155

156

200

200

213

INTRODUCTION

Human’s quest for improving the quality of life through the interactive process with nature is an ongoing phenomena. Scientific and technological achievements are enabling humankind to control and transform the natural environment to suit needs and demands. Indiscriminate use of this capability, however, has created a situation threatening the existence of humanity itself. What is required is a recognition of the need for both development and proper management of the environment. Also needed is a new concept of development that emphasizes the relations between human and nature being mutually supportive and sustainable from long-term point of view.

Since the Stockholm Conference on the Human Environment, two decades ago, our understanding of ecological realities has been further enriched from experiences and acquisition of new knowledge in critical areas. For the underdeveloped/developing societies, the message is quite clear that not only “poverty causes pollution” but “pollution also causes poverty”. On the other hand, affluence based on indiscriminate use of material resources and technologies for short term gains is counter productive and self defeating in the long run.

A series of themes discussed and debated in national and international forums have contributed towards re-definition of the concept of development. These definitions suggest that neo-development needs to be viewed as a diversified process involving all sectors and groups of a community on a continuing basis, seeking solutions to immediate environmental problems while ensuring the continuity of future developments. In this context, there is need for clarifying the direction and pace of development on an endogenous basis taking into consideration the society’s needs, socio-economic objectives, features of its environment and the impact of development on the biosphere. From the inital experiences in this direction, some of the essential prerequisites for the success of this approach are:

a) a clear political endorsement and active support from decision makers;

b) broad participation of local communities in the formulation and implementation of the national policies and programmes;

c) the need to build up technological and scientific data base in support of the programme;

d) a closer and stronger link between environmental legislations and economic decisions;

e) a revamp of educational system to generate and diffuse knowledge through research, teaching and extension at various levels making Environmental Education a life-long learning process.

Environmental Education

The Stockholm Conference specifically recommended that Unesco and the other international agencies will establish an international programme in environmental education. The programme will be interdisciplinary in approach to be organized in school and out of school encompassing all levels of education, directed towards the general public - in particular the ordinary citizens living in both rural and urban areas, youth and adult alike, with a view to educating them to manage and protect their environment.

Introduction 2

In a way EE has a long history linked with human’s growing interaction with the natural environment and developing appropriate attitudes towards the same. With the emergence of a formal and structured system of education, the focus became limited to imparting knowledge concerning nature rather than on developing appropriate behaviour towards its protection. Similarly, socio-cultural, economic and political dimensions were overlooked.

Presently Environmental Education is not viewed as a separate discipline or specific subject but an integral part of the total curricula. EE thus emerges as the outcome of a re-orientation of the various disciplines and of different educational experiences (natural sciences, social sciences, arts and letters), etc. This enable learners to achieve an integrated perception of the environment and to act towards it in a way that is more rational and attuned to social realities, now and in the future.

Objectives of Environmental Education

The main objectives of Environmental Education are to:

l Generate and disseminate knowledge through research, teaching and extension work;

l Develop knowledge-based awareness that will lead to cultivation of responsible attitude to environment, without losing sight of the value system of society and individual;

l Acquire skills for implementation of programmes and policies conducive to solving immediate problems and overall development of the nation.

Main Issues

Educational functionaries assigned with the responsibility of weaving these messages into educational programmes are confronted with number of issues. Some of these are:

l What is the knowledge base of environmental education particularly its multi-facet interconnections with physical, social, cultural, economic and political phenomena?

l How can these message be translated into curricula?

l Should the approach be multidisciplinary or interdisciplinary?

l How can educational progress lead to concrete action and bring about change and improvement in the existing state of affairs?

l What should be the mode of curricula transaction?

l What type of teacher training would be required in order to communicate knowledge, bring about attitudinal changes and generate commitment for environmental protection and improvement?

l What will be the mode of monitoring or feedback system to be adopted to achieve the objectives?

Sourcebook in EE for Secondary School Teachers 3

Constraints in Implementing Environmental Education

Some of the difficulties faced by implementors of Environmental Education programmes include the following:

l Rigidities of the formal system in prescription of curricula both in the school and teacher training institutes prevents the inclusion of innovations like Environmental Education into the school programme.

. The interdisciplinary nature of Environmental Education is complex and its inclusion in various discipline and consequent changes in teacher training programme conflicts with the tradition bound approaches.

l Lackof properly trained teachers to handle the Environmental Education programme.

. Environmental Education activity and field based programme necessitates different approaches and is not considered in conformity with classroom interactions.

l Teachers’ training programme in this area poses its own problems such as :

- Paucity of resource persons to conduct the training programmes;

- Lack of authentic updated materials/ information regarding environment and its associated problems;

- Non-availibility of tools to assess impact of training programmes;

- Lack of research in the field of Environmental Education methodologies and competencies;

- Resistance to change on the part of teachers.

About the Sourcebook

The sourcebook is an attempt to provide answer to some of the issues and the constraints listed above. The main target is the secondary stage of science education. The document is divided into two parts:



In addition, exemplar lesson plans, sample instruments for determining Environmental Education literacy and behaviour patterns and training tests for teachers are provided in the appendices.

In planning various chapters of the sourcebook following considerations were kept in mind:

l To provide knowledge component to the science teachers and generate a sense of urgency in view of growing environmental crisis;

l To establish a relationship between the content and teaching of Science Education and environmental component and provide a framework for the same;

l To identify objectives for Environmental Education in Science teaching;

Introduction 4

l To formulate curricula and the requisite skills for the same;

l To promote basic skills in developing problem-solving approach;

l To make teachers’ training effective by using pre- and post training tests;

l To know and practice teaching strategies relevant to Environmental Education and the basic disciplines;

l To develop criteria for evaluation and implementation of EE.


The first chapter deals with the concept of environment and environmental education. It presents a broad view of the areas of environmental concern including hazardous products, indiscriminate use of technology as in the green revolution programme, destructive fishing techniques, destruction of mangrove forests and forest resources and energy, mega projects. Educational intervention in this context is viewed in its totality and covers natural and man made environment, ecological, political, economic, technological, social, legislative, cultural and aesthetic aspects.

The succeeding chapters present the concept of ecology, the components common to the different ecosystems and their structure and function. They also discuss the energy flow and nutrients cycle in the biosphere, and how human activities affect these processes on the local and global scale. Problems discussed include degradation of forest, water pollution, due to energy and mineral extraction, warming of the earth and ozone depletion. Environmental management in the context of sustainable development is introduced as well as suggestions for environmental management and impact assessment activities.

All these topics are related to teaching of science at the secondary stage with their bearing on other subjects. The material is an important source for strengthening the knowledge base for formulation of curricula and teacher training programmes.


This section analyzes the developments in Environmental Education outlining general strategies. It also provides a sample broad framework for environmental education at secondary level. In addition, it gives various steps needed for planning and developing curricula.

The role of values is elaborated in three chapters. The assumption is that values education is not confined to cognitive learning alone. The development of values is manifested through behaviour in specific situations and extends to home and community. Thus action learning with focus on social responsibility, concern for others and harmony with nature are effective in achieving EE objectives.

In science subjects, sets of values like carefulness, objectivity, perseverance, patience, cleanliness, orderliness, cooperation with others, honesty, accuracy, and thrift in the use of materials are already part of science teaching culture. In classroom teaching, however, teachers have to highlight specific values arising out of the topic under discussion through values

Sourcebook in EE for Secondary School Teachers 5

clarification. Here the student is given opportunity to clarify his personal stand on an issue. This approach is to be used in combination with other approaches.

A summary of ecological principles with major moral implications for society is also given. They include:

l Interrelatedness within nature;

l Human as part of nature;

l Respect for nature and responsibility for its protection;

l Attitude of harmony and balance towards nature rather than conquest and mastery;

l Diversity of species leading to stability;

0 Conservation;

l Maintenance of stability and productivity of an economic system;

l Minimizing pressures on the ecosystem.

These principles are of universal nature and have bearing on social, cultural, economic and political aspects of life.

This section also suggests how knowledge, skills and attitudes about and for the environment can be achieved. One way is to study conditions in the community. Community-based EE entails: assessing community needs/resources and identifying environmental problems; relating environmental problems with science curricula; implementing environmental activities/projects for possible solutions.

Another method is to expose learners to problem solving situations. Though learning by enquiry has been part of science learning this higher order thinking skill can be enhanced by providing opportunities to practice them, using field and laboratory investigations.

In addition, educational games and simulations are suggested. Students involve in a simulation, manipulating a model or playing roles which assist them to develop an understanding of a feeling for the reality being presented. Methods of designing games and simulations related to Environmental Education are listed. Different techniques for assessing the effectiveness of these approaches are also given.

Lesson planning and development of teaching aids for environmentally oriented science classes have been given attention in this sourcebook. The focus is on the interaction between Science, Technology and Environment. The science teacher is exposed to strategies/methods for integrating these three components in classroom lessons to make the lessons relevant and meaningful. This chapter also demonstrates, that environment-oriented science lessons are not difficult to prepare. To guide them in their classroom work, exemplar lesson plans are provided.

One of the teachers role is to assess students performance. For this purpose various types of instruments are discussed. Their purpose, usability, reliability and practicability are explained. Various steps in developing these instruments are elaborated. Problems and issues pertaining to noncognitive aspects are discussed. Sample Likert scale items, practice/behaviour rating scales and sample test items are included.

To improve the implementation of EE in schools and teacher training institutes, a suggestion is made to focus on research in EE. In this chapter areas of research on environmental education are detailed and methodologies pertaining to various aspects of research are

Introduction 6

discussed. This is followed by sample-practicum exercises. In each exercise, implications for classroom teaching are highlighted.

The last section of the sourcebook includes the appendices dealing with exemplar lesson plans; sample instruments for determining environmental education literacy and behaviour patterns and sample pre-and post-training tests. This is done in the context of environmental realities in the Asean Region.

Use of Sourcebook

The sourcebook may be used by teacher trainers, supervisors and science teachers in preparing environment education curricula and pre-service and in-service teacher training programmes. The presumption is that teachers are well acquainted with the basic knowledge of science and are acquainted with the theory and practice of science teaching. They need to become familiar with environmental knowledge and practical exercises in integrating EE into science classes, using varied teaching learning methodologies and skills in assessing pupil’s achievement. This sourcebookshows that the approach and methodologies of teaching environment education and science subjects have areas of commonality and as such the process of infusion in teacher training programme can be mutually supportive and reinforcing. Some of the new dimensions like values and action orientation conform to the growing trends in science teaching which emphasize societal needs and resources.

Action Points

Effective utilization of the sourcebook in country specific situation will require various steps. Some of these are listed below:

l Situational analysis of existing science curricula, teachers’ training programmes and infrastructural facilities;

l Place of environment education in the science curricula and estimation of additional requirements;

l Needs assessments of teachers in terms of:

- scope of training keeping in view the environmental issues of the country concerned, state of existing knowledge and skills of teachers and identification of gap areas;

- training content in terms of knowledge, pedagogy, skills and expected change in attitudes and behaviour;

- training methodologies and its applicatiality to the methodologies already in use;

- training resources in terms of experts and institutions and training materials;

- impact evaluation feedback and continuous efforts for improvement.

The sourcebook provides necessary knowledge and methodology in major critical areas of teacher training. The relational exercise with reference to actualities of field situation and also mobilization of necessary training resources will have to be country-specific.

Chapter 1

.

.

The Concept of Environmental Education*

Definition

To tackle this topic, we must first define the term “environment” and for this purpose we will consider what a Brazilian scientist has written. The environment is not only the sum of all the material things that constantly interact with each other and which make up the mosaic of the countryside landscape. It is much more than this. It also includes the economic structures and the outlook and habits of peoples in different parts of the world. The environment as a whole therefore includes not only the physical or material factors but the economic and cultural ones as well.

An accurate analysis of the environment must always consider the impact of human beings and their culture on all the surrounding elements and the ecological factors on every aspect of human life.

The concept is much wider and more objective than that which considers the environment merely as a system of mutual relations between living creatures and their natural environment (Jose de Castro, 1974).

The term “environment” has to be defined since we cannot know the aim of “environmental education”without first determining the structures, functions and dynamics of the environment. We should be aware, too, that when ecologists and naturalists talk about the “environment”, they use the word in a different sense from that of architects, doctors, sociologists, engineers, geographers, or perhaps anthropologists.

The Philosophy and Aims of Environmental Education

Based on the guidelines laid down at the seminar held in Belgrade in 1975 under the joint sponsorship of Unesco and UNEP, a start has been made on the task of drafting, organizing and developing environmental education programmes. These programmes are designed for primary, secondary and university levels.

There are various approaches to the development of environmental education, a number of which follow:

* Prepared by Dr. Ruben B. Aspiras, Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines at Los Babes.

Part I - The Knowledge Base 8

l Environmental education is offered as a type of education with a distinct bias for ecology. This means an offering of one more subject on the curriculum which becomes more complicated as it reaches the higher levels in the educational system. This is possible only if its inclusion throughout the educational process is accepted.

l Environmental education is given as bias incorporated in all the subjects in the curriculum. This approach will not result in altering the subjects in the curriculum but it will require teachers to give the subjects an ecological slant towards environmental problems. A lengthy and costly training on the part of the teachers may be a formidable drawback in carrying out this task successfully.

l Environmental education is given as a fresh style of education which will seek to make pupils fully aware of the problems connected with their environment and teach them new attitudes and behaviour to enable them, together with the other members of their community, to contribute to their solution.

A Chilean ecologist claims that the aims of environmental education concerned with solving environmental problems are:

1. To develop new attitudes and behaviour patterns in pupils which enable them to make decisions concerning the necessity of preventing the deterioration of the environment, through respect for ecological equilibrium, greater solidarity with and love of nature, and increased involvement with the natural environment.

2. To increase awareness of our responsibility for our actions in relation to the environment and their immediate and long-term repercussions. (This aim should also lead students to become aware of the actions of others considering that the most dangerous polluters are not individuals, but large industrial and agricultural concerns, whether publicly or privately owned.)

3. To protect and preserve natural resources and, hence, to use them rationally, in the light of the ecological situation in each particular country.

4. To help bring about a technological world which is consistent with the real needs of individual development and the social development of each country and which does not conflict with its cultural patterns; and to develop appropriate technologies and introduce only those technologies which are suited to local or regional circumstances.

5. To increase the part played by technical education in the existing educational system, so that solutions to problems are evolved in each country’s circumstances, and not imported from abroad (L. F. Capurro, 1976).

In regard to the origin of technologies, it should not be assumed that technologies imported from outside are bad technologies and indigenous technologies good. A technology in itself is neither good nor bad. Its badness stems from its application when the natural resources that belong to the many are used for the benefit of the few, or when they pollute the public environment. A good technology is one which is employed in ecodevelopment (sustainable development) aimed at the economic and cultural development of mankind without causing too much damage to the regenerating processes of the biosphere. We need to identify and develop educational programmes that focus on the causes rather than just the symptoms of the environmental crises. It is imperative, therefore, that we become acquainted with the environ-

The Concept of Environmental Education 9

mental crises, more particularly in the Third World, so that we will be able to develop comprehensive action programmes to resolve them.

Environmental Crises as Products of the Adoption of Western Systems

Most countries in the Third World went through colonial rule and were subjected to imposition of new economic systems and industrial exploitation of natural resources. Conse- quently, new consumption styles and new values were acquired and new products and technologies were imported. The transactional corporations became the dominant force in the economics of most Third World countries. The Third World countries were given aid by multilateral institutions like the World Bank and transactional banks that provided them loans of billions of dollars to support expensive projects and the importation of capital intensive technologies. In the process, Third World countries were sucked into the whirlpool of the world economic system resulting in the degradation of their resource base and the destruction of their self-reliant capacities.

Hazardous Products and Technologies

Many industries in the developed countries are shifting their markets to the Third World where they can sell highly toxic products banned in the exporting countries themselves.

The survey carried out by the UN Food and Agricultural Organization found that highly toxic pesticides were widely available in at least 85 developing countries. Furthermore, it says 80 of these countries have no adequate system to approve, register or monitor the toxic materials. These countries also lack information about hazards and do not have trained people to evaluate them. The sales of pesticides have nearly doubled since the mid 1970s to nearly $18 billion a year. Much of this sales growth has taken place in the Third World.

The World Health Organization estimated in 1986 that as many as one million people, among them farmers in the Third World, suffer from acute poisoning from pesticides every year. Pesticide poisoning causes an estimated 20,000 deaths a year.

In the Philippines, the widespread use of toxic pesticides by rice farmers in Nueva Ecija, Central Luzon resulted in increased mortality by as much as 27 per cent (Loevinsohn, 1987).

The Green Revolution

Considering the limitations of land area, agriculture has to be intensified in areas already under cultivation. In the recent past, intensification took the form of large technological inputs that were fossil fuel based. With the increase in cost of energy and the resultant pollution of the environment by extensive use of chemicals, there is every reason to change the present strategy of crop production to a more appropriate one. However, the development of new technologies by many of our research institutions is not necessarily taking a favourable turn.

When an insecticide is used in a rice field both the harmful and the useful organisms are killed, resulting in the simplication of the insect fauna of the farm ecosystem. This means that the natural capacities for self-stabilization are lost. In this case, the natural stabilizing mechanisms have been compensated by technological inputs. This approach, when practiced over wide areas, results in high vulnerability of crops to pests and diseases. High yielding rice


varieties, for example, when grown in large areas would lead to simplification of the environment. These varieties are bred for their high yielding characteristics under conditions of high fertility and excellent water control. Ironically, these genetic qualities have made these varieties vulnerable to pests and diseases. To compound the problem, only very few of these varieties are grown over large areas, a situation favourable for the build-up of pest and disease populations that can overcome the limited genetic resistance within a very short period of time. This means that there is always a danger of a major outbreak of pests or disease arising from continuous monoculture.

There is great need for appropriate pest management with a strong bias for biological control which is specific, long lasting and non-pollutive. However, such an alternative would have to be evolved after long, painstaking research. At present, research on biological control is only at its early stages.

Destructive Fishing Techniques

In many Third World countries, fish is the main source of protein and fishing is a major economic activity. In traditional fishing, the nets and traps used are simple and ecological principles are adhered to. The mesh size of nets is large enough to allow small fish to escape. The breeding grounds are never disturbed. Coral reefs continue to serve as rearing and feeding grounds for diverse fish species and as a protective barrier against the damaging effect of waves. Coral reefs are considered one of the most productive ecosystems, their productivity exceeding that of the open ocean (White, 1984).

The introduction of modern fishing techniques such as ‘muro-ami’, ‘kayakas’ and blast fishing resulted in tremendous destruction of coral reefs. Muro-ami was introduced in the Philippines by the Japanese and became widely accepted in many rich fishing grounds. As a result of its use the corals were converted into rubble with very little chance of regrowth. Kayakas, a modification of muro-ami, is equally destructive. Blast fishing is destructive both to the fishes and to its practitioners.

The destruction of corals is cause for major concern considering the fact that corals take around 38years to regrow to half of their original size (Alcala and Gomez, 1969). Under ordinary conditions, corals are under pressure from their natural enemy, the starfish, popularly known as the “crown of thorns”, and scientifically called Acanthaster planci.

Destruction of Mangrove Forests

There is widespread destruction of mangrove trees for firewood, charcoal, and commercial products such as rayon, tannings and dye. More recently, mangrove swamps are cleared to give way to prawn farming. In Negros Occidental, Philippines the mushrooming of prawn farms is gravely affecting the water resources of the province. There are about 200 prawn farms throughout the province that pump freshwater into their farms for mixing with seawater to produce brackish water suited to prawn culture. Prawns from these farms are exported to rich countries like Japan.

The excessive withdrawal of ground water by prawn farmers allows the entry of seawater into the system. Under this situation, the residents are complaining that they can hardly lind potable water in the area. It must be added that the rivers in Negros Occidental are so polluted with wastes from sugar mills and other factories in the area that their water cannot be used for prawn farming.

The Concept of Environmental Education 11

Forest Resources Logged for Export to Rich Countries

The tropical rainforests are considered the earth’s oldest and richest ecosystems. About 80 per cent of the world’s tropical rainforests have disappeared already, and the rest are being felled and burned at the rate of 11 million hectares a year. The richest lowland areas are the most vulnerable. The plant communities of South East Asia are the most species-rich in the world, but those of the Philippines and Malaysia are being harvested at an extremely fast rate and are expected to vanish in a few decades.

.

Massive deforestation has multiple ecological and social consequences, including the loss of land rights and way of life (or even life itself) for millions of tribal peoples of the Third World, massive soil erosion and loss of invaluable top soil and much reduced intake of rainwater in catchment areas resulting in excessive water run-off as flash floods during rainy days and drought during dry months. There is now growing concern about climatic changes resulting from forest denudation.

Tropical forests are experiencing a very rapid rate of exploitation by timber companies for log export to the rich countries or for conversion to grazing land for cattle to support the hamburger industry in the United States.

Energy Mega-Projects

The two common mega-projects in the energy sector are the large hydroelectric dams and nuclear power plants. Both of these projects entail large investments and bring about serious problems and risks. In the case of the huge dams, large tracts of forested areas are flooded, including human settlements, thus causing disruption in the way of life of thousands of people living in the affected forests. In many instances, however, the dams do not reach the expected lifespan because of excessive siltation. Siltation and soil erosion result partly from forest denudation in the watershed area and partly from the very.low rehabilitation of the critical portions of the watershed. This means that from the start of the dam project, it is already known that the project is not expected to yield stable productivity, pointing up to less and less benefits for future generations.

A conceptual change in the project plan is needed so that in place of the dam as the focus of analysis, the whole watershed would now be considered. This will mean that with the watershed as the major capital asset in the investment analysis, the project development would then involve some amounts of money for reforestation and erosion control prior to dam construction. This is an example of how ecology can provide a new dimension toward enhancing the goals of development.

In the case of nuclear plants there is always a possibility that those plants sold to Third World countries may be of substandard quality. Take the case of the Philippine nuclear power project. Westinghouse Corporation built a nuclear power plant for US$2.2 billion but because of so much doubt about its safety, the Aquino government has decided to “mothball” it. Even if declared safe tooperate, there is always a possibilityofan accident and there is also the attendant problem of nuclear waste disposal.

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Toward Establishment of the Curriculum

After discussing some of the most critical issues facing society, we can now use this knowledge in embarking on the formulation of a suitable environmental education curriculum. Some Guiding Principles of Environmental Education could be to (adapted from Stapp, 1978):

Consider the environment in its totality - natural and man-made; its ecological, political, economic, technological, social, legislative, cultural and aesthetic aspects.

Be a continuous life-long process and should begin at the pre-school level andcontinue through all formal and non-formal stages.

Be interdisciplinary in its approach, drawing on the specific content of each discipline in making possible a holistic and balanced perspective.

Emphasize active participation in preventing environmental problems and working toward their solution.

Enable learners to play a role in planning their learning experiences and provide an opportunity for making decisions and accepting consequences.

Focus on current and potential environmental situations.

Explicitly consider environmental aspects in plans for development and growth.

Promote interrelationship of peoples and environment.

Examine environmental issues from local, national and international points of view so that learners receive insights into environmental conditions in other geographical areas.

Focus on the learner’s own community and relating topics being discussed to national, regional and international issues and perspectives.

Relate environmental sensitivity, knowledge, problem solving and values at every grade level, but with special emphasis on environmental sensitivity in the early years.

Emphasize the complexity of environmental problems and the need to develop critical thinking and problem solving skills.

Utilize diverse learning environments and a broad array of educational approaches to teaching/learning about and from the environment with due stress on practical activities and first hand experiences.

In establishing an environmental education curriculum, we should construct a model designed to be action-oriented and comprising the following integral parts: philosophy and concepts; skill development; the environmental encounter; emphasis of programme at different age levels; teacher-learner interaction; and sensitivity guidelines.

Chapter 2

Structure and Function of the Ecosystem*

What is Ecology?

The term ecology is derived from the Greek word &OS meaning “house” or “place to live”. Literally then, ecology is the study of organisms at home or in places where they live. Although the word ecology has become part of our daily vocabulary only during the last three decades or so, the science of ecology has been recognized as a distinct field of biology since the turn of this century. Its roots lie in natural history: from the Greek philosophy on the providential design and balance of nature during Plato’s time to Darwinian theories on natural selection and evolution.

Ernst Haeckel, a German zoologist, first defined the word ecology in 1869 as the total relations of the animal to its inorganic and organic environment. This initial definition has since been expanded to include plants and now ecology is invariably defined as the study of plants and animals in relation to their environment. Such a concept, however, is too broad and encompassing for ecology would then overlap with other biological disciplines - notably physiology, genetics, behaviour and evolution. Charles Elton’s (1927) definition of ecology as scientific natural history is likewise broad and rather vague.

Subsequent definitions tried to restrict and clarify the intents of ecology. Andrewartha (1961) viewed ecology as the scientific study of the distribution and abundance of organisms. Since ecology emphasizes dynamic relationships, Andrewartha’s restrictive definition is rather static and may be improved so as to consider ecology as the scientific study of the interactions that determine the distribution and abundance of organisms (Krebs, 1985) through space and time. Odum’s (1963) definition of ecology as the study of the structure and function of nature likewise underscores dynamic structure-and-function relationships but lacks clarity and objectivity in scope. All these definitions, however, are in unison in stating that ecology, as a discipline of biology, attempts to understand and explain where organisms live, how many and how they live there, and, hopefully, why they occur there.

The distribution and abundance of organisms basically reflect their successful integration with the environment. The three levels of integration which ecology primarily deals with are: individual organisms; populations; and communities. Distinct attributes and properties characterize each level. For example, individuals get integrated with their environment through the

* Prepared by Dr. Reynaldo k Tabbada. Professor, Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City.

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establishment of their niche and specific behavioural patterns. Any given population has density (number of individuals per unit area), an attribute which is impertinent and meaningless to an individual. Similarly, species diversity as a property of the community cannot be ascribed to the population level. The specific attributes of a lower level of integration, however, are most useful in explaining or describing mechanisms operating at higher levels of integration. Hence, to understand changes in species diversity in a community an ecologist will have to look for explanations from the fitness or interactions of populations or individuals. Thus it has been proposed that the ecosystem, with its biotic community and abiotic environment, is the basic unit of ecology (Tansley, 1935; Evans, 1956; Rowe, 1961; Billings, 1964).

The Ecosystem

In nature, living organisms do not exist as independent individuals or populations but in association with a few or a great many other plants and animals. These associations are not haphazard or incidental aggregations. Rather, they are spatially and temporally ordered and arranged, organized like machines which utilize energy and raw materials in their operations and interactions. Any spatial or organizational unit made up of living organisms and non-living substances or conditions that interact to produce an exchange of materials is called an ecosystem. In short, an ecosystem refers to a situation where living or biotic units function together with their environment. As the term implies, it is a system which is made up of interdependent living and non-living structures enclosed within a defined boundary.

The term “ecosystem” was coined by Tansley (1935) and explained as:

‘I... the whole “system” (in the sense of physics) including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment . . . We cannot separate them (the organisms) from their special environment with which they form one physical system . . . so formed which (provides) the basic units of nature on the face of the earth . . . These “ecosystems”, as we may call them, are of the most various kinds and sizes.”

Thus the “eco” of the term refers to the environment and the “system” indicates a complex of coordinated or organized units.

Asystem is made up of a set of interdependent or interacting parts or subsystems enclosed in a defined boundary. The concept of a system as used in ecology as well as other branches of science focuses on functional or working relationships between objects or subsystems rather than on the individual objects themselves. Thus, in ecosystem studies, one focuses on the organisms functioningwith theenvironment rather than just studying the individual populations of plants and animals. The systems approach in the study of natural habitats not only yields a lot of information about the abundance and distribution as well as functioning of biotic units, but also forms the basis of the management and conservation of the environment and its resources.

There are two basic types of systems (Fig. 2.1): The closed system where no materials or energy pass through the external boundaries of the system, and the open system wherein materials or energy enter and leave the system. In the open system, the entries or gains of materials and energy are termed inputs while the exits or losses of materials or energy are called outputs. The exchange of materials or energy between subsystems or components within the system is termed throughput. Except for the universe, all systems in nature, including the ecosystems of ecology, are open systems. The extent of openness, however, varies from one

INPUT

The Ecosystem 15

------ system boundaries

ii--

interactions within the system subsystem or system components

CLOSED TYPE

b OUTPUT

OPEN TYPE

Figure 2.1. The closed and open types of systems.

ecosystem type to another: a river ecosystem where water currents constantly carry materials downstream or elsewhere is more open than a lake or a pond ecosystem.

Natural ecosystems vary in scale of size and self-sufficiency. The largest and, perhaps, almost completely self-sufficient ecosystem is the global ecosystem which is referred to as the biosphere or ecosphere which includes all of the earth’s living forms interacting with their environment. Smaller in scale would be marine ecosystems, forests, grasslands, agricultural fields, lakes, rivers, and ponds, among others. A few drops or a pool of water with its component organisms functioning with the aquatic environment also theoretically qualifies as an ecosystem. Although some habitats, such as islands or forest areas have clearly defined or distinct boundaries, in other ecosystems the spatial limits are often arbitrarily set depending on the objectives and interests of the ecologist.

All ecosystems, however, have certain basic features of structure and function in common, regardless of their position in the scale of size and self-sufficiency or the clarity or arbitrariness of their boundaries. Natural ecosystems all have biotic or living and abiotic or non-living components which function together in the exchange of materials and energy (Fig. 2.2). These interactions give rise to a definite structure and function which would be characteristic of a given ecosystem. To understand and, perhaps, better appreciate ecosystem structure and function, there is a need to consider the biotic and abiotic components or subsystems of the ecosystem.


Owen Carbon Dioxide Water

Radiant Energy Nutrients

f c Ic PRODUCERS

c Green Plants Photosynthetic Bacteria Chemosynthetic Bacteria

v PRIMARY CONSUMERS

r Herbivores Plant Parasites

ESSENTIAL INORGANIC NUTRIENTS

Macronutrients Micronutrients SECONDARY CONSUMERS

& Carnivores A Omnivores

Animal Parasites Scavengers

v v DECOMPOSERS

Saprophytic Bacteria 4 Fungi

t Oxygen Carbon Dioxide Water

t f Heat Energy Nutrients

Figure 2.2. Biotic and chemical components of the ecosystem.

The Ecosystem 17

.

Ecosystem Components: Biotic and Abiotic Factors

The two basic components of the ecosystem are the biotic and the abiotic parts (Table 2.1). The three major groups of living forms that constitute the biotic part are the producers, consumers and decomposers. The green plants, ranging in size from the microscopic phytoplankton of aquatic habitats to the gigantic trees of the tropical rain forest, are the main producers in the ecosystem. These organisms harvest light energy of sunlight and utilize this in the synthesis of sugars from carbon dioxide and water in a process known as photosynthesis. Just like green plants, the photosynthetic bacteria also undergo photosynthesis. There are also some bacteria, the chemosynthetic forms, which utilize the chemical energy of simple inorganic substances in the synthesis of carbohydrates. The green plants together with the photosynthetic and chemosynthetic bacteria produce their own food and are thus termed autotrophs or self-nourishing organisms. Among these producers, however, the green plants account for the bulk, if not all, of organic matter production in the ecosystem. Except in some habitats, the contribution of the autotrophic bacteria to organic matter production has been considered to be ecologically insignificant. Carbohydrates are basically the building blocks from which foodstuffs, such as protein and fats, are made in living organisms.

Table 2.1. Ecosystem components.

I BIOTIC PART ABIOTIC PART

1. Procedures 1. Climatic Factors

1.1 Green plants 1.1 Light

1.2 Photosynthetic bacteria 1.2 Temperature

1.3 Chemosynthetic bacteria 1.3 Precipitation

2. Consumers 1.4 Atmosphere and Wind

2.1 Herbivores 2. Edaphic Factors: Soils

2.2 Carnivores 2.1 Nutrient Content

2.3 Omnivores 2.2 Acidity

2.4 Detritivores 2.3 Moisture Content

3. Decomposers 3. Topographic Factors

3.1 Bacteria 3.1 Aspect

3.2 Fungi 3.2 Angle of Slope

3.3 Altitude

The consumers are animals which obtain their food by eating plants or other animals. They cannot make their own food and are thus called heterotrophs or organisms that feed on other living forms. Herbivores, including plant parasites, eat only plants. Carnivores, including animal parasites, feed only on other animals. Omnivores eat both plants and animals while detritivores feed only on dead plant and animal materials. Consumers essentially convert ingested food into new protoplasm. The ultimate source of the food energy obtained and used by consumers is the organic matter produced by autotrophs in any ecosystem.


The decomposers are micro-organisms, notably the so-called bacteria and fungi of decay, that break down the complex organic molecules of the litter, wastes and remains of both producers and consumers. Decomposition leads to the release of simple inorganic substances that can be reused by green plants. Decomposers are as essential a part of the ecosystem as producers and consumers; in their absence, the basic elements of life would become locked in the complex molecules of the wastes and remains of other living forms, rendering them unavailable to the producers in the ecosystem.

Abiotic Factors

The abiotic component of the ecosystem consists of three major factors: the climatic; edaphic; and topographic profiles of a given habitat. The fundamental characteristics and features of any ecosystem are determined largely by its abiotic factors which serve as basic controls on the ecosystem as a whole. As such, organisms, populations and even communities are often said to be at the mercy of their environments and must struggle to maintain homeos- tasis or equilibrium with their immediate surroundings.

Light, temperature, water availability and wind are, from an ecological perspective, the major climatic factors that significantly influence the biotic community in the ecosystem. Practically all of the energy in an ecosystem originates as radiation from the sun or solar radiation consisting of electromagnetic waves of a wide range in length. Solar radiation reaching the earth’s surface or the biosphere, however, consists mainly of wavelengths measuring between 300 and 700 millimicrons (mu), visible (to the human eye) radiation lying between 390 and 760 mu, infra-red or thermal radiation above 760 mu, and ultra-violet radiation below 390 mu. Light has three aspects which influence the biotic community in the ecosystem: intensity or energy content; quality or wavelength composition; and duration or day-length which refers to the number of hours of light received each day. Variations on these three properties would regulate, directly or indirectly, different physiological and morphological processes in both plants and animals. For instance, light intensity and quality, to a high degree, determine the rates of photosynthesis in both terrestrial and aquatic habitats. Day-length or photoperiod influences the initiation of flowering, dormancy and leaf-fall in higher plants as well as the onset of migration, hibernation, nesting and even changes in coat colours among animals.

Radiant energy from the sun when absorbed by molecules of gases, liquids, or solids raises the temperature of the absorbing substance. Temperature differences cause the flow of energy in the form of heat from warmer substances or sites to colder substances or places. Temperature, then, is essentially a measure of the tendency of a substance to release heat. There are two important aspects of temperatures: absolute and relative. The absolute temperature controls the speed of biological and physical reactions as well as the heat lost by radiation from a body or surface. The relative temperatures of organisms and other components in the ecosystem indicate the direction and rate of heat flows in the environment. Temperature, as an environmental factor, acts both directly and indirectly on the biotic community. It directly affects the functioning of organisms by controlling their body chemistry. It also acts indirectly by influencing the status of other environmental factors, as in the case of evaporation which largely determines water availability in terrestrial habitats. Most living forms function within a temperature range of between 0 and 50 degrees C. Within this range, individual organisms have cardinal temperatures which are the minimum, maximum and optimum temperature requirements for their metabolism.

The Ecosystem 19

Water constitutes the bulk of the living tissues of plants and animals. Most physiological and biochemical processes occur in an aqueous matrix. Water is the medium of life in aquatic habitats but, as a soil factor, is unevenly distributed in terrestrial ecosystems such that its scarcity or abundance is largely responsible for the dramatic differences in the vegetation; the wet and dense tropical rain forests in contrast to the sun-baked deserts with their sparse and scattered scrubby vegetation. Differences in precipitation and solar radiation largely account for the variations in water supply which basically determine the functioning of terrestrial habitats. Evapo-transpiration is the loss of water from the ecosystem; evaporation from surfaces and transpiration from the vegetation.

The atmosphere contains mainly nitrogen and the vital gases oxygen and carbon dioxide. It is a vast gaseous reservoir that permeates the whole surface of the earth and its biotic habitats. The atmosphere in motion is the wind. Strong winds may directly induce physical damage or cause malformation on plant structure in terrestrial communities. Wind action may accelerate the process of transpiration by removing water vapour from the ambient air of the vegetation, allowing further evaporative loss of water from leaf surfaces through the stomata1 apertures.

Edaphic factors are environmental controls which are dependent on the soil, the upper weathered layer of the earth’s crust influenced by plants and animals. It harbours biotic communities which include, among others but especially, bacteria, fungi and other organisms that fix atmospheric nitrogen, decompose organic matter and incorporate it with mineral matter. In terrestrial habitats, the soil, serving as a medium for plant growth, provides anchorage for roots, water supply, essential inorganic nutrients, and aeration for the respiration of roots and decomposer organisms. The soil, then, acts as a water and mineral reservoir and a habitat for microscopic decomposers, atmospheric nitrogen-fixers and other animals. The nutrient and moisture contents of the soil are basic limiting factors that largely determine the nature and distribution of the vegetation and, consequently, community types. Soil acidity, or pH, determines the solubility and availability or the fixation and non-availability of essential inorganic salts in the soil solution. Hence, the acidity of the soil influences the potential absorption of essential nutrients by plants since only the soluble forms are absorbed. Ecologically then, soil acidity is an initial critical factor in the recycling of soil nutrients - salts rendered insoluble due to soil acidity or alkalinity will not be available to plants.

Topography or surface relief tends to modify the climatic factors in the environment that may change vegetation types. The aspect or slope orientation of a particular habitat determines the amount of solar energy received at the surface, especially at middle or high latitudes. Slopes directly facing the sun are warmer and, hence, more productive than those under shade conditions. Hence, marked differences in population distributions between slopes of a contrasting aspect can be observed. The angle of slope or the steepness of the slope affects both drainage and surface stability. Communities more tolerant of dry conditions are generally found along steeper slopes. Gentle slopes are suitable habitats for mesophytic vegetations with seasonal variations in water supply.


Ecosystem Structure

Ecosystem structure has two dimensions: the physical and biological structure. As the phrase implies, the physical structure is essentially what one sees and notes when viewing or appreciating a given ecosystem. Walking through a grassland, one notices herbaceous plants of different heights and habits; there are short or tall and creeping or erect forms. Distributed within this herbaceous structure are animals of different sizes and forms. These impressions or appearances are part of the structure of a grassland ecosystem. The biological structure has more dynamic components in terms of temporal changes in biotic and abiotic components and relationships between species in terms of their roles or niches in the ecosystem. Species diversity and abundance also contribute to the biological structure of a given system.

Physical Structure

The structure of any ecosystem has three basic components: growth or life forms of green plants; vertical stratification of biotic populations; and seasons or climatic cycles.

Growth forms refer to the different types of the visible structure or morphology of plants, the producers in the ecosystem. Table 2.2 presents the major plant growth forms found in land-based or terrestrial ecosystems (Whittaker, 1975). Major categories are based mainly on plant height and the presence or absence of woody tissues: trees; lianas; shrubs; epiphytes; herbs and thallophytes. Except for lianas and epiphytes, each major growth form can be further classified by leaf, stem, and root morphology or physiology as in leaf fall or deciduousness. These growth forms, which are quite distinct from species or taxonomic composition, constitute a visible physical structure which can serve as a broad basis for the recognition and classification of terrestrial communities or ecosystems (Beard, 1973).

A Terrestrial Ecosystem

The Ecosystem 21

Table 2.2. Majorplant growth forms on terrestrial ecosystems (after Whittaker, 1975)

Major Growth Form and Sub-Growth Forms

1. TREES (largely woody plants, well above 3 meters in height)

1.1 Needle-leaved

1.2 Broadleaf evergreen

1.3 Evergreen-sclerophyll

1.4 Broadleaf-deciduous

Examples

conifers

tropical/subtropical trees

desert trees

trees in temperate zone and dry subtropical areas

1.5 Thorn trees (with spines)

1.6 Rosette trees (unbranched)

2. LIANAS (woody climbers or vines)

3. SHRUBS (smaller woody plants, below 3 meters high)

3.1 Needle-leaved

some legumes

palms, tree ferns

3.2 Broadleaf evergreen

3.3 Broadleaf deciduous

3.4 Evergreen-sclerophyll

3.5 Rosette shrubs

3.6 Stem succulents

3.7 Thorn shrubs

yucca, agave, aloe

cacti

3.8 Semishrubs (upper branches die back during unfavorable conditions)

3.9 Dwarf shrubs (spreading near ground and less than 25 centimeters high)

4. EPIPHYTES (aerial plants)

5. HERBS (without perennial above-ground parts)

5.1 Ferns

5.2 Graminoids

5.3 Forbs

grasses, sedges

herbs other than fern and graminoids

6. THALLOPHYTES (without vascular tissues)

6.1 Lichens

6.2 Mosses

6.3 Liverworts


Another widely used classification scheme that also describes the physical structure of terrestrial ecosystems is the use of life forms as originally proposed by Raunkaier (1934). Life forms are based on the position of the renewal or reproductive bud or organ of the plant (Table 2.3). Phanerophytes, epiphytes and chamaephytes reproduce normally through the formation of seeds which are aerial in position in the first two life forms and appressed to the ground in the third. Renewal buds of the hemicryptophytes or tussock plants and the crytophytes or earth plants are located below the soil surface in the form of extensive rhizomes or bulbs. Therophytes complete their life cycle in one growing season and survive or reproduce as seeds. While herbs produce no perennial above ground woody stems, the thallophytes form no vascular tissues. Raunkaier’s life form scheme reflects varying adaptations of plants for survival and persistence under different environmental conditions: aerial buds facilitate cross pollination or fertilization while underground buds are protected from predation or unfavourable cold or dry periods.

Table 2.3. Raunkaier’s life forms and the position of the renewal bud or organ.

Life Form Position of Renewal Bud

Phanerophytes aerial

Epiphytes aerial (without roots)

Chamaephytes on ground surface

Hemi-cryptophytes just below ground surface

Examples

trees, shrubs, lianas, herbs

orchids

rosette herbs

grasses and sedges

Cryptophytes or Geophytes below soil surface in the perennial plants forming form of a bulb or rhizome bulbs or rhizomes

Therophytes annual plants producing seeds

rice, corn, tomatoes

The biotic units in the ecosystem exhibit a vertical structure or stratification. Although vertical layering in both terrestrial and aquatic habitats is associated with light conditions, the source of stratification is different. Competition for light primarily determines the vertical structure of terrestrial ecosystems. Plant growth forms, especially in terms of height and leaf arrangement, vary in their ability to intercept light. Taller plants naturally harvest more light. Of the two extreme types of leaf arrangement types: the monolayer (wherein leaves are formed in one continuous layer) and the multilayer (wherein leaves are loosely scattered among several layers) the former would be more efficient at low light conditions and the latter at high light intensities. Vertical stratification is most prominent and distinct in many forest ecosystems with canopy trees forming the uppermost layer, understory trees, shrubs and the ground layer.

The Ecosystem 23

In contrast with the structure imposed by the different strata of the vegetation in terrestrial habitats, the vertical structure in aquatic ecosystems is provided by the physical properties of water. The density of water varies with temperature and salinity, which properties give rise to distinct vertical stratifications in aquatic environments. A lake ecosystem, for instance, may be stratified in terms of temperature and oxygen: the surface waters would be warmer and relatively more oxygen-rich than deeper sections of the lake. Light penetration in aquatic habitats is also stratified. Most of the blue and red regions are absorbed or reflected in the surface waters while the deeper waters receive m&tly the green and yellow wavelengths of the solar radiation. This vertical stratification of light quality and intensity influences the vertical distribution and migration of aquatic plants. Those that live in the open zones of lakes and in the open ocean, the so-called phytoplankton, are microscopic in size but must float to intercept light in the surface waters. Many grazers in aquatic ecosystems, the so-called zooplankton, undergo vertical migration, moving to the surface at night and sinking into deeper waters during the day time. Among fish and other animal populations, some are surface-water dwellers or swimmers and are termed neustons while others, the so-called nektons, freely move up and down the aquatic habitat. Still others, like clams and oysters, spend most of their time at the bottom and are termed benthos.

Another feature of the physical structure of the ecosystem is the occurrence of seasonal changes. The study of seasonal changes or seasonalities in the ecosystem is called phenology which basically aims to calendar biological events in terms of periodicities in environmental factors, notably temperature, daylength of photoperiod and moisture supply. The timing of biological events is quite critical for biotic interactions. The onset and duration of flowering in terrestrial plants, which is in most cases influenced by temperature and daylength, are critical in terms of competition for pollinator populations and food supply for flower or seed predators. Seasonal leaf-fall in terrestrial environments is closely linked with available moisture and peaks in the activities of decomposers. Seasonal variations in population abundance are also a common phenomenon in both terrestrial and aquatic eocsystems; the seasonal migration of some bird species to avoid unfavourable conditions in their natural habitats and the breeding behaviour of some fish species which spawn in nutrient-rich sites quite far from where they normally thrive. Such seasonal changes in the ecosystem basically reflect adaptations evolved by plants and animals to enhance their survival and reproductive fitness in any given environment.

Biological Structure

The biological structure of an ecosystem depends in part on its physical structure and involves three aspects: temporal changes; species composition; and abundance and relationships between species.

A most important feature of the ecosystem is change on an ecological time scale. The two major types of temporal changes are directional changes in time, which are commonly referred to as succession; and nondirectional changes in time which are cyclic in nature. Although the concept of succession was initially described by Cowles (1901) it was Clements (1916, 1936) who defined and developed the classical theory of succession: the vegetation as a biotic community behaves as a highly integrated superorganism and develops through a process of succession to a single end point, the climatic climax, in any given habitat. The basic assumption or strategy in the theory of succession is that species replace one another through time because at each stage the resident species modify the environment in such a manner that it becomes less suitable for themselves and more available or accommodating for others. The sequence of


communities in the process of ecological succession is termed the sere. A seral stage refers to a specific community at a distinct phase during succession, when it is the stable community that is self-perpetuating and apparently in equilibrium with the abiotic and biotic environment. Although most studies on succession have been done on the vegetation, the same concepts can equally be applied to animal communities.

As shown in Fig. 2.3, there are at present three models on the directional changes in vegetation structure during succession: the facilitation; inhibition; and tolerance hypotheses (Connell and Slatyer, 1977). The first model proposes that species replacement in later stages of succession is facilitated by resident populations in earlier stages through modification of the environment. The inhibition model looks at succession from an entirely different perspective: species replacements are inhibited by earlier resident species and seral stages are determined primarily by which species get firmly established first in the area. In short, any resident species inhibits or suppresses new colonizing individuals - hence, there is no facilitation or orderly sequence of replacement. The third hypothesis is a compromise between the facilitation and inhibition models: any species can start the process of succession and replacements are determined solely by the competitive ability of different species to exploit vital resources and tolerate the presence of limiting factors or conditions in the ecosystem.

Facilitation Model : orderly sequence of species replacements.

A------+6-C-D 3

Tolerance Model : competitive hierarchy in species replacement

Inhibition Model : all species replacements possible

A-B

C-D

Figure 2.3. The three models of succession in the ecosystem. A, B, C, D represent four dominant species or populations. Arrows indicate species replacement. (source: Horn, 1981)

The Ecosystem 25

Community changes that do not produce directional serial stages or end in a climax state are cyclic in nature (Fig. 2.4).

These nonsuccessional and cyclic changes are basically initiated by species interrelations which are repeated over and over and occur only in a limited scale in a few ecosystems. The studies of Watt (1947) in a healthy vegetation indicated the involvement of different stages in a cyclic change: pioneer; build-up; maturation; and degenerative phases. The first stage includes the establishment and early growth of the dominant species in a bare area. This is followed by the build-up of biomass by the dominant species to attain a maximum cover. The maturation phase is characterized by the loss of vigor in the dominant species and the creation of gaps or open spaces that can be colonized by invading species. At the last stage, the dominant species senesce and degenerate to give way to the invading species. After some time, the invading species also degenerate and die to again create a bare area to be colonized by the previous dominant species. Thus the cycle is again repeated. The life cycle of the dominant species controls the cyclic changes which are initiated mainly by a decline or loss in its vigour.

Another dimension of an ecosystem’s biological structure is species composition and abundance. Although all ecosystems do contain a mixture of species, they vary in the number of resident species which likewise vary in the number of individuals they contain. The distribution of species within the ecosystem therefore has two characteristics: species richness or diversity, which simply refers to the number of species, and equitability or evenness, which measures the allotment or distribution of individuals among the different species. The greater the number of species counted, the higher is the species diversity. The more even the distribution of individuals among the resident species, the higher is the equitability. The concepts of species diversity and equitability have been integrated into a single concept of heterogeneity which reflects the relative abundance of species in the community (Peet, 1974). Thus

f-----

I

/invading

---jT]-------------;

; VI I I

I 1 invading species(

I

Figure 2.4. The cyclic type of community change and its’fourphases: (1) establishment; (2) build-up; (3) maturation; and (4) degeneration. (After Watt, 1947).


heterogeneity is higher in the ecosystem whenever there are more species and when the species are equally abundant. Characteristically, mature or stable ecosystems have a few species that are common in terms of the large number of individuals or biomass and numerous rare species are the incidentals.

Species diversity has been used extensively in comparing communities or habitats within a given region or even the biosphere. Species diversity gradients do exist among different ecosystems: tropical environments support more species of plants and animals in all taxonomic groups than temperate and polar regions do. A number of factors have been proposed to explain the differences in the species diversity of the different ecosystems here on earth (Smith, 1980; Krebs, 1985). Time, on an evolutionary or ecological scale, as a factor would allow more speciation and population dispersal to occur. Hence, older or mature ecosystems are expected to have a higher species diversity. Spatial heterogeneity would also increase species diversity through the greater number and kinds of favourable habitats available for living organisms. Environmental or climatic stability is another factor that may enhance species diversity in the ecosystem. Ecosystems with high productivity can also accommodate more species. Biological competition also enhances species diversity in favourable environments where competing species become more specialized in the use of resources. Predation influences diversity by maintaining low prey densities so as to reduce competition among prey populations. The interaction among these factors would determine species diversity in different ecosystems. Hence, between comparable ecosystems, tropical habitats would have a higher species diversity than temperate areas because they are older or more mature and more productive ecosystems with greater spatial heterogeneity and climatic stability. Furthermore, species competition and predation in the tropics occur at higher intensities.

The third aspect of the biological structure in the ecosystem deals with the relationships between species. Such relationships are aptly described in terms of the ecological niche concept which has in one context or another been equated with habitat, functional role(s), morphological traits, food habits of and even competition among species in the ecosystem. The niche concept, however, basically defines the precise conditions which a species needs to persist in the ecosystem. Hutchinson (1959) considered the niche as the total range of environmental conditions under which the organism lives and reproduces. According to Odum (1963) the niche is an organism’s position or status within the community as a result of the organism’s structural adaptations, physiological responses and behaviour. Reduced to a short but meaningful definition, the niche is simply the functional role of the species in the ecosystem. But before an organism can perform its function or role, it must first establish residence or its habitat. Hence, the ecological niche must also have the dimension of a habitat with its resources.

The fundamental niche is the maximum niche a species can occupy in the absence of competition from other species. In the presence of biological and environmental constraints, the fundamental niche gets reduced to a smaller niche called the realized niche. Avacant niche in the ecosystem is a role which is not filled and can thus be occupied by colonizing species. The breadth of an organism’s niche is measured by its range of tolerance for food, habitat and resources. Species exhibiting wide tolerance ranges would have wide niches while those with rather narrow tolerances occupy narrow niches. A species which can utilize a wide variety of food resources or inhabit areas with variable conditions would have a wider niche than one which uses only a few sources of food or dwell in sites where conditions are fairly stable. A niche overlap occurs when two or more organisms occupy the same or similar habitats or use the same food resource. Thus the idea of competition among species is closely related with the ecological niche concept. In most ecosystems, however, there are many species with diverse roles or wide

The Ecosystem 27

niches that enable them to specialize in their function so as to avoid direct competition with other species. The concept of competition will be discussed further in a later section.

Ecosystem Function

Interactions between the physical and biological structures of the ecosystem will largely determine its functioning. Ecosystem function refers to how it works as a processor of energy and nutrients. Hence, the functional framework of the ecosystem is usually described in terms of energy flow and nutrient cycles. Both energy flow and nutrient cycles are the primary determinants of ecosystem productivity. But before the ecosystem can function or produce, it must first get organized. The ecosystem contains several organisms which must relate and interact with one another in ways that would ensure their survival and persistence. Such relationships and interactions give rise to an organization that will efficiently and effectively participate in the flow of energy and nutrients in the ecosystem.

Organization

The ecosystem can be organized by three ecological processes: competition; predation; and symbiosis. These activities describe the manner in which different biotic forms obtain food and nutrients from their habitat. Organisms utilizing the same or similar environmental resources are most likely to compete for space and nutrients and the more efficient of competitive ones will grow and reproduce better. Intraspecific competition occurs among individuals of the same species while interspecific competition involves individuals belonging to different species. Competition among biotic units could thus control the density and abundance of species in the ecosystem.

Predation occurs when the members of one species eat or consume individuals of another species. It is a very critical factor in the regulation of population sizes in the ecosystem: the removal of predators will cause a population explosion of the prey to the extent of starvation, or excessive predation may eliminate the prey to the extent that predators may starve. Through ecological tune, the relationship between predators and prey may lead to their mutual benefit: predators acquire food and the prey avoid overcrowding. Predation could thus organize the ecosystem along feeding patterns.

In the course of evolution, some species of plants and animals, had the opportunity to establish intimate and beneficial associations with other species through the development of closely related niches. An association in which two organisms belong to different species is known as symbiosis. Although symbiotic relationships widely occur in the animal kingdom, these are rather loose and not as intimate or obligatory as those observed in the plant kingdom where many species have become so specialized for a symbiotic life that they can no longer exist by themselves. Two very common cases of plant symbiosis which are critical to the functioning of ecosystems are the mycorrhiza and root nodules.

Mycorrhiza are associations between fungi and roots in the soil. The fungi facilitate nutrient uptake by the roots and in return obtain carbohydrates from the root’s food supply. Such a relationship indeed benefits both organisms. Mycorrhizal associations are very common among trees. A number of trees will not grow well without mycorrhiza. When the fungal mass forms a sheath surrounding the root tips, it is referred to as ectotrophic mycorrhiza. The mycorrhiza may also be termed endotrophic when the fungal mass penetrates the root as well as surrounds it. Roots with mycorrhiza are shorter and more branched than other roots.


Symbiotic associations between some bacteria and roots form root nodules which are highly capable of nitrogen fixation. The root provides food and shelter for the bacteria while the bacteria fix atmospheric nitrogen into nitrate for the root. Root nodules are very common among legumes. Atmospheric nitrogen fixation is a very important component of the nitrogen cycle.

The transfer of food from the producers through herbivores to carnivores is termed as a food chain. When food chains are hooked together or integrated in the ecosystem, they constitute complex food webs. Food chains and webs that characterize the flow of food energy lead to the trophic organization of the ecosystem. Four trophic levels are quite evident in any trophic organization. The first trophic level is made up of green plants which are referred to as producers. To the second trophic level belong the herbivores and plant parasites which are primary consumers. The third trophic level consists of carnivores and animal parasites which act as secondary consumers. Higher carnivores, including omnivores and animal hyperparasites, constitute the fourth trophic level as tertiary consumers. The assignment or classification of organisms into trophic levels is based on function and not on taxonomy of species. Within a trophic level there are species which may exploit the same food resource from a lower level. These species constitute a guild. Hence the trophic organization of the ecosystem may also be described in terms of herbivore guilds or carnivore guilds.

Another important component of ecosystem organization is ecological dominance within each trophic level or guild. Dominant species can be easily recognized by their abundance in numbers or high biomass. Basically, dominance is attained through competitive superiority. Thus canopy trees are the dominant vegetation in forest ecosystems since they are more efficient in harvesting light and extracting moisture and nutrients from the soil than the sub-canopy or ground species. Their immense heights, spreading foliage and deep root systems enable them to form more biomass.

Productivity

Inasmuch as there is a separate chapter on energy flow and nutrient cycles, this section will consider the two functional aspects of the ecosystem in terms of the concept of ecological productivity. As mentioned earlier, the flows of nutrients and energy basically determine ecosystem productivity and will be discussed in more detail in another chapter.

The flow of energy and the recycling of essential nutrients are both vital for the growth of living organisms and the functioning of the ecosystem. Both processes are deemed crucial in the production of new organic material or biomass. Biological productivity refers to the rate of production of biomass. At the ecosystem level, ecological productivity would include biological productivities at each trophic level. The standing crop in the ecosystem refers to the amount of biomass present at one point in time and should not be interchanged with productivity.

There are two basic types of productivity in the ecosystem: primary and secondary productivity. The first type refers to the production of new organic matter at the different heterotroph levels. Each basic type can be divided further into gross and net productivity. Gross productivity is the total amount of organic matter produced while net productivity is the amount of organic matter left after some has been used in respiration. Hence, gross primary productivity refers to the total amount of organic matter or carbohydrates produced in plants during photosynthesis and net primary productivity to the amount of carbohydrates left after some has been used in respiration.

The Ecosystem 29

.

.

Gross Primary Productivity =

Net Primary Productivity =

Total Amount of Carbohydrates Produced in Photosynthesis

Gross Primary Productivity - Respiration Loss

Gross secondary productivity is thus the total amount of organic matter assimilated as food by animals in the different heterotrophic levels while net secondary productivity is the amount left after some of the assimilated food has been used in respiration.

Gross Secondary Productivity = Total Organic Matter Consumed as Food

Net Secondary Productivity = Gross Secondary Productivity - Respiration Loss

Since productivity is the rate of production of organic matter, it has a time-period component and all its units include three basic measurements: a measure of biomass (e.g. dry weight, numbers of individuals, kilocalories); a measure of area (e.g. square meter, hectare); and a measure of time (e.g. day, month, year). The most frequently used unit of measurement, however, is dry weight per square metre per day. Primary and secondary production in relation to energy flow in the ecosystem will be discussed in more detail later.

Measurements of productivity in the earth’s different natural ecosystems have revealed very variable and very low rates of gross primary productivity, as shown in Table 2.4. Some ecosystems, like the deserts and open oceans, are relatively unproductive while others, like estuaries and coral reefs, are relatively fertile. These productivity levels can be grouped into three categories of magnitude: the relatively unproductive with productivity levels below 0.1 gram/square metre/day (g/m2/day); the moderately productive where productivity lies between 1 and 10 g/m2/day; and the very productive with productivity levels of 10 to 20 g/m2/day.

Based on the foregoing data (Table 2.4) on the productivity levels of the different ecosystems in the biosphere, there are certain general patterns in the world distribution of primary production.

Table 2.4. World distribution ofprimaryproduction in the different ecosystems (after Odum, 1971).

Ecosystems Gross Primary Productivity (gram/square meter/day)

Deserts less than 0.5

Dry Grasslands, Mountain Forests, Deep Lakes 0.5 - 3.0

Moist Temperate Forests, Shallow Lakes, Moist Grasslands

3 -10

Estuaries, Springs, Coral Reefs, Tropical Forests

Continental Shelf Waters of Seas and Oceans

Deep Ocean

10-25

0.5 - 3.0

less than 1.0


A very large portion of the earth’s surface is unproductive either because of lack of moisture as in the vast deserts or lack of nutrients as in the oceans and seas which constitute around 70 per cent of the earth’s cover. Despite the much greater area of marine ecosystems, their productivity is much lower than that of terrestrial ecosystems due to a number of causes, notably: marine waters absorb and reflect more solar-radiation than the atmosphere of terrestrial habitats; deficient levels of essential nutrients such as nitrogen and phosphorus in the surface waters where photosynthetic organisms are found; and the high respiration rates of such microscopic producers. The most productive ecosystems such as estuaries and swamps are relatively open areas which receive and trap nutrients from adjacent habitats.

In Summary

Ecology seeks explanations for the relative abundance of living forms in nature through the study of the relationships and interactions between living things and their physical, chemical and biological environments. Such relationships lead to the integration of individuals, species or populations and biotic communities with their environment and constitute an ecological system or ecosystem. Since natural ecosystems are basically open, there are material and energy inputs and outputs as materials are exchanged and processed through energy flows during the interaction between the biotic and abiotic components in the ecosystem.

A natural ecosystem has a characteristic structure and function. Its structure is defined in terms of physical and biological features. An ecosystem’s physical structure has three components: growth or life forms, vertical stratification and seasons. Its biological structure involves species composition and abundance, temporal or successional changes and relationships between species. Both structural dimensions strongly influence the functioning of the ecosystem.

Ecosystem function refers to how biotic units are organized and process energy and nutrients through species interactions. Trophic organization involves the assignment of biotic units into different trophic levels of the food chains and food webs in the ecosystem as well as ecological dominance among species through numbers or biomass. The flow of energy and cycling of essential nutrients are reflected in the productivity of the ecosystem. Measurements of the productivity of the earth’s different ecosystems have revealed wide variations: from the relatively unproductive deserts and deep oceans to the fertile tropical forests, estuaries and coral reefs. Available moisture, nutrients and light are the primary determinants in the distribution of primary productivity among the earth’s different ecosystems.

The Ecosystem 31

References

Arnon, D.I. and P.R. Stout. 1939. The essentiality of certain elements in minute quantityforplants with special reference to copper. Plant Physiology 14:371-375.

Delwiche, C.C. 1967. Energy relationships in soil biochemistry. In: A.D. McLaren and G.H. Peterson (eds). Soil Biochemistry. Marcel Dekker, Inc. New York. pp. 173-193.

Edwards, CA. and G.W. Heath. 1963. The role of soil animals in breakdown of leaf material. In: J. Doeksen and J. van der Drift (eds.). Soil Oqanisms. North-Holland Publishing Co., Amsterdam.

Emberlin, J.C. 1983. Introduction to Ecology. Macdonald and Evans Ltd., Plymouth, Great Britain.

Etherington, J.R. 1978. Plant Physiological Ecology. Edward Arnold (Publishers) Limited, London.

Gates, D.M. 1965. Radiant ener-gy, its receipt and disposal. Meteorological Monographs 6:1-26.

Hall, D.O. and K.K. Rao. 1977. Photosynthesis. Edward Arnold, London. (Second Edition).

Hutchinson, G.E. 1970. The Biosphere. Scientific American 223:45-53.

Jones, G. 1979. Vegetation Productivity: Topics in Applied Geography. Longman, London.

Lindeman, R.L. 1942. The trophic-dynamic aspect of ecology. Ecology 23:399-418.

Odum, H.T. 1956. Eff rciencies, size of organisms, and community structure. Ecology 37:592-597.

Odum, H.T. 1957. Tropic structure and productivity of Silver Springs, Florida. Ecological Monographs 27:55-l 12.

Odum, E.P. 1960. Or-gcnicproduction and turnover in old-field succession. Ecology 41:34-49.

Odum, E.P. 1963. Ecology. Holt, Reinhart and Winston, New York.

Raunkaier, C. 1934. The Life Form of Plants and Statistical Plant Geography. Clarendon Press, Oxford.

Rowe, J.S. 1961. The level-of-integration concept and ecology. Ecology 42:420-427.

Smith, L.S. 1980. Ecology and Field Biology. Harper and Row, Publishers, New York.

Tansley, A.G. 1935. The use and abuse of vegetational concepts and terms. Ecology 16:284-307.

Watt, A.S. 1947. Pattern andprocess in theplant community. Journal of Ecology 35:1-22.

Whittaker, R.H. 1975. Communities and Ecosystems. 2nd ed. Macmillan, New York.

Chapter 3

Energy Flow in the Atmosphere*

The primary source of energy of the earth is the sun which continuously radiates electromagnetic energy in space. The earth intercepts a very small fraction (one part in 2 billion) of the total energy emitted by the sun. This energy is the key to all atmospheric processes that we observe. In order to study the flow of this energy in the atmosphere, we need to consider the nature of the atmosphere - its composition and structure.

Composition of the Atmosphere

The atmosphere is a mixture of gases that envelops the earth. It is highly compressible so that its lower layers are very much more dense than those above. Although the atmosphere is composed of a number of gases, five of them - nitrogen, oxygen, argon, carbon dioxide and water vapour - make up 99.99 per cent of it by volume below 90 km. The average composition of dry air is given in Table 3.1

Table 3.1. Average composition of the dry atmosphere below 25 km

* Prepared. by Dr. Jorge de las Alas, Chairman, Dept. of Meteorology and Oceanography, University of the ’ Philippines, Diliman, Quezon City.

Part/ - The Knowledge Base 34

The lighter gases (hydrogen and helium especially) might be expected to become more abundant in the upper atmosphere, but large-scale turbulent mixing of the atmosphere prevents such diffusive separation even at heights of many tens of kilometres above the surface. The height variations which do occur are related to the source-locations of the two major non-per- manent gases - water vapour and ozone. Since both absorb some solar and terrestrial radiation the heat budget and vertical temperature structure of the atmosphere are considerably affected by the distribution of these two gases.

Water vapour comprises up to 4 per cent of the atmosphere by volume near the surface, but is almost absent above 10 to 12 km. It is supplied to the atmosphere by evaporation from surface water or by transpiration from plants and is transferred upwards by atmospheric turbulence. Turbulence is most effective below about 10 km and as the maximum possible water vapour density of cold air is anyway very low, there is little water vapour in the upper layers of the atmosphere.

Ozone is concentrated mainly between 15 to 35 km. The upper layers of the atmosphere are irradiated by ultraviolet radiation from the sun which causes the break-up of oxygen molecules in the layer between about 80 to 100 km. These separated atoms may then individually combine with other oxygen molecules to create ozone in a three-body collision in the presence of a third atom or molecule. Such three-body collisions are rare at 80 to 100 km because of the very low density of the atmosphere, while below about 35 km most of the incoming ultraviolet radiation has already been absorbed at higher levels. Therefore, ozone is mainly formed between 30 and 60 km where collisions between atomic oxygen and molecular oxygen are more likely. Ozone itself is unstable and it may be destroyed either by collisions with mono-atomic oxygen to recreate oxygen or by the action of radiation on it.

The constant metamorphosis of oxygen to ozone and from ozone back to oxygen by photochemical processes maintains an approximate equilibrium above about 40 km, but the ozone mixing ratio is a maximum at about 35 km, whereas maximum ozone density occurs lower down between 20 and 25 km.

The quantities of carbon dioxide and ozone in the atmosphere may be subject to variations over a long time-period and these are of special significance because of their possible effect on the radiation budget.

Carbon dioxide enters the atmosphere mainly by the action of living organisms on land and in the ocean. The decay of organic elements in the soil and the burning of fossil fuels are additional sources. It is obvious that if this production were not countered in some way the total quantity of carbon dioxide would steadily increase. A balance, or dynamic equilibrium, is maintained primarily by photosynthesis which removes approximately 3 per cent of the world’s total carbon dioxide annually. In the oceans the carbon dioxide ultimately goes to produce carbonate of lime, partly in the form of shells and the skeletons of marine creatures. On land the dead matter becomes humus which may subsequently form a fossil fuel.

Nature of Solar Radiation

The prime source of the energy injected into our atmosphere is the sun, which is continually shedding part of its mass by radiating electromagnetic energy waves and high speed particles into space. This constant emission, termed insolation, is important because it represents in the long run almost all the energy available to the earth (except for a small amount emanating from the radioactive decay of earth minerals). The amount of insolation received by the earth,

Energy Flow in the Atmosphere 35

assuming for the moment that there is no interference from the atmosphere, is affected by four factors, namely: solar output; distance from the sun; altitude of the sun; and length of day.

Solar Output

Of the total energy sent out into space the earth intercepts only some two thousand millionths, equivalent to a power of 1.8 x 1014 kW. The energy received on a surface normal to a solar beam is about 1.396 kW/m2; this is termed the solar constant. The small proportion of solar energy available to the earth is reflected in the difference between the surface temperatures of the sun and earth; the temperature at the surface of the former is believed to be about 6000 K, whereas the mean temperature of the earth’s atmosphere is only about 250 K and that of the earth’s surface is only 283 K

Solar radiation is very intense and is mainly short wave between about 0.2 micron and 4.0 microns, with a peak in the middle part of the spectrum; whereas the much weaker terrestrial radiation has a peak intensity of about 10 microns and a range of about 4 microns to 100 microns.

Distance from the Sun

The ever changing distance of the earth from the sun produces more frequent variations in our receipt of solar energy. Owing to the eccentricity of the earth’s orbit around the sun, the receipt of solar energy on a surface normal to the beam is 7 per cent more on 3 January at the perihelion than on 4 July at the aphelion. In theory (that is, discounting the interposition of the atmosphere and the difference in degree of conductivity between large land and sea masses) this difference should produce an increase in the effective January world surface temperatures of about 4 degrees C over those of July. It should also make northern hemisphere winters warmer than those in the southern, and southern hemisphere summers warmer than those in the northern. In practice, atmospheric heat circulation and the elfects of continentality substantially mask the global tendency and the actual seasonal contrast between the hemispheres is reversed.

Altitude of the Sun

The altitude of the sun (i.e., the angle between its rays and a tangent to the earth’s surface at the point of observation) also affects the amount of insolation received at the surface of the earth. The greater the sun’s altitude the more concentrated is the radiation intensity per unit area at the earth’s surface. There are, in addition, important variations with solar altitude of the proportion of radiation reflected by the surface, particularly in the case of a water surface. The principal factors which determine the sun’s altitude are, of course, the latitude of the site, the time of day and the season.

Effect of the Atmosphere

Solar radiation is virtually all in the short wave-length range, less than 4 microns. About 15 per cent of the incoming energy is absorbed directly by ozone and water vapour. Ozone absorbs all ultraviolet radiation below 0.29 micron and water vapour absorbs to a lesser extent in several narrow bands between about 0.9 micron to 2.1 microns. Nearly 40 per cent is immediately reflected back into space from the atmosphere, clouds and the earth’s surface, leaving only about 60 per cent to actually heat the earth and its atmosphere. Of this, the greater

_. ._... -.--II


part eventually heats the atmosphere, but most of the heat is received secondhand by the atmospherevia the earth’s surface, primarily in the form of sensible and latent heat. The ultimate retention of this energy by the atmosphere is of prime importance, because if it did not occur the average temperature of the earth’s surface would fall by some 40 degrees C, making most life obviously impossible. The earth itself directly absorbs 27 per cent of the incoming short waves (together with an indirect 20 per cent of energy reflected down or conducted from the atmosphere) and reradiates them outwards as long (infra-red) waves of greater than 3 microns. Much of this reradiated long-wave energy can be absorbed by the water vapour, carbon dioxide and ozone in the atmosphere, the rest escaping through radiation windows back into outer space. Of an assumed 100 per cent of energy available at the top of the atmosphere, only 47 per cent is absorbed by the earth’s surface.

Effect of Cloud Cover

Cloud cover can, if it is thick and complete enough, form a significant barrier to the penetration of insolation. How much insolation is actually reflected depends on the amount of cloud cover and its thickness.

The effect of a cloud cover also operates in reverse, since it serves to retain much of the heat that would otherwise be lost from the earth by radiation throughout the day and night. This largely negative role of cloud means that their presence appreciably lessens the daily temperature range by preventing high maxima by day and low minima by night. As well as interfering with the transmission of radiation, clouds act as temporary thermal reservoirs for they absorb a certain proportion of the energy which they intercept.

Effect of Latitude

Different parts of the earth’s surface receive different amounts of insolation. The time of the year is one factor controlling this, more insolation being received in summer than in winter because of the higher altitude of the sun and the longer days. Latitude is avery important control over insolation because the geographical situation of a region will determine both the duration of daylight and the distance travelled through the atmosphere by the oblique rays from the sun.

Aspecial feature of the latitudinal receipt of insolation is that the maximum temperatures experienced at the earth’s surface do not occur at the equator, as one might expect, but at the tropics. A number of factors need to be taken into account. The apparent migration of the vertical sun is relatively rapid during its passage over the equator but its rate slows down as it reaches the tropics. Between 6deg N and 6 deg S the sun’s rays remain almost vertically overhead for only 30 days during periods of spring and autumn equinoxes, allowing little time for any large build-up of surface heat and high temperatures. On the other hand, between 17.5 deg and 23.5 deg latitude the sun’s rays shine down almost vertically for 86 consecutive days during the period of the solstice. This longer sustained period, combined with the fact that the tropics experience longer days than at the equator, makes the maximum zones of heating occur nearer the tropics than the equator.

Effect of Land and Sea

Another important control on the effect of incoming solar radiation stems from the different ways in which land and sea are able to profit from it. Whereas water has a tendency to store the heat it receives, land, in contrast, quickly returns it to the atmosphere.


A large portion of insolation is reflected back into the atmosphere without heating the earth’s surface at all. The proportion of incident radiation that is reflected is termed the albedo or reflection coefficient. It depends upon the type of surface. The solar energy absorbed at the surface is determined from measurements of incident radiation and albedo. A snow surface will absorb only about 15 per cent of the incident radiation, whereas for the sea the figure generally exceeds 90 per cent. The ability of the sea to absorb the heat received also depends upon its transparency. As much as 20 per cent of the radiation penetrates as far down as 9 metres. However, the heat absorbed by the sea is carried down to considerable depths by the turbulent mixing of water masses by the action of waves and currents.

Air is an extremely poor conductor and for this reason a loose, sandy soil surface heats up rapidly by day, as the heat is not conducted away. Increased soil moisture tends to raise the conductivity by filling the soil pores, but too much moisture increases the soil’s heat capacity, thereby reducing the temperature response.

The different heating qualities of land and water are also partly to be accounted for by their different specific heats. The specific heat of a substance can be represented by the number of thermal units required to raise a unit mass of it through one degree. The specific heat of water is much greater than that of most other common substances, and thus water must absorb five times as much heat energy to raise its temperature by the same amount as a comparable mass of dry soil. If unit volumes of water and soil are considered the heat capacity of the water exceeds that of the soil approximately twofold. When water is cooled, the situation is reversed, for then a large quantity of heat is released. Similarly, evaporation of sea water causes a large heat expenditure because a great amount of energy is needed to evaporate even a small quantity of water.

These differences between land and sea help to produce what is termed as continentality. Continentality implies, firstly, that a land surface heats and cools much quicker that that of an ocean. Over the land the lag between maximum and minimum periods of insolation and the maximum and minimum surface temperatures is only one month, but over the ocean and at coastal stations the lag is as much as two months. Secondly, the annual and diurnal ranges of temperature are greater in continental than in coastal locations. The third effect of continentality results from the global distribution of the land masses. The small sea area of the northern hemisphere causes the northern hemisphere summer to be warmer but its winters colder on the average than those of the southern hemisphere. Heat storage in the oceans causes them to be warmer in winter and cooler in summer than land in the same latitude, although ocean currents give rise to some local departures from this rule.

Heat Budget of the Earth

The radiation from the sun reaches the earth predominantly in the form of short waves and leaves as long waves. Of all the incoming radiation, regarded for convenience as 100 units: 2 units are absorbed in the stratosphere, by ozone mainly, and 15 units are absorbed in the troposphere by ozone, water vapour and water droplets in clouds; 23 units are reflected back into space from clouds and 7 units from the earth’s surface; while a further 6 units are scattered upwards by air molecules, water drops and dust particles. The remaining 47 units reach the earth either directly (31 units) or as diffuse radiation transmitted via clouds or by downward scattering (16 units). The scattering effect of air molecules on the visible wavelengths of radiation is greatest at short wavelengths, and hence the sky light appears blue in colour.


The pattern of outgoing terrestrial radiation is quite different. The black-body radiation, assuming a mean surface temperature of 288 K, is equivalent to 98 units of long-wave (infra-red) radiation - but this does not imply that the surface undergoes a net loss of radiation, as the figures for total balance show. The great majority of this is absorbed in the atmosphere chiefly by carbon dioxide, water vapour and cloud droplets, although 7 units are lost through radiation windows - bands in the wavelength spectrum where little or no absorption takes place. The troposphere reradiates 78 units back to the surface and 57 units to space.

It is worth emphasizing that long-wave radiation is not merely terrestrial. The atmosphere itself radiates to space, and clouds are particularly important since they act as black bodies. At the surface net radiation is 27 units. This surplus is conveyed to the atmosphere by the turbulent transfer of sensible heat (5 units) and latent heat (22 units). There is also a flux of heat to the ground, but for annual averages this is approximately zero.

The annual and diurnal variations of temperature are directly related to the local radiation budget. The sum of the net upward and downward radiation transfers at the surface is, in most latitudes, positive between about one hour after sunrise to a few hours before sunset. There are marked latitudinal variations in the diurnal and annual ranges of temperature. Broadly, the annual range is a maximum in higher latitudes, with extreme values about 65 deg N related to the effects of continentality in Asia and North America. The diurnal range reaches a maximum at the tropics over land areas, but it is in the equatorial zone that the diurnal variation of heating and cooling exceeds the annual one. This is of course related to the small seasonal change in solar elevation angle at the equator.

Atmospheric Energy and Horizontal Heat Transport

So far, the gases and other constituents which make up our atmosphere as well as the earth’s heat budget have been described. Two forms of energy have been referred to - internal (or heat) energy due to the motion of individual air molecules and latent energy which is released by condensation of water vapour. Two other forms of energy are important - geopotential energy due to gravity and height above the surface and kinetic energy associated with air motion.

Geopotential and internal energy are interrelated since the addition of heat to an air column not only increases its internal energy, but adds to its geopotential as a result of the vertical expansion of the air column. In a column extending to the top of the atmosphere the geopotential is approximately 40 per cent of the internal energy. These two are therefore usually considered together and termed the total potential energy (PE). For the whole atmosphere, potential energy is in the order of 1O24 joules while kinetic energy is in the order of 1020 joules.

It is apparent that the receipt of heat energy is very unequal geographically and that this must lead to great lateral transfers of energy across the surface of the earth. The amounts of energy received at different latitudes vary substantially, the equator on the average receiving 2.5 times as much annual solar energy as the poles. Clearly, if this process was not modified in some way the variations in receipt would cause a massive accumulation of heat within the tropics (associated with gradual increases of temperature) and a corresponding deficiency at the poles. Yet this does not seem to happen, and the earth as a whole is roughly in a state of thermal equilibrium in so far as no one region is obviously gaining heat at the expense of another.


The Horizontal Transport of Heat

If the net radiation for the whole earth-atmosphere system is calculated, it is found that there is a positive budget (energy surplus) between 35 deg S and 40 deg N. As the tropics do not get progressively hotter or the high latitudes colder, a redistribution of world heat energy must constantly occur, taking the form of a continuous movement of energy from the tropics to the poles. In this way the tropics shed their excess heat thus the poles are not allowed to reach extremes of cold. If there were no meridional interchange of heat, a radiation balance at each latitude would only be achieved if the equator were 14 deg C warmer and the north pole 25 deg C colder than now. This poleward heat transport takes place within the atmosphere and oceans, and it is estimated that the former accounts for approximately 80 per cent of the required total. The horizontal transport (advection of heat) occurs in the form of both latent heat (that is, water vapour that subsequently condenses) and sensible heat (that is, warm air masses). It varies in intensity according to season and latitude.

The intensity of the poleward energy flow is closely related to the meridional (north-south) temperature gradient. In winter this temperature gradient is at a maximum and in consequence the hemispheric air circulation is most intense.

Chapter 4

Energy Flow and Nutrient Cycles in the Biosphere*

“All things go under the eatlh and reenter the game.” Paul Valery (1871-l 945)

The biosphere is the thin layer of life on the surface of the earth that has existed and evolved for billions of years. It is also called the ecosphere and includes all of the earth’s living organisms interacting with the physical environment as a whole. These interactions maintain a steady-state system in the ecosphere that is intermediate in the flow of energy between the high energy input of the sun and the thermal sink of space. This steady-state system enables organisms, species or populations, biotic communities and even ecosystems to successfully integrate with and adapt to their environments. The ability of biological systems to integrate with their surroundings is governed by energy flows and the cycling of materials essential to life. All living forms, i.e., producers, consumers and decomposers, need energy and materials to live and persist as individuals or members of a population or community. Production consumption and decomposition in the biosphere are all energy and matter based.

The Nature of Energy

Energy is broadly defined as the capacity to do work. Among its various forms or states, those of greatest importance to living things and the biosphere are mechanical, chemical, solar or light and heat energy.

Mechanical energy assumes two forms: kinetic and potential. Kinetic or free energy is described as useful energy which a body possesses by virtue of its motion; it is measured by the amount of work needed to bring the body to rest. Potential energy is basically stored energy until its conversion into the kinetic form when it becomes available to perform work involving movement. Chemical energy is a form of stored or potential energy in chemical compounds which yield useful energy when atoms are rearranged. The burning of food during respiration by living organisms releases energy which is most useful for biological work such as transport and biosynthesis. Solar or light energy is radiant energy from the sun, avast incandescent sphere

* Prepared by Dr. Reynaldo A. Tabbada, Professor, Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City.

_- -_.---. ..-. - ..--I_.- .- -__


of gas, which releases energy by the nuclear transmutation of hydrogen atoms to helium. Solar radiation is energy in the form of electromagnetic waves involving the rhythmic exchange between kinetic and potential energy. Heat energy results from the random movement of molecules and is released when all other forms of energy are transformed and work is performed. All biological work, notably growth and reproduction, represent energy transformation and ultimately involve heat production.

Energy and Life

Living organisms exploit energy sources of the biosphere to survive, grow and reproduce. A continuous input of new energy is needed to balance energy losses from biological activities. The energy utilized by living things comes from two sources: chemical potential energy derived from organic or inorganic substances and light energy obtained from the visible region of the solar electromagnetic radiation. The energy exploitation schemes and processes in the biosphere are presented in Fig. 4.1. As described by Etherington (1978) organisms that exploit and utilize light energy in the formation of carbohydrates or food are called photosynthesizers, of which there are two distinct groups: the photolithotrophs which utilize carbon dioxide and simple inorganic substances like water and hydrogen sulphide and the photo organotrophs which use carbon dioxide and organic molecules as raw materials. Organisms that exploit the potential energy of chemical substrates instead of light energy are termed chemosynthesizers, of which there are also two distinct kinds: the chemolithotrophs which utilize the energy released from the oxidation of simple inorganic molecules for the synthesis of carbohydrates, and the chemo organotrophs which obtain their energy requirements from the oxidation and breakdown of organic molecules. Based on their source of food or organic metabohtes, there are two main groups of living organisms in the biosphere: the heterotrophs which absorb or obtain organic food from their environment and the autotrophs whcih can make their own tool by photosynthesis or chemeosynthesis. The bulk, if not practically all, of the energy Bow in the biosphere at present is initiated by the photolithothrops which also account for practically all of the available organic metabolites.

Nutrients and Life

An elemental analysis of the chemical composition of living organisms would readily show that life is simply an elaboration of the chemical environment: naturally occurring elements have been arranged in specific combinations and configurations into simple and complex molecules that make up the body of an organism. Outside of the organism, these chemical elements are an abiotic component of the environment but as components of the chemistry of a living organism they are considered part of the biotic component of the ecosystem.

Of the 92 elements known to occur in nature, only about a third or around 30 have been demonstrated to be essential to living organisms. Essential nutrients have been studied more extensively in green plants than in animals or heterotrophs because the latter group obtain their food directly from the former in the form of preformed organic metabolites. Hence, it is the producers in the biosphere which must extract these essential elements from the environment. For an element to be considered as essential to plant life, its absence or inadequacy will lead to the non-completion of the life cycle since the element is presumed to perform a specific vital function(s) which no other element can perform (Arnon and Stout, 1939). There are two main groups of essential nutrients: the macronutrients, which are required in relatively large quantities and involved in the synthesis of living matter or protoplasm, and the micronutrients which

Energy Now and Nutrient Cycles 43

Y a 3

0 co

> (3 a W

z

w

ORGANIC METABOLITE SOURCE

ABSORPTION FROM THE INTERNAL SYNTHESIS ENVIRONMENT

PHOTOLITHOTROPHS PHOTOORGANOTROPHS

H2S, H20 Other H sources

2H + 2e-

CARBOHYDRATES

- Light Energy

s 02, Other by products

Light 1 2

2H + 2e-

1

Organic by-product

CARBOHYDRATES

Inorganic Molecules

Inorganic by-products

9 CARBOHYDRATES

Organic Substance

Chemical Energy

co2

H20

I- I

I. AUTOTROPHS I

1

HETEROTROPHS I

Figure 4.1. Energy exploitation by living organisms in the biosphere. (after Etherington, 1978)

Pat-t I - The Knowledge Base 44

are needed in very minute amounts. The major macronutrients are carbon, hydrogen, oxygen and nitrogen which together account for about 95 per cent of the dry weight of the protoplasm. Phosphorus, sulphur, calcium, magnesium and potassium are the other macronutrients. Around ten micronutrients are needed by plants: iron, manganese, copper, zinc, boron, molybdenum, chlorine, cobalt, sodium and vanadium.

Although plants are capable of absorbing all the naturally occurring elements, only carbon, hydrogen and oxygen are usually found in very large quantities in the protoplasm. This is not surprising since hydrogen and oxygen together in the form of water account for much of the total fresh weight of a living organism. Hence, most other elements, including the other macronutrients and especially the micronutrients, occur only in small amounts in the protoplasm. The macronutrients carbon, hydrogen and oxygen are the major components of lipids and carbohydrates and together with nitrogen and sulphur form proteins. These macro- molecules are the chemical basis of cellular structure in living organisms. Phosphorus together with nitrogen bases and sugars provide the building blocks of the genetic material. The other macronutrients are also involved in the formation of cellular structure: calcium in cell walls and magnesium in chlorophyll molecules. Unlike the macronutrients which are fixed in cellular structures and hence are required in larger amounts, the micronutrients are either incorporated into enzymes or act as enzyme co-factors or activators and hence are not used up in the formation of new protoplasm.

The nutrition of animals is quite distinct from that of plants; animals have more varied nutritional needs and different metabolic reactions. They cannot readily synthesize carbohydrates, lipids or proteins but must obtain these in a ready-made form from plants. The plant food they consume already contains both macro and micronutrients essential to life. Therefore, although the same essential nutrients circulate in both plants and animals, these elements pass from the first trophic level to the higher trophic levels of the food web or chain as preformed organic food rather than as simple substances.

Energy Flows

The ultimate source of energy in the biosphere is solar radiation. Since only a tiny fraction of this energy source, around 0.05 per cent of that which strikes the earth (Delwiche, 1967) actually flows through and powers the biosphere, it is quite important, if not interesting enough, to understand the fate of solar radiation reaching the earth and its atmosphere. Likewise, since all forms of energy are interconvertible and such conversions are governed by exchange laws, the flow of energy in the biosphere can be appreciated better if the laws governing the transformation of energy are fairly understood. And inasmuch as ecological productivity, which is actually the product of energy flow and nutrient cycles, has been discussed in the paper on ecosystem structure and function, this section will consider energy flow in the biosphere basically in terms of energy transformations and food webs and chains.

Solar Energy Balance of the Biosphere

Solar energy that penetrates the earth’s atmosphere and eventually strikes-the biosphere has wavelengths ranging from 0.1 to 10.0 Urn. About 4 per cent of incoming solar radiation is ultraviolet with wavelengths of 0.1 to 0.4 Urn. Approximately 44 per cent is visible light of 0.4 to 0.7 urn wavelengths. The remaining 52 per cent is infrared or long-wave radiation with wavelengths of 0.7 to 10.0 Urn.


The fate or main pathways of incoming solar radiation is reflected in the global energy balance as summarized in Fig. 4.2. Short-wave radiation from the sun (1) enters the earth’s atmosphere (2) and may be absorbed (3) to cause atmospheric heating (TO) or reflected and lost to space (4). The remaining portion is transmitted to the earth’s surface (5). The heated atmosphere may reradiate long-wave radiation on the earth’s surface (6). The absorption 01 short (5) and long-wave (6) radiation by the earth leads to surface heating, water evaporation and melting of ice. The earth in turn reradiates long-wave radiation to the atmosphere (7) or to outer space (8). Direct atmospheric heating (TO) together with conduction and convection of heat on the earth’s surface (9) provides all the energy needed to drive the circulation of atmospheric gases to ensure the continuity of the hydrological and gaseous cycles in the ecosphere. In spite of the continuous solar radiation reaching the earth, its temperature does not steadily rise because of the attainment of an equilibrium temperature at which the earth radiates as much energy to space as it receives from the sun. The radiated heat energy is long-wave infrared with wavelengths of 3.0-100 Urn.

. .

- short-wave radiation (0.3 to 3.0 urn) - - + long-wave radiation (3.0 to 100 urn)

To indicates increases or decreases in atmospheric temperature

Fipre 4.2. The solar enerD balance of Earth. (afier Ethehngton, 1978).


Laws Governing Energy Transformations

The flow of energy through the biosphere as well as the use of energy by living organisms is governed by the first two Laws of Thermodynamics. The first law recognizes the interconver- tibility of all forms of energy and states that energy may be transformed from one form to another but is neither created nor destroyed. Thus when a change occurs in a closed system wherein the amount of matter is constant but energy is able to enter or leave, an increase or decrease in the internal energy of the system (E), heat (Q) is lost or absorbed, and work (W) is performed:

AE = Q + W

decrease in internal heat released work done by energy of the system by the system the system

where the Greek letter A indicates a quantitative change.

Under this first Law of Thermodynamics is a more specific law which governs energy transformations in biological processes. This is the Law of Constant Heat Sums which states that the total amount of heat produced or absorbed is the same when a chemical reaction occurs directly or in one step. This is well illustrated in the biological process involving the oxidation of glucose to carbon dioxide and water by combustion or fermentation:

1. Direct Reaction (Combustion):

C&H1206 + 6 02 -- 6 Hz0 + 6 CO2 + 673 energy units (kilocalories)

2. Two-Stage Reaction (Fermentation):

a) C6H1206 -2 C2H5OH + 2 CO2 + 18 energy units (kilocalories)

b) 2 C~HSOH + 6 02 -. 6 Hz0 + 4 CO2 + 655 energy units (kilocalories)

a)+ b) : c&H1206 + 6 O2- 6 Hz0 + 6 CO;! + 673 energy units (kilocalories)

Hence, in either pathway the total amount of energy evolved is the same!

The second Law of Thermodynamics basically predicts how complete the conversions will be and states that processes involving transformations will not occur spontaneously unless there is a degradation of energy from a non-random to a random form. Simply, it means that no transformation of energy from one state to another is 100 per cent efficient. This is illustrated, for instance, when herbivores eat plants as food for body maintenance and growth: the animals will not be able to extract and use all the food energy in the plant tissues because during the conversion of plant protoplasm to animal protoplasm there will always be the release or wastage of energy as heat.

Energy Transformations: Primary Production

The first and second Laws of Thermodynamics thus determine the fate of the energy of solar radiation fixed as food by green plants. The fixed energy will flow through the biosphere in any of three possible pathways: it can be stored as chemical energy in plant or animal protoplasm; passed and transformed through food webs and chains; or escape from the ecosphere as heat.

Energy Flow and Nutrient Cycles 47

The energy content of solar radiation that enters the ecosphere is estimated at 2 calories per square centimetre per minute (a calorie refers to the amount of heat energy necessary to raise the temperature of one gram or one millilitre of water by 1 degree C at 15 degrees C), but this is reduced to about 1.34 calories when it reaches the earth’s surface due to atmospheric absorption or reHection (Gates, 1965). Solar radiation reaching the earth’s surface is further modified and decreased as it passes through cloud cover, water substrates and the vegetation of the biosphere. Hence, the daily energy input of sunlight which floods the biosphere ranges from 100 to 800 calories per 24-hour period. This then is the amount of available solar energy that can be fiied by green plants that will initiate the flow of energy in the biosphere.

Only a small portion of the light energy available to green plants is actually absorbed and transformed into food energy. The greater part is reflected by, transmitted through, or converted to heat by the plant body. On the average, merely 1 to 5 per cent of solar energy striking green leaves is trapped and used in the manufacture of food through a process known as photosynthesis. This process is the chemical basis of life, without which there is no biosphere or even life to speak of.

From a thermodynamic point of view, the photosynthetic process is simply the conversion of light energy into the chemical energy of food. The manufacture of carbohydrates during photosynthesis involves a number of chemical reactions catalyzed by several enzymes. It is usually summarized in equation form as:

GC02 + 6H?_O + Light Energy ----- C6H1206 + 6 02

from the from absorbed by sugar in released atmosphere the soil pigments, mainly plant cells to the (or respiration) chlorophyll, atmosphere

in the leaf (or used in respiration)

The light energy is primarily used in two processes: the synthesis of an energy-rich molecule, adenosine triphosphate (ATP), through a process known as photophosphorylation, and the breakdown or splitting of water into 02 and protons (2H + +2 electrons), with the former released into the atmosphere and the latter used in the formation of a potential reductant known as nicotinamide adenine diphosphoridine nucleotide (NADPH2). Hence the light energy absorbed by the green leaf is transformed into the chemical energy in ATP and NADPH2 which will be used in the synthesis of sugars by linking CO2 molecules together through a series of enzyme-mediated reactions, which, however, are beyond the scope of this paper.

The intensity of light basically determines the actual amount of energy available for photosynthesis. The capacity of plants to convert absorbed light energy into sugar is known as photosynthetic efficiency which is constrained by some environmental factors such as carbon dioxide and water availability as well as nutrient adequacy. In the biosphere, photosynthetic efficiency is, on a global average, only 8 per cent due to the inability of the photosynthetic apparatus to keep pace its capacity to convert light energy into chemical energy of sugars with the intensity of absorbed sunlight (Jones, 1979). The remaining 92 per cent is transformed into leaf sensible heat which may cause the evaporative loss of water vapour from leaf surfaces through microscopic openings in a process known as transpiration. Hence, the initial flow and conversion of energy in the biosphere is termed gross primary production and may be summarized as:


Solar energy Chemical energy

absorbed by = of sugars in plants leaf cells

+

Sensible

heat energy of leaves

(100 per cent) (8 per cent) (92 per cent)

The manufactured sugars can then be converted by the plant into energy-rich substances such as starch and fats which can be stored, as well as proteins and other chemical compounds through various metabolic pathways. These transformation reactions all require energy which is obtained primarily from the breakdown of some of the sugars produced in photosynthesis through a biological process known as respiration. This energy-producing breakdown process also involves a series of chemical reactions involving several enzymes and can be summarized as:

C6HlXh + 602 m- CO2 -I- Hz0 + Useful Energy

produced in photosynthesis

from the atmosphere (or photosynthesis)

released to the atmosphere (or used in photosynthesis)

in cells for metabolism growth and development

The actual proportion of the sugars produced in photosynthesis that is used up in respiration varies from 10 to 75 per cent, depending on a number of factors including the nature of the species, age and vigor of the plant. The amount of organic matter remaining after respiration in the plant is referred to as net primary production and represents the food available to consumers in the biosphere. Thus the transformation of solar energy to chemical energy by plants obeys the laws of thermodynamics in this manner:

Solar energy

assimilated = by plants

Chemical energy Heat energy

stored in tissues + of respiration of plants (25 to 90 per cent) (10 to 75 per cent) available to heterotrophs

The above equation shows the conversion of solar energy to chemical and heat energy and the conversion efficiency of solar to chemical energy to be less than 100 per cent.

Energy Transformations: Secondary Production

Net primary production represents the chemical energy stored in the tissues of the primary producers or green plants in the biosphere. This stored energy enters the second major pathway of energy flow through the food webs and heterotrophic levels that are involved in secondary production in the ecosystem.

The stored chemical energy in plant bodies does not accumulate through time because of consumption by heterotrophic organisms. Only in the absence of herbivores and omnivores would accumulation of organic plant matter occur. Presumably, a somewhat dynamic equilibrium exists between net primary production and the consumption of food by heterotrophs.


Heterotrophic organisms do not assimilate, or convert into living matter, all the food they ingest. Among herbivores, as much as 90 per cent of total food intake may be excreted as faecal wastes and among carnivores only 30 to 50 per cent of the flesh ingested is assimilated into living tissues (Phillipson, 1960). These energy transformations among heterotrophs likewise are in accordance with the laws of thermodynamics:

Chemical energy Chemical energy Chemical energy

(food) cortsunzed = assimilated + of faecal wastes by heterotrophs by heterotrophs produced by heterotrophs

(10 to 50 per cent) (50 to 90 per cent)

This equation of gross secondary production indicates no creation or destruction of energy, just transformation, and a less than 100 per cent efficiency in the assimilation of food energy into the heterotroph body.

As in plants, the food assimilated by heterotrophs can be stored as carbohydrates, fats and proteins or converted through various metabolic pathways into a variety of complex organic molecules. These metabolic conversions require energy and, just like plants, heterotrophs must also undergo respiration. Hence, the net secondary production in the biosphere may be summarized as:

Chemical energy Chemical energy Heat atergy

assimilated by = stored in the + -of respiration heterotrophs bodies of heterotrops

Again the above equation obeys the laws of thermodynamics: there is only conversion of chemical energy from the assimilated to the stored forms and the conversion is not 100 per cent or complete because of the release of heat during respiration.

In all heterotrophs, the efficiency of energy conversion is very low since respiration losses account for a great proportion of gross secondary production and hence may vary widely in the biosphere depending on the position of the heterotroph in the food chain: higher carnivores spend relatively more energy than lower carnivores or herbivores in finding food and hence would have lower net secondary production.

Energy Transformations: Food Chains and Webs

Primary and secondary production describe the major pathways of energy flow in the biosphere. A second look at these pathways, however, would indicate that the flow of energy basically depends upon the very transfer of energy from organism or trophic level to another organism or trophic level. These energy transfers constitute the so-called food chains and food webs in the biosphere.

The transfer of food energy from plant sources through a series of eating-and-being-eaten stages is known as a food chain. It is a definite arrangement of biotic components forming a sequence of levels of eating. Food chains basically assume a simple linear form as:

L- plants ] - Fj - pvores J-

~_--._- --


In a grassland, a food chain could be as short as:

In the open seas, a food chain could be:

In natural habitats, the food chain can be extended to more than four stages such as when there is more than one carnivore in the chain:

It is, however, quite uncommon to observe more than six stages in a food chain in the biosphere.

Food chains are classified into two basic types: grazing and detrital food chains (Fig. 4.3). In the grazing food chain, live plants are eaten by herbivores and the transfer of food from living plants to grazing animals and then to carnivores is quite direct and rapid. In the detrital food chain, detritus or dead plant material like dead leaves or branches is eaten by detritivores which, in terrestrial ecosystems, include animals like mites, millipedes and different earthworms and, in aquatic habitats, worms and a number of molluscs. The grazing food chain basically consists of herbivores which feed on living plants together with their predators while the detritus food chain primarily consists of detritivores which eat dead plant material together with their predators.

Wastes arid dead mgerials - - - - - - - - - - - -1

I I I 1

,---------,DETR,T”S--------- DFTRITIVORES I

+j*]

I L-----

3 MICROBIAL PREDATORS

Figure 4.3. Schematic models of the grazing food chain and the de&al food chain

f nergy Flow and Nutrient Cycles 51

The detrital food chain transfers energy to other biotic members of the ecosystem more slowly than the grazing food chain does. In spite of the cooperative eating efforts of detritivores and decomposers, it takes a much longer time for dead plant materials to be consumed. The detrital food chain is called decomposer food chain to emphasize the critical role of bacteria and fungi in the ultimate decomposition of dead plant materials in the ecosystem. Although both types of food chain may operate separately, they are not completely separated from or independent of one another as shown in Fig. 4.3. For example, the dead tissues of animals that were once a component of the grazing food chain can enter the decomposer food chain. The same is true for the faecal wastes of grazing animals.

Detrital food chains are not only more complicated and elaborate than grazing food chains but they also play a greater or more important role in terms of energy flow in the biosphere. It has been estimated that microorganisms in the decomposer food chain are responsible for as much as 90 per cent of the energy flow through the ecosystem (Edwards and Heath, 1963). It has also been noted that the grazing food chain is the dominant pathway of energy flow in the marine ecosystem while the detrital food chain is more important in forest or grassland habitats. This observation can be readily explained in terms of the degree or extent of utilization of net primary production: grazing herbivores in the forest or grasslands consume only a small proportion of the net production of the vegetation while those in the marine habitat practically eat all of the net production by the microscopic phytoplankton, leaving very little, if any at all, for the decomposers!

Although food chains operate in most ecosystems, feeding relationships are usually more complicated than the simple linear type of food transfer since animals, as heterotrophs, consume a wide variety of food. Most herbivores eat a number of plant types and most carnivores also depend for food on different herbivores and weaker carnivores as well. When several food chains get integrated or linked with one another, they form a food web, as shown in Fig. 4.4 in an African grassland. A number of food chains are quite evident in the grassland, such as:

A food web, then, is simply a number of interconnected food chains.

As the number of food chains that form a particular food web increases, the web becomes more complex and hence it becomes more difficult to identify each link or chain. To solve this problem, three generalized representations or models of food webs have been formulated: the pyramid of numbers, the pyramid of biomass, and the pyramid of energy. These models are basically trophic pyramids wherein the biotic components of the food web are grouped according to their trophic level and the relationships between the standing biomass of each trophic level are considered.

In the pyramid of numbers, the standing biomass is expressed in terms of the number of individual organisms in each trophic level. The normal or upright pyramid, as shown in Fig. 4SA, arises when the producers are small in size but numerous. When the primary producers are large in size but few in numbers, an upright pyramid starts only from the herbivore up to the top


carnivore level (Fig. 4SB). An inverted pyramid of numbers occurs only in parasitic food webs (Fig. 4.5C). The major objection to the pyramid of numbers as a representation of a food web is the non-consideration of the size of organisms in each trophic level, especially the producers whose size may range from the microscopic phytoplankton to huge forest trees.

Carcases ~ (Dead Animals)

Vultures Jackals

Lions

f&-----TA Buffalo* Impalas*

L Gazelles* Hyenas i

I I

Large Birds (Secretary Bird)

Enakes 1 (puff adder)

Rats*

Wildcats

Low-Flying Birds

Mongoose

Frogs

Grasshoppers*

f Fox

I

Hedgehog

4

PLANTS

* denotes herbivores

Figure 4.4. Major biotic components of a food web in an East African grassland (after Emberlin, 1983)


Number of Individuals Tropic Level - Number of Individuals

5 ------- Top Carnivores - 5

50 4 Carnivores - 50

500 4 Herbivores ------+ 500

5,000 4 Producers - 2

Fig. A Fig. B

1 ,ooo,ooo *- Hyperparasites

10,000 1 Parasites

1 4 Large Tree

Fig. C

Figure 4.5. The three models of pyramid of numbers: A, when the producers are small in size but numerous; B, when the producers are large in size

but few in numbers; C, in a parasitic food web. A and B are up.plight pyramids while C is an inverted pyramid.

The pyramid of biomass or weight of organisms attempts to help solve the problem of size of organisms encountered in the use of the pyramid of numbers model. In this second model of food webs, the weight of the organisms at each trophic level, rather than their numbers, is considered. Normally, the weight of the primary producers or green plants is higher than that of the primary consumers or herbivores which in turn exceeds that of carnivores in the ecosystem. This type of biomass relationship gives rise to an upright pyramid of biomass (Fig. 4.6). This type of relationship is rather rare and may be noted only in situations when producers are microscopic in size and have very rapid growth rates while consumers are large and eat most of the producers at any given time, The model also suffers from a serious limitation: it gives no indication of the amount of biomass produced or the rate at which it is produced at each trophic level.

The third model, the pyramid of energy, overcomes the objections or limitations of the other two models. In this type of trophic pyramid, the amounts of energy used by the organisms at each trophic level are measured for a sample area over a given period of time (Fig. 4.7). This model is more accurate than the other two in the sense that it does not measure organisms in terms of numbers, sizes, or even types of organisms, as grass versus cow, but looks objectively at each trophic level in the food web in terms of energy utilization or transfers. It is, however, a difficult field exercise.


Trophic Level Biomass(Dry Weight)

grams/m2

Carnivore 0.1

Herbivore 0.6

Producer 470.0

Figure 4.6. A pyramid of biomass in an abandoned fold (after Odum, 1960)

Trophic Level

Top Carnivore

Carnivore

Herbivore

Energy Content

(kilocalories/m2/year)

K

21

393

8,428

I Producer 30,810 I

Figure 4.7. A pyramid of energy for a freshwater ecosystem (after Odum, 1957)

Typical Pattern of Energy Flow in the Biosphere

Trophic pyramids at most indicate the pattern of energy storage in the ecosystem but fail to reflect the patterns of energy transfer and energy loss across the different trophic levels. The first model on the pattern of energy flow in the ecosystem was proposed by Lindeman in 1942. Known as the trophic-dynamic model, it arranges plants and animals into different trophic levels based on feeding habits and states that the rate of change in the energy content of a trophic level is equal to the rate at which energy is lost from it. At any trophic level, energy is always entering and leaving, hence there is a functional, or trophic-dynamic aspect, as well as a structural aspect in terms of trophic levels. Lindeman’s model, however, failed to include assimilation by decomposers at each trophic level.

The trophic-dynamic model has been modified and revised by later workers. A popular version of the trophic-dynamic model was proposed by Howard Odum in 1956 and is known as the hydraulic analogy of the pattern of energy flow in the biosphere. The flow of energy across the ecosystem simulates the flow of water through pipes connecting the different components of a hydraulic or water system, as shown in Fig. 4.8 and as simplified in Fig. 4.9. The basic patterns or pathways of energy flow in the hydraulic analogy model and in other trophic-dynamic models are:


1. Not all of the energy entering the biosphere is trapped or used in photosynthesis. Only about half of sunlight energy striking green plants is absorbed, of which only a fraction, about 1 to 5 per cent, is converted into the chemical energy of carbohydrates formed during photosynthesis. The rest is lost as heat, just like excess water being drained away from a hydraulic system. Green plants utilize part of the food formed during photosynthesis in respiration which also releases heat into the surroundings.

2. The energy stored after plant respiration, which is actually net primary production, flows through the food chains and webs by way of the herbivores and detritivores. Since all the biotic components of the food chains and webs also undergo respiration, large amounts of heat energy are lost in accordance with the laws of thermodynamics. Hence, the amount of energy flows through the biosphere decreases at the later stages of the food chains. In general, herbivores store only about 10 per cent of the energy they acquire from green plants. The energy storage efficiency of carnivores is of the same level; only 10 per cent of the food energy of their prey is stored.

3. Plant materials which are not eaten may remain as stored energy but eventually will reach the decomposers upon death; otherwise, they may be exported or carried away from the ecosystem, as by wind or water currents, together with the organic debris of herbivores and carnivores.

SUNLIGHT

, LIGHT

t ENERGY NOT

t ---w--d

- DETRITIVORES DECOMPOSERS

b EXPORT

ABSORBED

ui HEAT LOSS

Figure 4.8. A hydraulic analogy of thepattem of ener-gyflow (as indicated by an-ows) in the biosphere (after Odum, 1956)

Par-t I - The Knowledge Base 56

Harvested

during

PHOTOSYNTHESIS I RESPIRATION

f PRIMARY

PRODUCERS

SECONDARY TERTIARY

CONSUMERS CONSUMERS

DECOMPOSERS

J Figure 4.9. Schemtltic jlow of energy in the biosphere.

The flow of energy across the different trophic levels may also be characterized in terms of the efficiency of energy transfer and transformation. The more important energetic efficien- cies associated with patterns of energy flow in the biosphere are the assimilation efficiency of producers and consumers and ecological efficiency. In equation form, the assimilation efficiency of plants or producers, which is basically photosynthetic efficiency, is:

Assimilation Efficiency = Sunlight Energy Fixed by Plants

Sunlight Energy Absorbed by Plants x 100

Similarly, the assimilation efficiency of consumers can be expressed as:

Assimilation Efficiency = Food Absorbed or Assimilated

Food Ingested x 1oo

The ecological efficiency of the biosphere describes the efficiency of energy transfer from one trophic level to the next and is usually expressed in two ways: gross ecological efficiency and food chain efficiency. Gross ecological efficiency is simply the ratio of the gross production of a given trophic level to that of the gross production of the trophic level preceding it, and may be expressed as:


Gross Ecological Efficiency = Food Energy Eaten by Predator Food Energy Eaten by Prey

x 1OO

Here, the predator may belong to the carnivore trophic level and the prey to the herbivore trophic level which precedes the carnivore level; or the predator may belong to the herbivore level and the prey to the producer level.

Food chain efficiency is the ratio of the gross production of a given trophic level to that of the energy supplied to the preceding trophic level, and may thus be expressed as:

Food Chain Efficiency = Energy of Prey Eaten by Predatorx 1OO Energy of Food Supplied for Prey

The expression is simply an elaboration of the gross ecological efficiency equation in that it takes into account the fact that at each trophic level in the food chain a lot of food passes directly to the decomposers.

Nutrient Cycles

The biosphere is maintained by the flow of energy and the circulation of nutrients essential to life. Both processes greatly intluence the distribution and abundance of living forms. Energy and nutrients flow through the biosphere as organic matter. As such, energy flow cannot be separated from cycling of nutrients, but the efficiency and magnitude of one process depends

. on the other. The availability of essential nutrients limits primary productivity: the more nutrients are supplied to green plants, the more efficient is photosynthesis and the greater the amount of energy will tlow through the ecosystem. As energy flow increases, the circulation rates of essential nutrients are likewise enhanced.

Energy, however, flows only one way: the sunlight energy fixed as food by green plants is eventually transferred and dissipated through the food chains and webs before it finally leaves the system as heat. In contrast, the Bow of essential nutrients is cyclic so that they can be used again and again. Through the action of decomposers, the nutrients in the wastes and remains of organisms are liberated and eventually return to the nutrient pool or sink from which they originated. Hence, the flow is described as cyclic. The non-cyclic flow of energy and the cyclic flow of nutrients through the different biotic components and trophic levels in the biosphere are illustrated in Fig. 4.10. Actually, the flow of energy drives the circulation of nutrients in the environment.


Heat loss

I Sun Light

Energy

I I I AUTOTROPHS I--’ HETEROTROPHS

Heat loss

Heat Loss Heat loss

Figure 4.10. A schematic model to show how the one-way flow of ehergy drives the cyclic flow of nutrients in the biosphere. The an-ows indicate the direction of jlow. The pipes with broken

lines constitute the nutrient flow and those with complete lines the ener-gy flow.

Biogeochemical Cycles.

On a global scale, nutrient cycles are termed biogeochemical cycles: “bio” implies the participation of living organisms; “gee” refers to earth or the abiotic environment from which nutrients are obtained; and “chemical” denotes the nature of the substances being cycled or simply the nutrients themselves. Hence, biogeochemical cycles simply refer to the processes in the biosphere whereby chemical substances, especially the essential nutrients, are removed from and later returned to the abiotic environment by living organisms through energy flows and the action of decomposers.

Biogeochemical cycles are essentially nutrient exchanges between the biotic and abiotic components of the biosphere in a cyclic manner: at one time an essential element is part of an organism’s body but at some other time the same element may be a part of the abiotic environment. Furthermore, as a biotic component, a nutrient may be found or reside in a certain plant or animal or decomposer. Similarly, as an abiotic material, a nutrient may reside in the soil, in the atmosphere, or in water substrates. Where the nutrient resides at a given point of time it is referred to as a nutrient compartment. Hence, a certain compartment contains a certain amount, or pool, of nutrients.


Each biogeochemical cycle consists of two major compartments or pools: a large but relatively non-dynamic reservoir pool in the abiotic environment which is inaccessible to living organisms; and a smaller but more dynamic exchange or nutrient pool from where the nutrient is moved back and forth between the biotic and abiotic compartments. A general model of the relationships between the reservoir and exchange pools is shown in Fig. 4.11. This compartmen- talized model of a biogeochemical cycle illustrates some distinct features of nutrient flow in the biosphere: only autotrophs can extract nutrients from the exchange pool which contains available or absorbable forms of the nutrient; autotrophs incorporate the absorbed nutrients into the organic food which then passes through the different trophic levels; the decomposers are mainly responsible for the return of nutrients to the exchange pool. It is also evident that nutrients may also be lost from the cycle through outflows from some compartments, as when some consumers leave the community, or detritus is blown away and nutrients are leached away from the exchange pool. Nutrient exchange also occurs between the inaccessible reservoir pool and the nutrient pool. The reservoir pool consists basically of the fixed or precipitated and, hence, unavailable forms of a nutrient in parent rock materials. Through weathering, the nutrient may be released into the exchange pool containing the available forms.

I I

A

I I

I I I I

I I

CONSUMERS * DETRITUS

/ I I J----- AUTOTROPHS

(Food Base) 4

A

EXCHANGE 1 RESERVOIR or POOL

NUTRIENT POOL --

I A I

Figure 4.11. A schematic model of nutrient flow showing the individual comparlments and the direction of flow. Broken lines indicate outflow or loss of nutbents from the ecosystem. The

autotrophs and the exchange pool may receive inputs from outside the system.

Pat? I - The Knowledge Base 60

Based on where the reservoir pools are, biogeochemical cycles may be classified into two major types: the gaseous cycles whose reservoir pool is the atmosphere; and the sedimentary cycles with the earth’s crust as their reservoir pool. The gaseous cycles have also been termed global cycles where carbon, nitrogen, oxygen and water are involved (Etherington, 1978). The gases in the atmosphere are globally circulated so that global nutrient cycles in effect link together all of the world’s living organisms in one immense ecosystem, the biosphere or the whole earth ecosystem. A generalized diagram of the global cycles of carbon, nitrogen and oxygen is depicted in Fig. 4.12.

The sedimentary cycles have the soil as the exchange pool of essential inorganic nutrients that include phosphorus, potassium, calcium, magnesium, iron, zinc, boron, manganese, chloride, copper and molybdenum. These nutrients are usually in solution and, unlike the atmospheric gases, cannot circulate on a global scale, hence the term local cycle which is limited within a specific ecosystem. The essential nutrient sulphur is quite unique because its circulation involves both an atmospheric and a sedimentary nutrient pool. A generalized scheme of a local cycle is shown in Fig. 4.13. In spite of their differences, both types of nutrient cycles nevertheless share two common features: first, plants extract essential nutrients from the exchange pool and convert these into organic food, and second, decomposers are the vital link in the release of nutrients back to where they came from, the exchange pool, so that these can be used again by plants and the cycle can once again turn.

1

ATMOSPHERE I

CONSUMERS

%I- PLANTS

I ZC- -’ / j SOIL SOLUTION / j

(NUTRIENT POOL)

+

I . A

I I I

DECOMPOSERS t-- - - - - - - ---

Figure 4.12. A generalized schematic diagram of the different compart,nents (as indicated by boxes) and the flow of nutrients (as indicated by arrows) in the global nutrient

cycles. The dashed lines are the majorpathways of the nitrogen cycle.


The Stability and Rates of Biogeochemical Cycles

In nature, both local and global nutrient cycles do reach a steady state and are assumed to be stable. Their susceptibility to disruption by human activities and physical changes in the environment, however, varies. The gaseous cycles for carbon and oxygen, for instance, can self-adjust easily to local changes in the exchange pools because of the large reservoir pool, the atmosphere itself. The increase in carbon dioxide levels in urban air due to fossil fuel combination can readily be dissipated by wind currents or reduced by plant absorption during photosynthesis. The sedimentary cycles are more easily disrupted or disturbed by local events because of the limited size and mobility of the exchange pool and the inactivity of the reservoir pool. Local droughts render sedimentary nutrients less available and excessive leaching decreases nutrient levels in the exchange pool. Both processes can seriously disrupt local nutrient cycles and it will take some time for the cycles to again attain stability.

ti

SOIL SOLUTION

(EXCHANGE POOL)

Figure 4.13. A generaked schematic diagram of a sedimentary or local cycle.


The compartments of biogeochemical cycles exchange nutrients. Measurements of the entry and outflow of nutrients for each compartment in a cycle have shown great variations in the rates of transfer of nutrients between two compartments, termed the flux rate which is a measure of the amount of a nutrient passing from one compartment to another per unit time. Flux rates are influenced by the chemical nature of the nutrient involved, growth rates of plants and animals, rate of decay of organic matter and human activities.

Some nutrients are cycled at faster rates than others because of their chemical properties and the manner in which they are utilized by living organisms. Gaseous nutrients are usually cycled faster than sedimentary substances. The growth of the bigger living organisms in the community will affect the absorption rate of the nutrient and its flow through food chains. Faster growth rates require more nutrient uptake for the synthesis of more protoplasm. The rate of decay of organic matter depends primarily on the abundance of decomposers which is determined by climate and soil type. The productive soils of warm humid environments favour the growth of decomposers that would hasten the breakdown of organic litter in contrast to the very slow decomposition rates in the soils of cold humid habitats. The rate of organic decay in acidic soils is much slower than that in alkaline soils since an acidic medium is unfavourable for the growth of major decomposers. Faster rates of organic decay speed up the return of nutrients to the exchange pool and, hence, the.completion of the cycle is also faster.

Two major human activities of late have significantly and sometimes disastrously influenced nutrient cycles in the biosphere. The ever-increasing rates of combustion of fossil fuels have released great quantities of carbon and sulphur into the atmospheric pool and created air pollution problems. Extensive deforestation, especially in the tropics, has depleted the nutrient pools and impoverished sedimentary cycles of once productive environments.

A brief consideration of specific global and local nutrient cycles will be most helpful in understanding better the fragile nature of biogeochemical cycles in the biosphere. Two global cycles, carbon and nitrogen, as well as two local cycles, phosphorus and sulphur, will be discussed to illustrate the physical and biological processes involved in each cycle. Disruptions of these cycles has created problems of environmental degradation.

The Carbon Cycle

The major pathways and compartments of the carbon cycle are summarized in Fig.4.14. The reservoir of this nutrient is the vast atmosphere. Practically all the carbon in the biotic compartments originate from photosynthesis. The total amount of carbon assimilated annually by green plants in the biosphere is quite significant: around 3 per cent of the total carbon dioxide content of the atmosphere (Hall and Rao, 1977). Some of the carbohydrates produced in photosynthesis are incorporated into plant tissues and used in respiration, which releases carbon dioxide in the atmosphere. Around half of the carbon assimilated by plants, however, will eventually end up as plant litter in the dead organic matter pool.

Some of the carbon in the plant body enters the bodies of consumers through the food chains but part of this will be released also as carbon dioxide during respiration. Consumers excrete organic wastes and eventually die; both processes contribute to the dead organic matter pool. Long food chains and complicated food webs can expand the carbon cycle considerably. The dead organic matter compartment is actually a subsidiary or secondary carbon pool which may move on to the decomposers or be stored in the ecosystem and converted to fossil fuels through geological time. The combustion of fossil fuels releases the stored carbon back to the atmosphere. Another process that leads to the storage of carbon in the marine environment for


very long periods ol’ time is the formation of carbonate rocks. Carbon dioxide t’rom the atmosphere reacts with sea water to form calcium carbonates which are used for shell formation in a variety of marine organisms. When such organisms die, their shells eventually will form carbonate rocks which again through geological time may be weathered away to return carbon into the atmospheric reservoir. Volcanic vents continuously emit carbon dioxide from the deep interior of the earth into the atmosphere.

- ATMOSPHERIC RESERVOIR * c OF CARBON DIOXIDE

Photosynthesis Respiration

FOSSIL FUELS 4

I I MARINE I >”

.u CARBONATE ROCKS 1 ORGANISMS

f3 WITH SHEELS

z

Figure 4.14. The major cotnpnrtments nnd processes in the globnl crrrbon cycle.


The Nitrogen Cycle

Nitrogen is a major component of living matter and of the atmosphere which contains around 80 per cent by volume of this gaseous nutrient. As in the carbon cycle, the atmosphere is the reservoir pool of nitrogen but unlike carbon, nitrogen cannot be utilized directly by plants but must first be converted into chemical compounds, which can be absorbed by plants, in the soil or exchange pool. The global nitrogen cycle is illustrated in Fig. 4.15.

Atmospheric nitrogen is converted into nitrates, an oxidized form of the nutrient which is most readily absorbed by plants, by two major processes: biological fixation and lightning. Biological fixation is performed by soil microorganisms, notably bacteria and some blue-green algae. Some of the bacteria which fii atmospheric nitrogen through a complex and enzyme- mediated series of reactions are free-living, or autotrophs, such as Acetobacter and Clostridium while others reside in the roots of legumes in a symbiotic fashion, such as Rhizobium. The major free-living nitrogen fixing blue-green algae are Nostoc and Anabaena. The nitrates formed are either used by the microbes themselves or excreted into the soil solution. The other pathway of atmospheric nitrogen conversion to nitrate involves thunderstorms and lightningwhich produce

ATMOSPHERIC 4

NITROGEN

RESERVOIR

ANIMAL 4

PROTOPLASM

Lightning 1

Biological

Nitrogen

Fixation by Denitrifying

Bacteria PLANT

PROTOPLASM - and A’gae

‘I DEAD ORGANIC NITRATES -

MATTER NOa I

Deco&osers Nitiate

+ _ Bacteria

I .

AMMONIA Nitrite NITRATES

NITROGEN w

Bacteria NO2

Leaching

GUANO MARINE Food SHALLOW w MARINE

FERTILIZERS BIRDS - -a

Chains SEDIMENTS

Figure 4.15. The compal?ments and processes involved in the global nitrogen cycle.


electrical energy that will combine nitrogen and oxygen. The nitrates thus formed will eventually be brought down to the soil through rainfall.

Nitrates absorbed by plants are used for the synthesis of amino acids and proteins which are essential for the formation of new protoplasm. Nitrogen in the form of plant protoplasm may pass through the grazing food chain via herbivores and carnivores or the detritus chain after death of plant parts or the plant itself via decomposers. Heterotrophs excrete wastes or may also die to form dead organic matter which also are acted upon by decomposers. Proteins released from the dead organic matter by decomposition serve as food for a number of bacteria. The utilization of the proteins as food by a host of soil microbes releases ammonia and mineral elements through a process known as mineralization. The released ammonia is utilized as an energy source by nitrite bacteria such as Nitrosomonas to form nitrite which is likewise readily converted to nitrate bacteria such as Nitrobacter. The released nitrate again enters the exchange pool.

Nitrates not absorbed by plants may get lost from the exchange pool through the action of a number of microbes in a process known as denitrification. Denitrifying bacteria such as Pseudomonas, Thiobacillus and Micrococcus transform nitrates to nitrite and then to ammonia to eventually release molecular nitrogen back into the atmospheric reservoir. These microorganisms thrive in oxygen-deficient habitats such as lake bottoms and water-logged soils. The exchange pool may also lose nitrates through heavy rains that bring materials deep into the soil in a process known as leaching. The leached nitrates eventually are lost to shallow marine sediments where they may be passed through the marine food webs, ending up in the protoplasm of marine birds and fishes. Through the droppings or excreta of marine birds, known as guano fertilizers, the nitrates may ultimately reenter the exchange pool. If unutilized, the nitrates in the shallow sediments may be lost for millions of years into the deep marine substrates.

The Phosphorus Cycle

Phosphorus, a key element in metabolic processes in all living organisms, is much less abundant than either nitrogen or carbon, existing at a ratio of about 1 to 23 in relation to nitrogen in natural environments (Hutchinson, 1970). As such, phosphorus is usually a limiting nutrient in the biosphere. Unlike nitrogen and carbon, this nutrient has no atmospheric pool and hence is not globally circulated. The reservoir of phosphorus in nature lies in the relatively insoluble ferric and calcium phosphates of crystalline phosphate rocks. Through weathering, the locked phosphates may be released to the exchange pool in the soil and sediments. A typical phosphorus cycle in the biosphere is shown in Fig. 4.16.

The exchange pool simply involves the circulation of phosphates between living protoplasm and the soil or shallow sediments of aquatic environments. Plants absorb phosphates from the nutrient pool and assimilate these into living matter which then moves through the food chains and webs. Metabolic wastes and death in the different trophic levels create a pool of dead organic matter containing phosphorus. Decomposers break these down and phosphates are released to the exchange pool, especially through the action of phosphatizing bacteria.

Some of the phosphates in the exchange pool may be leached through rainfall and carried to the shallow marine sediments. As in the nitrogen cycle, the phosphates in the sediment pool may be assimilated into the bodies of marine fishes and birds through the food webs. The droppings of birds on land may create guano deposits containing phosphorus and if these are used as fertilizers the nutrient may find its way back to the exchange pool. If the phosphates in


c--c PLANTS * ANIMALS

DEAD c

ORGANIC

) MAlTER

DECOMPOSERS

I Fettilizer Use

GUANO

DEPOSITS

MARINE

SOLUBLE

c PHOSPHATES 4

IN SOILS

AND SEDIMENTS

Leaching -~- Weathering

ROCKS WITH

PHOSPHATE

FISHES

Figure 4.16. The conqwmnents and processes involved in the phosphorus cycle.

the shallow sediments are not absorbed into the food chain, the nutrient may be lost to the deep marine deposits, making it inaccessible to the cycle perhaps for millions of years.

The Sulphur Cycle

Sulphur, also a key element of protoplasm, has a unique sedimentary cycle in that it has an atmospheric compartment. In nature, sulphur occurs in three oxidation states: hydrogen sulphide (H2S), sulphites (SO2) and sulphates (SO4). The reservoir pool of the nutrient is the inorganic sulphur in rocks and fossil fuels which may release sulphates into the exchange pools in the soil or marine sediments through reduction-oxidation reactions. Through combustion of fossil fuels or volcanic action, the reservoir may also release SO2 and H2S, respectively, into the atmospheric pool. The unique features of the sulphur cycle are reflected in Fig. 4.17.

Sulphates absorbed by plants from the nutrient pool are used in protein synthesis and assimilated into living matter which will pass through the different trophic levels via food chains.


Death and metabolic processes yield dead sulphur-containing organic matter for the decomposers. Mineralization eventually releases the sulphur into the exchange pool.

Leaching may remove the unabsorbed sulphates from the exchange pool. The leached sulphates may be reduced to sulphides by reducing bacteria such as Desulfovibti desulftians under anaerobic conditions as in water-logged soils. The sulphides may either escape into the atmospheric pool or be oxidized by chemosynthetic bacteria to release inorganic sulphur which may eventually reach the reservoir. The major pathway for the return of sulphur from the reservoir pool to the exchange pool is by erosion and weathering. Atmospheric sulphur returns to the exchange pool mainly through precipitation.

The four nutrient cycles clearly illustrate the circular pathway of nutrient flows between the biotic and abiotic components of the biosphere. Similar sedimentary cycles could be constructed for other essential nutrients. The hydrological cycle was not discussed, not because it is considered unimportant but rather because it is more than a mere nutrient; providing the very milieu or medium of life. But as a cycle, just like that of carbon or the rest, water also circulates in the biosphere through biotic and abiotic compartments with the aid of energy flows.

1 PLANTS ANIMALS I

Sulphur Oxides

____) ATMOSPHERIC Hydrogen SULPHUR

Sulphide RESERVOIR

DECOMPOSERS

Mineralization

SOLUBLE SULPHATES - IN SOILS AND 4

SEDIMENTS A I

Oxidation Red&on t

1 SOLUBLE SULPHIDES IN SOILS AND Leaching SEDIMENT

A I Reduction Oxidation

I I v 1

Figure 4.17. The compartments and processes involved in the sulphur cycle.


In Summary . The biosphere is basically maintained by energy flows and nutrient cycles. Both processes

operate together as a unit, transforming materials and energy into living matter. One regulates the rate of the other, both positively and negatively, to attain relative stability. Efficient energy llowsenhance the circulation of nutrients up to a certain level, beyond whichefficiencyofenergy 110~s is limited by the rates of nutrient cycles. Green plants initiate bothenergy flow and nutrient cycles in the biosphere.

The flow of energy in the biosphere is governed by the first two laws of Thermodynamics: energy can only be transformed; and the transformation is not 100 per cent efficient. The ultimate source of energy is sunlight which is transformed by autotrophs, the green plants, into the chemical energy of food through photosynthesis. The food, through webs and chains, may enter either the grazing or the detritus routes with substantial losses in energy released as heat given off through respiration. The ratio of energy flow between trophic levels represents ecological efficiency which decreases as the food chain or web lengthens. Pyramids of numbers, biomass and energy across trophic levels are also illustrative of energy flow. It is always the case, however, that the amount of solar energy entering the biosphere is equal to that of the heat energy leaving the system.

While energy in the biosphere tlows in a one-way direction, essential nutrients are exchanged between abiotic and biotic compartments perpetually in a cyclic or circulatory manner. Green plants extract nutrients from exchange pools and incorporate these into living matter which then moves through the food chains via biotic compartments. Decomposers are always primarily responsible for returning the nutrients back to the exchange pool by acting on metabolic wastes and dead organic matter. A larger reservoir pool supplies the nutrients in the smaller exchange pool.

Based upon the type of reservoir pool, nutrient cycles arc of two major types: atmospheric and sedimentary. Since gaseous nutrients such as carbon and nitrogen are constantly being circulated in the atmosphere, their cycles are also termed global cycles. Essential elements in the sedimentary pool such as phosphorus and sulphur are not mobile or widely circulated, hence their movements are termed local cycles. Except for nitrogen, the essential nutrients are directly absorbed from the exchange pools by green plants. Atmospheric nitrogen must first be converted into absorbable forms by soil microbes or by lightning before it enters the exchange pool. In all cycles, uncirculated nutrients are constantly being lost to the reservoir pool or to the deep sediments of the oceans. Those lost to the reservoir pool may be returned to the exchange pool through weathering but nutrients lost to the deep marine sediments will be inaccessible to the biosphere for millions of years.

Although global cycles are more resistant to disruption than local cycles, both are fragile. Atmospheric, water and land pollution arise mainly from the introduction of excess nutrients or foreign materials which not only disrupt natural nutrient cycles but may also, in the long term, affect energy flows since both operate together in the biosphere as a unit.


References

Andrewartha, H.G. 1961. Introduction to the Study ofAnimal Populations. University of Chicago Press, Chicago.

Beard, J.S. 1973. Thephysiognomic approach. In: R.H. Wbittaker (ed). Ordination and Clas- sifiation of Communities. Dr. W. Junk Publishers, The Hague. pp. 355-386.

Billings, W.D. 1964. Plants and theEcosystem. Wadsworth Publishing Company, Inc., California.

Connell, J.H. and R.O. Slatyer. 1977. Mechanisms of succession in natural communities and their role in community stability and organization. American Naturalist 11 l-l 119-l 144.

Clements, F.E. 1916. Plant Succession: An Analysis of the Development of the Vegetation.’ Carnegie Institute Publication No. 242. Washington, D.C.

Clements, F.E. 1936. Nature and structure of climax. Journal of Ecologhy 24:252-284.

Cowles, H.C. 1901. The physiographic ecology of Chicago and vicinity. Botanical Gazette 31:73-108, 145-181.

Elton, C. 1927. Animal Ecology. Sidgwick and Jackson, London.

Evans, F.C. 1956. Ecosystem as the basic unit in ecology. Science 123:1172-l 128.

Horn, H.S. 1981. Succession. In: R.M. Maty (ed). Theoretical Ecology. Blackwell, Oxford, England. pp. 253-271.

Hutchinson, G.E. 1959. Homage to Santa Rosaha, or why are there so many kinds of animals? American Naturalist 93:145-159.

Krebs, C. 1985. Ecology: The Experimental Analysis of Distribution and Abundance, Third Edition. Harper and Row, Publishers, Inc., New York.

Odum, E.P. 1963. Ecology. Holt, Rinehart and Winston, New York.

Peet, R.K. 1974. The measurement of species diversity. Annual Review of Ecology and Sys- tematics 5285-307.

Chapter 5

Population Dynamics in an Ecosystem*

An ecosystem consists of living (organic) and non-living (inorganic) components which keep in balance with each other through a cyclic phenomenon. The inorganic matter is replenished by the organic matter through death of the living things which in turn support the life activity in an ecosystem. Any drastic change in either of the components can break the cycle and thereby destroy the balance in the ecosystem. For example, in an aquatic ecosystem, the increase in nutrient level in water by intensive use of fertilizers can lead to ecological problems such as eutrophication. The excess nutrients stimulate the growth of algae and other water plants. When these plants die they use most of the oxygen present in water for decay and release huge amounts of carbon dioxide during the process of decay. If the load of organic waste imposed on the system becomes too great, lhe demand of the bacteria of decay for oxygen may exceed the limited oxygen content of water. When the oxygen falls to zero, the bacteria die, the biological cycle breaks down, and the organic debris accumulates, leading to pollution. The limited supply of oxygen in the water and higher concentration of carbon dioxide released during decay of plants lead to death of other animal life in water thus making the whole ecosystem biologically dead. This is a simple example of the general tendency of an ecosystem for cyclic responses, for dramatic overgrowths and equally dramatic collapse.

Conditions for Growth of Populations in an Undisturbed Ecosystem

All living things need food, water, space, and energy for their survival and growth. The growth of population of individuals is also dependent on these physical factors. Any significant change in any of these factors can become a limiting factor for the further growth of a population. Most animal populations live in balance with the natural system and under normal conditions their population size remains almost constant over a period of time.

Under theoretically ideal conditions, when there are no restricting factors imposed by the physical or biotic environment, a population could be considered capable of exhibiting a maximum intrinsic rate of increase. This ability of a population to grow maximally and exponentially is known classically as the biotic potential.

Small organisms such as bacteria, amoeba or yeast possess a fantastic capacity for population growth. A bacterium dividing every twenty minutes would produce a colony one foot deep over the entire earth in a day and a half. One hour later, the layer of bacterium would be over

* Prepared by Dr. Il. C:. Shama, Regional Adviser for In-School Population Education, Unesco Bangkok.


our heads. In the same way, if man continues to grow at the present rate of exponential growth for 900 years, there would be some sixty million billion people. This is about 100 persons for each square yard of the earth’s surface; land and sea.

The biotic potential is, however, almost always an indication of a theoretical rate of growth, not an actual one. This is expressed by the realized intrinsic rate of increase. For example, man may have lower biotic potential than an amoeba species population and higher biotic potential than the tiger or the elephant. But under natural conditions the natality rate equals the mortality rate and the population size remains constant on the average. Thus the biotic potential is checked by natural circumstances as well as by cultural conditions. This check is imposed by environmental resistance, which exists when some factor (or factors) of the environment becomes limiting and decreases the natality rate, increases the mortality rate, or does both. This limit to the biotic potential of a population imposed at a particular population size by environmental resistance under a given set of conditions is most generally known as the carrying capacity of that environment.

The relationship between the biotic potential, population growth and environmental resistance in the case of animals and plants forms acharacteristicsigmoid or”S”shaped or logistic curve.

Density (N) Environmental

A Resistance Carring Capacity (K)

Stabilized Population

Time (T)

Figure 5.1. Theoretical relationship between biotic potential, environmenc~~l resistance md logistic curve. (Source:: R.C. Sharma, 1988, p. 278)

Most animal and plant populations in an undisturbed ecosystem are generally controlled by feed-back mechanism. It is rare that animal and plant populations will grow beyond the limits of available food supply or the carrying capacity of the environment. A variety of self-regulatory mechanisms, physiological and behavioural, start functioning and regulating the populations before the food supply or resources are exhausted. By one means or another such as infanticide and cannibalism, spontaneous abortion, parental neglect, genetic deterioration, death by stress and reduced fertility rate. the population of animals is kept within the limits of the carrying capacity of the environment.

Population Dynamics in an Ecosystem 73

There are at least three models which can be constructed on the basis of the relationship between the biotic potential and the capacity of the environment (Fig. 5.2). In the first model the rate of population growth decreases before the environment limits are reached. In this case the population growth curve is S-shaped i.e. logistic.

The second model represents the case where the population overshoots the limits of the carrying capacity of the environment and then dies back in either a smooth or an oscillatory way. This results in a J-shaped curve.

The third model depicts the population overshooting the carrying capacity of the environment, thereby decreasing the nonrenewable resources and then falling sharply. This causes what is called the crash curve.

r --- ------ ----- ZJ b 6 ti 2

d a0

Time Time

Model I S or Logistic Curve Model III Crash Curve

Time Time

Model II J-Shaped curve

Figure 5.2. The relationship between the biotic potential and the capacity of the environment. (Source: R.C. Sharma, Ibid. p. 279)


Nobody can predict with certainty which of these models will apply in the case of human. There are many variables which can affect the growth of human population. These include: cultural and technological, available industrial and agricultural capital, cultivable land, pollution, consumption patterns and natural resources. Different models have been constructed on the basis of different assumptions of change in one or more of these variables. Some of these models are discussed in this chapter.

Interdependence among Populations

Plants receive energy from the sun and convert it into chemical energy. Similarly, plants get food from the soil. In both cases of energy transfer from the sun and the soil to the plant, some energy is lost as heat and cannot be’used to make the living matter of the plant. Similarly, when plants are eaten by animals some energy is lost in the transfer of energy from the plants to the animals. This condition leads to a kind of relationship between the biotic mass, plants and animals, which is represented by what is called Food-Pyramid. There is a loss of energy to the extent of 85 per cent to 90 per cent at each level of transfer. For example, if the total energy available in plants is 10 000 calories, only about 1 000 calories will be available to the first level of consumer, i.e. herbivores. The second level will have about 100 calories, third level about 10 and fourth level only about one calorie. If a carnivore is at the fourth level it should have a base of plant food equivalent to 10 000 calories or simply we can say that one kilogram of the fourth level consumer will need about 10 000 kilograms of plant food. It is for this reason that an ecological chain rarely has more than five links or chains from producer to the top predator. This is one reason why you do not find big fish in a small pond or a lion in a small jungle.

There is interdependence among different living things in the natural ecosystem. The behaviour of any given living member of the system is dependent on the behaviour of many others. The specific relationships are varied: one organism may provide food for the other; one organism may parasitize and kill another; or two organisms may be mutually dependent on each other. Sometimes one animal may be dependent on another which in turn may be dependent on the third and so on forming what is called the food chain. Generally, in an ecosystem there are many different kinds of food chains which support each other thus forming a food web. See Fig. 5.3. The degree of stability of an ecosystem depends closely on the degree of complexity of the ecological web. In such a system any change in the population of any one organism is likely to have effects on other organisms in the same or other food chains. Because of these numerous interconnections an intrusion in an ecosystem is likely to have effects which spread out in the system and may affect organisms and parts of the environment often very remote from the initial point of intrusion.

Human fits at different trophic levels - as a primary consumer as well as secondary or even 4th or 5th level consumer. All vegetarians are the primary consumers. We have seen that there is a considerable loss df energy during its transfer from one level to another. People who are vegetarians, i.e., the primary consumers, make the most efficient use of energy. It is, therefore, possible to support a larger population ofvegetarians than non-vegetarians. Vegetarianism may be one of the alternatives for human to feed the growing population all over the world.


,

Zebra A@-

Figure 5.3. The food web

Human Population as a Part of the Natural Ecosystem

Human beings are biologically similar to animals and they are part of the natural system. The population of primitive human was maintained at an optimum level by a number of factors. There were traditions which helped to keep the population down. Some of these traditions were similar to animal practices. Some of the traditions practiced by the primitive human were infanticide or compulsory abortion, cannibalism, head-hunting, human sacrifice, ritual murder, territorial defence or home-range, etc. It was the industrial revolution during the 18th century which effectively destroyed the older traditions, especially cannibalism, headhunting and human sacrifice. The advent of modern medicine and technology also reduced the infant death rates and general mortality rates. The humanistic preoccupation with the prolonging of age, saving the handicapped, physically and mentally defective, etc., also added to the population increase.

Human beings have the capability of playing with the environment and changing it to suit their needs. Through the cumulative cultural advancement and new technological discoveries human have been changing the environment to meet their needs. In the process of changing the environment for their benefit they have already done a lot of damage to the ecological webs in the system. The effects of their intrusion in the natural system are becoming more and more evident . We have now reached the stage where humans are getting concerned about the deteriorating environment because it is affecting human. One of the major concerns now is that if the environment continues deteriorating at the present rate because of human population increase and increased human interference in the ecological processes in the name of development, human beings will face a challenge to their very existence in the near future. The laws of nature which regulate the populations of other animals will ultimately apply to human as well, which would mean starvation, disease and death on a massive scale.

What kind of controls will apply to the modern human, only time can show. But if we take nature as a model, there are two possibilities. One is the sane and human programme of population control and the second is death by stress. Since our population problem has a cultural cause, we must provide a cultural solution. If we fail to do so, there is no doubt that the law of nature which applies to other animal populations, i.e., death by stress, may bring the population


crash. It is also possible that the stress due to density may start showing its effects on the biological mechanism of human beings, causing reduced fertility as is shown in the case of some animals. Other factors which are the by-products of cultural change, such as automobiles, nuclear bombs, drugs, pollution, etc. may also bring the population down by increasing the death rates. The cause of life when taken beyond its limits becomes the cause of death. A simple example to illustrate this point is that food is needed to keep one alive but if it is eaten beyond the digestive limits of the body it can become the cause of his death. The different cultural innovations which have helped to decrease misery and death may ultimately become the cause of misery and death if taken beyond a particular limit.

Growth of Human Population

The world population was almost stationary during hundreds and thousands of years of the old stone age at an estimated total of about ten million people. Sometime between 8,000 B.C. and 6 000 B.C. people learnt to grow and so could support large populations. As a result, human population increased to half a billion by 1650 AD., i.e., about a fifty times increase in 7 000 to 9 000 years. In the next 200 years, i.e., by 1850, the population doubled and reached its first billion point. It took about 100 years to add another billion and about 45 years to double the population to 4 billion in 1975. It took only 12 years to reach the 5 billion mark on 11 July 1987. At the present rate of growth, we will add another billion in the next twelve years. The world population will be over 6 billion by the year 2000, most of the growth taking place in the developing countries. At present we are adding about 500 million people in about six years’ time, a population figure which took thousands of years to reach before 1650 A.D. About 342-000 babies are born each day in the world and about 135 000 die, leaving a net increase of 207 Ooo. By the end of the week there will be nearly 1.5 million more people.

I I I I I I I I I

OLO NEW STONE AGE NEW BRONZE STONE AGE COMMENCES STONE AGE AGE IRON AGE

A .A h A v v- Y

1

I 1 I I & ’ 0 APPROX. Boo0 7ooO f%W 50K1 4ooO 30K1 Moo loo0 B.C.A.O. loo0 2000

--c 2 MILLION B.C. B.C. B.C. B.C. B.C. B.C. B.C. B.C. A.D. A.0 YEARS

+----- Period 1 I- Period 2 p+Petiod 3

Figure 5.4. World population through history. (Source: Population Bulletin. XVUJl.)

The population is not evenly distributed around the world. More than half of the world’s population lives in Asia. The developed regions of the world, i.e., Europe, North America,


USSR and Oceania, had only about 22 per cent of the total world population in mid 1988; the remainder distributed in the developing parts of the world.

In addition to the large concentration of population in the developing countries, the percentage of population under 15 years and over 64 years, or what is called the dependency ratio, is also very high. The population under 15 years is about 45 per cent in Africa, 36 per cent in Asia and 39 per cent in Latin America whereas it is only about 23 per cent in North America, 22 per cent in Europe and 29 per cent in Oceania. However, the percentage of population over 64 years is higher in developed regions of the world. North America has about 11 per cent of its population over 64 years, Europe about 13 per cent and Oceania about 8 per cent. It is only 3 per cent in Africa, and 4 per cent in Asia and Latin America.

The high dependency ratio in the developing countries means that the working population in the age-group 15 to 64 has to support a large population with requirements for housing, clothing as well as education, health and other social services. The large young population in developing countries has demographic implications also in the near future.

Projections of Population Change

According to the Global 2000 Study, the world’s population will increase to about 6.35 billion in 2000, under the Study’s medium-growth projections.

Most of the population growth (92 per cent) will occur in the less developed countries rather than in the industrialized countries. Of the 6.35 billion people in the world in 2oo0, 5 billion will live in the developing countries. The share of the world’s population in the developing countries is expected to reach 59 per cent by 2000.

The United Nations estimates that the global population could stabilize itself at 10.5 billion in the year 2110. The United Nations projects three scenarios for stabilization - high, medium and low, based on modest and significant rates of decline in fertility. The high variant results in a projected population of 14.2 billion, medium variant 10.5 billion and the low variant 8 billion.

The following figure shows the distribution of population in different regions of the world in 1950, 1980 and 2025.

19Pl : 2.5 billion 1980 : 4’5 billioo

South Ario

2025 : 8’2 billIon

Figure 5.5. Percentage distribution ofpopulation by region in 1950, 1980 and 2025. (Source: United Nations.)

Part I- The Knowledge Base 78

Table 5.1. Poprtlotion Situation in Major Regions and Selected Countries *

Region POQU~.?tlO~ Crude Crude Natural Population Infant %Age Life Urban Or Estimates Rirth Death Increase 2000 Motality under15 mcranq Population

Country Mid-I%% Rate Rate (million) Rate &over64 at birth (1) (2) (3) (4) (5) (6) (7) (8) (9) (10)

World 5,128 28 10 1.7 6,178 77 3316 63 45

Africa 623 44 15 2.9 886 110 45l3 52 30

SOUTHEAST

LATIN 420 32 7 2.5 537 57 3815 66 68 AMERICA

Europe 497 13 10 0.3 506 13 21/13 74 75

USSR 286 20 10 1.0 311 25 25/9 69 65

Oceania 26.2 20 8 1.2 30 36 28P 72 70

* Source: Populntion Reference Burenu, Inc. World Populntion Dntrr Sheet,

P.C GNP

1988 (4

(11) 3.010

620

1,020

160

270

160

350

400

1.850

12,850

14,100

17.500

1,720

8,170

7,400

9,050

W(!shington, D. C. 19&Y.

Population ,Dynamics in an Ecosystem 79

Asia and Africa will account for about 75 per cent of the world’s total population in the next 35 years or so. These two regions contain the greatest proportion of poor people. Malnutrition, ill-health, illiteracy and the lowest life expectations accompanied by inadequate technology and economic poverty are predominant in South Asia and Africa. It is not very difficult to imagine the miserable plight of the people in these regions in the next century.

Implications of Population Increase on the Environment

There are direct as well as indirect effects of population increase on environmental pollution. Other things being equal, the greater the population, the more significant are the changes brought about in the environment. If there are more people, we need more food, energy, housing, clothing, transportation, etc., all ofwhich lead to environmental pollution. Poor quality of food, sanitation, water supply, housing, health services, employment, and other services are common problems in countries with higher rates of population increase. The problem of domestic sewage and solid waste is directly related to the number of people. As the number of people increases, the space per person for waste disposal decreases. The small mountains of dumped waste are quite common sites in many urban areas. Water pollution with sewage and industrial wastage provides one of the examples accompanying population growth. The carrying and the decomposing capacity of the rivers is overloaded by the increase in urban population and development of industrial complexes leading to the disturbances of the river ecosystems. If a few people per kilometre live along a large river their sewage may be dumped directly into the river and natural purification will occur. But if the population increases, the waste-degrading ability of the river becomes overstrained and either the sewage or the intake of water must be treated if the river is to be used for drinking or for irrigation.

Fertilizer --f Factories

More

Food Other gOOdS Automobiles Energy

PEOPLE

Figure 5.6. Relations between increasingpopulation and environrnentalpollution (Source: R. C. Sharma, op tit p. 446)

1_- II.--_.-I.___-


Fig. 5.6 illustrates the relationship between increasing population and environmental deterioration. It can be seen that more people need: more food; more clothing; housing apd other goods; more automobiles; and more energy. To meet these growing needs, fertilizers, factories, pesticides, fuel and nuclear energy are utilized. These in turn lead to water pollution, air pollution, thermal pollution and radioactive wastes which, together with the sewage and solid wastes of people, result in environmental pollution. Apparently, more people means more environmental pollution.

The Future of Human Population

The report on “Limits to Growth” suggested a number of models of human population projections on the basis of different variables such as industrialization, food production, pollution, resource depletion, etc. Each of these variables works on a feedback mechanism.

Different world models (see Fig. 5.7) were developed in a computer system for the years 1900 to 2100 maintaining the following eight alternatives:

l Population (total number of persons).

l Industrial output per capita (dollars equivalent per person per year).

l Food per capita (kilogram grain equivalent per person per year).

0 Pollution (multiple of 1970 level).

l Nonrenewable resources (fraction of 1900 reserves remaining).

l Crude birth rate (births per 1000 persons per year).

l Crude death rate (deaths per 1000 persons per year).

l Services per capita (dollars equivalent per person per year).

In the world model it is assumed that there will be no major changes in the physical, economic or social situations and that food production, industrial output and population will grow exponentially. As a result of resource depletion, industrial growth will slow down. More investment will be needed to obtain the depleting resources and finally the investment will not keep up with the depreciation, and the industrial base will collapse. As a result of the collapse of the industrial system the agricultural system will also collapse because it is dependent on industrial outputs such as fertilizers, pesticides, energy for mechanization, laboratories, com- puters, etc. The population will continue growing for some time as a result of the delays inherent in the age structure and the process of social adjustment, but finally the population will decrease sharply because of the lack of food and health services and increasing death rate. This model projects a “population crash” sometime after the middle of the 21st century. This model is based on the assumption that the population collapse will be due to the resources crisis.

The second model assumes that the resources would be doubled as a result of technological advances. This will lead to more industrial growth which will increase the pollution level, thereby causing a rise in death rate and lack of food. The population will fall sharply again causing a population crash sometime in the middle of the 21st century. At the same time the resources will be severely depleted in spite of the doubled amount initially available, simply because of the industrial consumption at an exponential rate.


----- --~----------------------. . * P . . m * *

0 - .

Figure 5.7. World model standard run (Source: Meadows et. al. , 1972).

In the third model the resources are increased as a result of the availability of unlimited nuclear energy. Even in this case the population growth will decline at about the same time as in model two as a result of pollution.

The fourth model assumes a decline in the pollution level and increase in resources and industrial production as a result of technological advances. According to this model the population growth will decline as a result of the limit imposed by arable land and decline in the availability of food per capita.

The fifth model assumes ‘unlimited’ resources, pollution control and increased agricultural productivity. The combination of these three will encourage higher rates of population and industrial growth which ultimately will create a pollution crisis resulting in the decline of population size.

The sixth model assumes ‘unlimited’ ,resources, pollution control and ‘perfect’ birth control. In this case the crisis is only shifted to a slightly later date. In spite of perfect birth control measures the pollution will continue to grow, though at a slower rate, thereby creating a food crisis. In this case the population will decline much before the year 2100.

The seventh model assumes ‘unlimited’ resources, pollution controls, increased agricultural productivity and ‘perfect’ birth control. According to ihis model the population will reach a constant role of growth with a world average income per capita equal to that of the present

-- ~__-.---. -I_- ..--. -..--_


U.S. level. Finally, though, industrial growth is halted, the death rate rises as resources are depleted, pollution accumulates and food production declines. The population declines sometime near 2100.

The computerized models presented in the report on ‘Limits to Growth’ have, however, been questioned. There are some people who present a rather optimistic view of the future of the world. According to Julian Simon “there is no physical or economic reason why human resourcefulness and enterprise cannot forever continue to respond to impending shortages and existing problems with new expedients that, after an adjustment period, leave us better off than before the problem arose. Adding more people will cause us problems, but at the same time there will be more people to solve these problems and leave us with the bonus of lower costs and less scarcity in the long run. The bonus applies to such desirable resources as better health, more wilderness, cheaper energy, and a cleaner environment”.

References

Barney, 0. Gerard: The Global 2000 Report to the President - Entering the Twenty First Centwy. Washington, D.C. U.S. Printing Office, 1977.

Boughey, Arthur S: Ecology OfPopulations. New York, The Macmillan Company, 1973.

Brown, Lester R.: The Twenty-Ninth Day; accommodating human needs and numbers to the earth’s resources. New York, W.W. Norton, 1978.

Cole, H.S.D., et-al: Thinking about the Future- a critique of the limits togrowth. London, Chatto and Windus Ltd., 1973.

Commoner, Barry: The Closing Circle, Nature, Man and Technology. New York, Alfred A. &off, 1971.

Ehrlich, Paul R. et. al.: Eco-science, Resources and Environment. San Francisco. W.H. Freemen, 1977.

Frejka, Tomas: The Future of Population Growth. New York, John Wiley and Sons, 1973.

Hirsch, Fred: Social Limits to Growth. London, Routledge and Kegan Paul, 1978.

Mesaroric, Mihajlo and Edward Perstel: Mankind at the Turning Point; the second reporl to the Club of Rome. New York, E.P. Dutton, 1974.

Meadows, D.H. et. al.: The Limits to Growth, a report for the Club of Rome’s project on the predicament of mankind. New York, Universe Books, 1972.

Revelle, Roger et. al.: The Survival Equation. Boston, Mass. Houghton Mifflin Co., 1971.

Sharma, R. C.: Population, Resources, Environment and Quality of Life. Delhi, Dhanpat Rai & Sons, 1988.

Unesco: Teacher’s study guide on the biology of human population. Paris, Unesco Press, 1975.

United Nations, Department of International Economic and Social Affairs. World population prospects as assessed in 1980. New York, 1981.

Chapter 6

Impact of Human Activities on the Environment: Global Issues*

Environmental problems have not been uncommon phenomena where a development activity has been carried out. Human activity will give an impact on the environment in any case. These environmental problems have become serious sometimes and othertimes have not been so crucial. However, these environmental issues are tending to arise on a global scale. In other n words, these environmental problems have become problems not only for some specific countries but also for all the countries in the world. On the other hand, some of these problems assault developing countries rather than developed countries. Some human activities do not conclude in one country. Development of international trade on a global scale is also one of the reasons. Large scale industrial activity carried out without enough attention being paid to the environment is another cause of these problems. Following are some examples of these problems.

Ozone Layer Depletion

In 1974, Prof. Rolland presented his view on ozone layer depletion and possibility of its effects on people and ecosystem in nature. This problem was discussed at UNEP Governing Council 5 in 1977 and a Coordinating Committee for Ozone Layer (CCOL) was established. This was followed by the establishment of a working group for the protection of the ozone layer and led to the agreement of the International Convention for the Protection of Ozone Layer.

The problem of ozone layer depletion is now a major political concern of the world and a lot of activities are being carried out for its solution or mitigation.

Ozone and its Role

Ozone is a minor constituent of the atmosphere. If all the ozone in the atmosphere from ground level to a height of some 60 km could be assembled at the Earth’s surface, it would comprise a layer of gas only about 3 mm thick, weighing some 3 000 million tons. Most of the atmosphere’s ozone is seen between 10 and 50 km above the earth’s surface, which is called the stratosphere.

* Prepared by K. Onogawa. Deputy Director, United Nations Environment Programme, Regional Office for Asia and the Pacific., Bangkok.


In spite of this, life depends on the presence of ozone. Ozone has the ability to absorb ultraviolet radiation emitted by the sun up to wavelengths of about 320 nanometers (1 nanometre is a millionth of a millimetre, or 10e9 m). Ultraviolet wavelengths of 200-280 nm, known as UV-C, are lethal to human and living things but are more or less totally absorbed by atmospheric ozone.

Between 280 and 320 nm, ozone absorbs most, but not all, the radiation. This portion of the spectrum, known as UV-B, is lethal to many forms of life. Even at the low levels that currently reach the Earth, it causes eye damage and skin cancer in human.

Increased radiation at these wavelengths would be detrimental to human health and could lead to serious effects on the productivity of plants, including many domestic crops, and on marine algae and hence on fish production. Ultraviolet radiation above 320 nm, UV-A, is relatively harmless and little of it is absorbed by ozone. See Fig. 6.1.

Ozone thus acts as a kind of umbrella against the ultraviolet, shielding life on Earth from

500 600 wavelength (nanometres)

700 800 900

Figure 6.1. Solar radiation spans wavelengths rangingfrom about 100 to more than 3 000 nanometers (run) but much of it never reaches the Earth. The 280-320 nm band known as

UV-B which is only partially absorbed by ozone, causes sunburn, eye damage, skin cancer and slow plant growth.

4 uttra?liolet --t 4 visible light c - infrcsed b

t UV-C + WI-B t-W-A-+ almost harmless completely absorbed by ozone

an extremely harmful form of radiation.

Impact of Human Activities on the Environment 85

CFCs and Halons

What are CFCs and Halons and how are these used in our society? CFC (CFC-11) was invented in USA in 1928 by T. Midgley as a replacement for ammonium which was used in refrigeration at that time but later found unsafe. CFCwas considered to be completely harmless, poisonless and non-inflammable. Until 1950, CFC was used mainly for refrigerators and air-conditioners. They are now widely used in relation to our daily life as other types-of CFCs have been invented. CFCs are easily liquefied by compression and can dissolve many types of organic matter. CFCs have been used as the propelling agent for cosmetics, paints, etc. They have also been used as a foaming agent for polyurethane and as a cleaning agent for sophisti- cated electronic parts such as Integrated Circuits (ICs).

Table 6.1. CFCs and Halons Under Regulations by Montreal Protocol

HALON- 1

ODP : Relative Value of Ozone Depletion potential based on CFC-11

Reference: Technologies for Clorojluorocarbon Alternatives, 1989, Japan and Montreal Protocol on Sub- starlces that Deplete the Ozone Layer

Mechanism of Ozone Layer Depletion

CFCs are stable and cannot be easily decomposed. However, these CFCs are climbing up to the stratosphere through the troposphere - taking 10 or more years. In the stratosphere, CFCs are attacked by the radiation of UV and are decomposed, releasing atoms of chlorine. These chlorine atoms attack ozone molecules and destroy them. Some reactions to be considered occurring in the stratosphere are shown in Fig. 6.2.


Cl + 03 * Cl0 + 02 H +03 + OH+02

Cl0 + 0 - Cl + 02 OH +0 .H+02

03 + 0 - 202 03 +o -- 202

Cl + 03 - Cl0 + 02

Br +0 * BrO + 02 NO +03 + NO2 + 02

Cl0 + BrO - Cl + Br + 02 NOz+O l NO +02

203 + 0 ----- 302 03 + 0 . 202

Figure 6.2. Destruction of ozone

There are several types of CFCs as mentioned before and these CFCs are classified into the following three groups based on their molecular structures and behaviour in the atmosphere:

l PFC (Perfluorocarbons) or “Super-hard Fluorocarbons”. The molecules of PFCs are composed of fluorine and carbon. As the C-F bond is very strong, they are extremely stable against chemical attacks as well as to light and heat. They will not decompose even in the stratosphere, and they will photodegrade in the upper portion of atmosphere such as at altitudes above 70 km. Their life time is estimated to be as long as 1,000 years. They have no potential to deplete the ozone layer, but they might have an impact on the “green house effect”. Examples of this class are PFC-14, CF4, which are used as dry etchant in the electronics industry.

l CFC (Chlorofluorocarbons) or “Hard Fluorocarbons”. Chlorofluorocarbon molecules are composed of chlorine, fluorine and carbon. They are hardly decomposed in the troposphere, and gradually diffuse up to the stratosphere, taking about 10 years or more. The ozone layer is partly destroyed by CFCs. Most of the fluorocarbons now widely used belong to this class. Examples are CFC-11, -12, -113, -114 and -115.

l HFC (Hydrofluorocarbons) and HCFC (Hydrochlorofluorocarbons) or “Soft fluorocarbons”. Introduction of hydrogen atom(s) into the molecules of PFC or CFC is expected to make them “softer”. They will be decomposed much more easily than non-hydrogen-containing fluorocarbons in the atmosphere. HFCs and HCFCs are supposed to be degraded in the troposphere and do not survive to reach the stratosphere. Therefore, they have much less potential to destroy the ozone layer than CFCs. Most of the CFC alternatives being found so far are the compounds of this group. The ozone depletion potentials of HFC compounds are estimated to be zero because they have no chlorine atoms in the molecules.

Status of Ozone Layer Depletion

The total amount of ozone in the atmosphere has been measured from many different sites for many years, using different techniques. Of these measurements, the one made with an instrument known as the Dobson spectrophotometer is among the most useful. A statistical analysis of these data from all over the world reveals that the total ozone concentration, averaged over the whole globe, neither increased nor decreased over the period 1970-84.


There is, however, some evidence that the distribution of ozone in the atmosphere may be changing at other latitudes. A spectrophotometer at Halley Bay in the Antarctic has been used by the British Antarctic Survey to measure ozone levels almost above the South Pole every October since 1957. These measurements show that the total amount of ozone above the Antarctic has decreased by nearly 40 per cent since 1957, with most of the decrease occurring since the mid-1970s. Since 1979, these measurements have been confirmed by observations from satellites. Much more recently, satellite observations have shown that this damage to the ozone layer above the Antarctic may extend as far towards the equator as 45 degrees S, though the effect is far less pronounced than it is at the Antarctic. Clearly, there is a hole in the ozone layer above the South Pole, and the depth of this hole appears to be increasing. It occurs only during the Antarctic spring.

International Movements for Ozone Layer Protection

The Vienna Convention was signed by 46 countries and ratified by 39 countries as of 20 May 1989 and came into force on the 22 September 1988 and the Montreal Protocol came into force on the first of January 1989 as expected.

The Convention and the Protocol request parties to these to regulate their consumption and production of CFCs and Halon according to the following table:

Table 6.2. Regulated level of consumption and production of CFCs and Halons

Period 01/07/89-30/06/93 CFCs level of 1986

01/07/93-30/06/98 01/07/98-3OlOWB 80% of 1986 50% of 1986

Period Halons

OllO1/92- level of 1986

Referertce: Morttreal Protocol on Substames that Deplete the Ozone Layer

Further Activities

In addition to the regulations decided by the Montreal Protocol, the world is requesting more rapid and complete reduction of CFCs. These requests become more strict as time passes. The latest declaration which was made at Helsinki, Finland on 2 May 1989 on the occasion of the first meeting of the parties to the Vienna and the Montreal Protocol agreed:

l To phase out the production and the consumption of CFCs controlled by the Montreal Protocol as soon as possible but not later than the year 2ooO and for that purpose to tighten the timetable agreed upon in the Montreal Protocol;

o To both phase out halons and control and reduce other ozone-depleting substances which contribute significantly to.ozone depletion as soon as feasible;

l To facilitate the access of developing countries to relevant scientific information, research results and training and to seek to develop appropriate funding mechanisms to facilitate the transfer of technology and replacement of equipment at minimum cost to developing countries.

Following this declaration, industries are also tackling this problem with great effort. Some producers of CFCs have already declared that they will stop their production of CFCs by the

.---- ______ _-_ . -lll___


year 2000. There are also many CFC users that have declared that they will phase out the usage of CFCs by the year 2000 or even earlier.

New alternatives are required to satisfy the following requirements which are qualities of CFCs:

l Stable to heat and chemicals.

l Harmless, poisonless and non-inflammable.

. Easily reversible between liquid phase and gaseous phase.

l Oil solubility.

Development of alternatives to CFCs is being carried out by previous producers of CFCs and it is reported that some alternatives have been developed already. Some producers are providing these new alternatives to users and are asking them to attest to the results. New alternatives also require the users to develop new technology to be able to use these alternatives as the nature of these new substances is not exactly similar to the previous CFCs.

Other ideas are to employ CFC-free technologies for production and to recover the CFCs used in the process. Research work is also going on in these areas.

Another big discussion area is the problem of technology transfer to developing countries. Reflecting these requests, there is a grace period for developing countries in the Vienna Convention which allows the developing countries to delay the regulation for 10 years. In the Montreal Protocol, an exceptional measure was introduced to allow the parties to increase the production and consumption of designated CFCs if those are aimed at developing countries. As mentioned before, the Helsinki Declaration paid special attention to this point and agreed to seek to develop appropriate funding mechanisms to facilitate the transfer of technology to developing countries.

There is no argument that we need to protect the ozone layer for our health and both developed and developing countries must cooperate in solving this problem. For this purpose, it is necessary that developing countries be provided with possible aid to introduce these new ideas and technologies without much difficulty.

Climate Change

The best current estimate from theoretical models is that the global temperature will increase between 1.5 and 4.5 degrees C by the year 2030.

A temperature rise of this magnitude would have major effects on human society. The Earth’s average annual temperature has varied only rarely by more than 1 degree C over the past 10 000 years. Even during the last Ice Age, the average temperature of the Earth’s surface was only about 5 degrees C lower than it is now.

Such a warming of the Earth would probably produce much higher average temperatures in some areas - particularly the higher northern latitudes. Average rainfall would increase but many soils would become drier as a result of increased evaporation. Thermal expansion of the oceans would lead to a slow but steady rise in sea level, possibly followed after a century or so, by the melting of parts of the polar ice caps.


The effects on society would be widespread and would probably include crop reductions in marginal food producing areas. Sea level changes might lead to major migrations because much of the human population lives close to coastlines. The economic base of many countries and of international trade could undergo major transformations.

These considerations make international agreements to protect the ozone layer of paramount importance.

Status of Scientific Information

Trend ofCO2 concentration. CO2 is a major greenhouse gas like CFCs and methane. As shown in Figure 6.3, CO2 concentration record at the Mauna Loa, Hawaii shows continuous increase since 1958. According to this record, COa.has increased worldwide from 312-313 ppm in 1958 to 345 ppm in 1984.

NOAA/SCRIPPS CO2 AT MAUNA LOA 350 , , , , , , , ,, , 8, a I I I I a I I I I I I I I 1

310 ” ” ” ” ” I’ ’ ” It ” I’ ” It ’ 5859606162636465666768697071727374757677787980E1828384

YEAR

Figure 6.3. Trend in CO.2 concentration from 1958 to 1984

Other greenhouse gases. CO:! is not the only greenhouse gas. Figure 6.4 shows the contribution of respective greenhouse gases under the assumption of 3 degrees C temperature rise by the year 2030. As this figure shows, half the rise will be attributable to the increased concentration of carbon dioxide, the other half to increases in the concentrations of other greenhouse gases.

In the future it is expected that the portion attributed to the increase of other greenhouse gases will be increased. This is becauses the increase of CFCs (for example) attribute to the increase of temperature 20 000 times of that of CO2. In addition to this fact, CO2 is already abundant in the atmosphere and its increase will attribute to the temperature increase in proportion to the increase of its logarithm. However, as CFCs concentrations are rather low,


its increase will directly attribute to the increase of global temperature. It is expected that in the year 2000, the total contribution of greenhouse gases other than CO2 will be equal to that of CO2 and after that it will exceed that of CO2.

cumulative surface temperature rise PC)

0 1 2 3

carbon dioxi e

ozone (troposphere!

ozone (stratosphere)

CFCS

Figure 6.4. Other Greenhouse gases

Problems of Climatic Change

The effect of an infrared absorbing gas on temperature near the ground is commonly referred to as the “greenhouse effect”. Agreenhouse also has the important property of blocking heat and water vapour transport. The climatic consequences of the CO2 increase cannot be forecast precisely because the increase of atmospheric CO:! depends on an assumed energy growth rate, the proportion of energy derived from fossil fuels, and assumed strengths of the oceans and the biosphere as sinks for CO2. In addition, a predicted global warming for a given CO;! concentration must be based on our still limited ability to model a complex climate system with many non-linear processes. In a qualitative sense, the consequences to be expected from an increase of CO2 and other greenhouse gases in the atmosphere are as follows.


An increase in the air temperature in the troposphere, resulting in an increase of the water vapor content, and therefore a higher rate of transfer of latent heat from the equator to the poles. This can cause a weakening of the change of temperature with latitude, hence a weakening of the global circulation of the atmosphere. This influences temperature distributions and precipitation patterns, which determine agricultural productivity, water and energy supplies.

Sea Level Rise

Melting of Antarctica’s ice will cause an 80 metre rise in sea level. Melting of one per cent of the Antarctic ice cap (90 per cent of all the ice on the earth) will raise the sea level by 80 cm.

Several climatic change models suggest that one possible result of a global warming would be to increase the volume of the ice rather than decrease it. This is because there will be increased precipitation in the Antarctic as temperature rise, resulting in higher snowfall. Thus, if temperature increases by 3 degrees C and Antarctic precipitation rises 24 per cent, the volume of ice in the Antarctic would eventually increase by somewhat less than 1 per cent, leading to a 50 cm fall in sea level. (UNEP - GEMS, 1987)

International Movement for Climatic Change

One of the most fundamental meetings which are discussing global climate change issue is undoubtedly the Inter-Governmental Panel on Climate Change (IPCC) which is jointly established by UNEP and WMO. The IPCC met for the first time in Geneva in November 1988 with the participation of some 130 representatives from 37 governments and 16 international organizations. The establishment of the panel was endorsed by the United Nations General Assembly last December which requested the Secretary-General of WMO and the Executive Director of UNEP through the IPCC to immediately initiate action leading to a comprehensive review and recommendations with respect to the following:

l The state of knowledge of the science of climate and climatic change.

l Programmes and studies of the social and economic impacts of climate change, including global warming.

l Possible response strategies to delay, limit or mitigate the impacts of adverse climate change.

l The identification and possible strengthening of relevant existing international legal instruments having a bearing on climate.

l Elements for inclusion in a possible future international convention on climate.

Three working groups of IPCC which have specific working targets started their discussion in January and February 1989 and identified seventeen subject areas which will constitute the final report of the Panel. These three working groups are to examine, respectively: science aspects of climate change; environmental and socio-economic impacts; and development of response strategies.

IPCC is expected to finalize its first report by September/ October of next year. The panel’s work should be put before the Second World Climate Conference organized by WMO in cooperation with UNEP, Unesco, ICSU and probably others, towards the end of next year as well as the 45th United Nations General Assembly.


Perspective of Actions

The most obvious way of reducing the “greenhouse effect” problem is to use less energy. Only a decade ago, most authorities regarded this as an unworkable solution. Since then, two major rises in the price of oil have had a steadying effect on work energy consumption, and it has been shown that a four per cent annual increase in world energy consumption is neither necessary nor inevitable. In fact, burning less fossil fuel does not even mean using less energy. Energy could be used much more efficiently than it is now.

Acid Rain

History and Status of the Acid Rain Issue

Widespread damage to trees and crops is not only a late 1980s phenomenon but was seen in many places because of natural causes such as diseases, drought, heat, etc. It has also been recognized that air pollution can injure vegetation. Smelters, power plants and other large “point sources” of pollution have acutely damaged vegetation downwind; usually high levels of sulphur dioxide or fluoride were at fault.

For ten to twenty-five years now, an unusually large number of dead and damaged trees have been observed in Central Europe and the United States, though at first no obvious causes were identified. Visible symptoms first appeared in Germany in the late 1970s and by 1980 had spread to many European countries. In Europe, the symptoms developed more rapidly than in the United States, and now almost all important species at all elevations are in decline. (Mackenzie, 1988)

The problem is not only for the forest. It is reported that 1 750 lakes out of about 5 000 located at the south of Norway have been afflicted seriously and all fishes have become extinct. In Sweden 20 000 of the country’s 100 000 lakes are fishless, or considered about to become so. Acid rain also damages historical buildings and carvings in cities. This type of damage has been reported to be 7 billion dollars in a year only in United Kingdom. (UNEP/ GEMS, 1987)

The latest information presented at the Sofia meeting (31 October to 4 November 1988, Bulgaria) is that acid surface waters are now found in Belgium, Czechoslovakia, Finland, the FRG, Italy, the Netherlands, Norway, Sweden and the United States. Water acidification is also known to be a problem in Austria, Canada, Denmark, the GDR, Poland and the UK.

As regards forests, a survey carried out in 1987 in 22 European countries showed that only one country (Ireland) remained without forest damange. In three countries (Bulgaria, Hungary and Italy), damage was rated as low, i.e. less than 30 per cent of trees defoliated. In 10 countries, the intensity of damage was rated as severe, i.e. more than 50 per cent of all trees were affected by defoliation. While overall damage to needle trees decreased slightly, there was a substantial increase (between 2 and 20 per cent) in damage to broad-leafed trees during 1987. (UNEP/ GEMS, 1987)

Figure 6.5 shows the status of acid rainfall in Europe and North America.


Jan 1978 - Dee 1982 1982

Figure 6.5. pH Values of Rainfall in Europe and Norlh America

International Movement

There are some measures to mitigate acid rain. Application of great quantities of lime to lakes and forests is one. Giving plenty of fertilizers to forests is another. However, the most simple and ultimate solution of this problem is to control the emission of pollutants.

If the occurrence of this problem is limited to the borders of one country, it will bc controlled by the establishment of new regulating laws. However, as shown in Figure 6.5, this is usually a transboundary problem. Because of this, some international agreements have been made to control the emission in the region. The most famous one is the Helsinki Protocol which aims to decrease the SO2 emission to 70 per cent of 1980 levels by the year 1995. The Sofia session mentioned above reported that total emissions of sulphur dioxide in the ECE region as a whole have indeed gone down more than 15 per cent from 80.7 million tons in 1980 to 68.3 million tons in 1986. (Environmental Association of Japan, 1988 and UNEP, 1988)

The same problem at the border of USA and Canada also brought these two countries together to enter into a control agreement in 1980.

Another agreement was arranged for NOx emissions. In November 1988, the Executive Body for the Convention on Long-range Transboundary Air Pollution held its 6th session in Sofia, Bulgaria. Its most significant achievement was the signing by 25 countries of a new


protocol concerning the control of emissions of nitrogen oxides (NOx) or their transboundary fluxes, with a package of internationally agreed abatement measures starting with a freeze of emissions from 1994. (UNEP, Regional Bulletin for Europe, Dec. 1988)

Transboundary Movement of Hazardous Wastes

It is virtually unavoidable that undesirable by-products are generated through the production process of many human activities. In a broad sense, air pollution and waler pollution are also the same types of by-products and are included in the category ofwastes. These by-products are sometimes not only unnecessary but also hazardous for human health and the ecosystem. In developed countries, it is usual that hazardous wastes and their way of treatment and disposal are clearly designated.

However, the cost of implementing these standards is considerable. As the people’s concern about environment develops, the treatment and disposal costs become more expensive year by year. In addition to the problem of cost, it has become very difficult to get a consensus of people living around the site to agree to its designation as a final disposal site for hazardous wastes. Everybody agrees on the necessity of treatment and disposal of these hazardous wastes but no one allows the process to go on in their own backyard. This causes the problem of transboundary movement of hazardous wastes, where a disposal site unfettered by strict regulations and strong public opposition is sought. Some of the major movements along these lines take place between USAand Mexico, Europe and Africa and Western Europe and Eastern Europe.

To control these problems, the EC established guidelines to control these movements in 1984 which were later adopted by USA in 1986 and by OECD in 1989.

UNEP also drew up the Cairo Guideline in June 1987 which shows what types of wastes should be considered to be hazardous, how they should be controlled and what procedures should be followed. Based on this Cairo Guideline, the Base1 Convention was established in March 1989. This was called the agreement on Transboundary Movements of Hazardous Wastes and Their Disposal.

This convention will ban the export of hazardous wastes to countries which are not equipped with proper disposal facilities. The Convention, which by now has been signed by 34 states, is the fruit of 18 months of negotiations to curb the dumping of the West’s waste in the Third World.

Deforestation

Status of Degradation of Tropical Forests

Tropical forests are very unevenly distributed among the developing countries. If both closed and open tropical forests (those without a continuous canopy but with one that covers more than 10 per cent of the ground) are included, Brazil has 26.5 per cent of the world total, Zaire 9.2 per cent and Indonesia 6.1 per cent. Peru, Angola, Bolivia and India each has about 3 per cent. The rest is distributed among some 70 other tropical countries.

Until the 1980s no one knew with any accuracy how fast tropical forests were disappearing. A joint effort by UNEP and’FA0 made a systematic study of the problem: their conclusions


were that closed forest was disappearing at 7.5 million hectares a year and open forest at 3.8 million hectares a year. In total more than 11 million hectares of tropical forests - an area almost as large as Greece are lost every year. This result was published in 1981 and it is now 8 years old. UNEP and FA0 are preparing to revise this information.

Causes of Deforestation

There are many reasons for the causes of tropical deforestation. The need for fuelwood, for example, leads mainly to the degradation of open forests and plays little part in the destruction of closed forests. Even so, the amount of timber extracted for fuelwood and charcoal is large - roughly eight times as much as is extracted from logging.

Logging itself is not that destructive if carried out efficiently; however, it rarely is. Even if only one tree among 20 is taken, cutting that one tree often damages others. Furthermore, logging often requires new roads to be made in previously inaccessible areas. This often leads to further, more serious degradation. New roads open up the forest to new settlers. Analysis of the data shows that as much as 55 per cent of the forest that is logged over eventually becomes deforested.

The major cause of deforestation is the need to expand agricultural land. But blame should not be laid at the door of shifting agricuture itself. Small strips of forest can be cleared, burnt, planted and left to return to natural forest again provided the fallow period is long enough. In many places it no longer is. It is estimated that shifting agriculture now accounts for 70 per cent of deforestation in Africa, 50 per cent in Asia and 35 per cent in the Americas.

The impact of deforestation is not only the loss of the tropical forest itself. As Figure 6.6 shows, the benefits of forests are broad. The existence of tropical forest supports subsistence needs for human activity, works to protect the environment and conserve the biological diversity.

Half the world’s species are to be found in tropical forests. IUCN states that between 74 and 96 per cent of biological species on the earth could be found in tropical zones, and, in particular, tropical forests are home to 40 per cent of all species.

Figure 4.6. Benefits of forests.

-.. ___.. --. .-.... -.-_-__


References

Environmental Association of Japan. Think About Global Scale Air Pollution (in Japanese Chikyuu Kibo no Taikiosen wo Kangaeru). Sept. 1988, Japan.

Ishikawa Nobuo. Technologies for Chloro Fluorocarbon Alternatives. Asia and Pacific Ozone Layer Protection Seminar. May 1989. Tokyo Japan.

Mackenzie Jr. J. etal. Ill winds -Airborne Pollutions Toll on Trees and Crops. World Resources Institutes. Sept 1988, USA.

Montreal Protocol on Substances that Deplete the Ozone Layer.

NHR Book. Protection of Ozone Layer (in Japanese Ozone - sou wo Mamoru) 1989, Japan.

Pueschel. R.F. (1986) Man and the Composition of the Atmosphere. WMOI UNEP.

UNEP/ GEMS. The Greenhouse Gases. Environment Library No. 1. UNEP 1987, Kenya.

UNEP/ GEMS. The Ozone Layer. Enviroment Library No.2. UNEP 1987, Kenya.

UNEP/ GEMS. The Disappearing Forest. Environment Library No. 3. UNEP 1987, Kenya.

UNEP Regional Bulletin for Europe. Dec. 1988.

Chapter 7

Pollution - Its Effects on Man and the Ecosystem*

Many human activities inevitably cause impacts on the environment. Although impacts have usually been absorbed by nature without much ill effect, some problems have been caused when these activities are carried out with too much intensity in a limited area over a short period of time. These environmental problems have sometimes caused serious health-related problems to the people. The following are some typical examples of these problems.

Water Pollution

Water pollution has been caused by almost all human activities. In addition to industrial, agricultural, mining and commercial activities, daily human activities have also become the cause of this problem, particularly in big cities. This pollution has caused some problems not only on the environment but also on human health. Most typical examples of health effects on human caused by water pollution are Minamata Disease and Itai Itai Disease, both of which were reported in Japan in the 1950s and 1960s.

Minamata Disease

Minamata Disease was first discovered in 1956 around the harbour of Minamata in Kumamoto Prefecture, on the west side of Japan and was named after the harbour. Although the specific case at Minamata has become famous because of its name, there is another area affected by Minamata Disease which is called the second Minamata Disease. In 1965, the second Minamata Disease was found along the Agano River in Niigata Prefecture. It was concluded after the surveillance carried out by the government that the methyl mercury discharged from factories of Chisso Co. and Syouwa Denko Co. respectively was accumulated in fishes and shellfishes first, and the people who ate these polluted fishes continuously were affected by this disease. This is the reason the Minamata Disease has been found more frequently in the families of fishermen and those fond of eating fish.

As of December 1988,2 901 persons have been officially considered to be victims of this disease and 1 787 of them are now receiving medical treatment and compensation.

* Prepared by K. Onogawa, Deputy Director, United Nations Environment Programme, Regional Office for Asia and the Pacific, Bangkok.


ltai ltai Disease

Itai Itai Disease was reported to the academy in 1955 as a strange disease whose cause was not understood. In 1968, the Ministry of Health and Welfare concluded that chronic poisoning by cadmium caused a kidney problem and the softening of bones. Some other causes such as shortage of calcium could have also brought about this disease. In this report, the effluent water from Kamioka Mining Factory of Mitsui Metal Industry was considered to be the reason for this.

By the end of December 1988,124 patients had been declared victims of this disease and 17 people are still receiving medical care and compensation as of that date.

Other Toxic Effects

Water pollution also affects animals and plants which are living in the hydrosphere. Heavy metals and chemicals are not easily decomposed. They are accumulated in sediment or in plants, or in small plankton first and become accumulated in bigger fishes through the food chain mechanism. There is a limited number of reports in ASEAN countries as regards the status of these substances in fishes, shellfishes and seaweeds as well as the established standards to clarify the safety of those polluted crops. However, some activities have been carried out in some countries under international cooperative programmes. Mussel Watch Project is one of these programmes.

There is also very little reliable information on the levels of heavy metals in marine sediments in the Southeast Asian region. Although some results have been reported, they are usually measured at potentially high pollution areas and very seldom at ordinary or non-polluted areas.

The status of pollution in some ASEAN members countries are shown in Tables 7.1, 7.2 and 7.3. (AMBIO. Vol. XVII. No. 1, 1988)

Table 7.1. Concentrations of heavy metals in water at Jakarta Bay and at the Upper Gulf of Thailand (1978) unit: ugIL

Jakarta Bay Upper Gulf of Thailand Min. MaX. Min. Max.

Japan (1987)* Standard Over ratio

Hg 2.8 35.2 total 1.54 12.0 0.5 5/28665 dissolved 0.08 0.22

Pb 40.0 500.0 344.00 560.0 100.0 8125980 Cd 5.0 450.0 47.6 89.3 10.0 14125893

* Japanese over ratio means the number of samples which exceeds environmental quality standards over total number of samples which were analyzed for respective substances. These numbers are for all samples including rivers, lakes and coastal seas.

Pollution 99

Table 7.2. Heavy metals in sediments of Jakarta Bay, August 1982

Hg Cd Cr co cu Mn 0.093-3.568 < 0.5 4.9-32.5 12.2-17.5 11.8-82.9 927-1858

Pb Ni Zn 9.0-438 4.8-15.4 75.8-79.8 unit: mg/kg

There is a new tendency in the measurement of heavy metal concentration in commercially important marine biota. In Thailand, measurements of selected trace metals in green mussels, oysters, clams and scallops were carried out as Thailand’s contribution to the Global Mussel Watch Programme. In addition to this, cadmium, chromium, copper, iron, lead, nickel, mercury and zinc levels were determined in four commercial species of bivalves. The results indicated no threats to public health from these species.

In the Philippines, baseline monitoring of metals in marine organisms began in 1972. In Indonesia and Malaysia, similar studies have been carried out and have shown that heavy metals do not seem to pose a problem in those countries.

Table 7.3. Ranges of heavy-metals concentrations in bivalves in the Philippines (unit: uglg, wet weight)

Oyster Mussels

Cd CU

0.065-0.180 14.87-42.00 0.045-0.400 2.38- 5.00

Pb Hg 0.037-0.161 0.057-0.073 0.078-0.122 0.038-0.093

Pollution by Chemicals

Some tens of thousands of chemicals are being produced and used in our society. These chemicals are discharged into the environment through the processes of their production, marketing, usage and disposal, causing environmental pollution. Some of these chemicals have a tendency to remain in the environment for a long time even if the usage of those chemicals is stopped. This tendency is remarkable in living animals in connection with the so-called food chain. Table 7.4 shows the detection ratios of some well known chemicals whose use has been prohibited in Japan. Table 7.5 shows the results of similar studies in Malaysia.

It is difficult to establish the permissible or desirable standards for specific crops. Estab- lishment of standards is considerably affected by the level of consumption of these by specific people who will consume these crops and it cannot be discussed independently from the lifestyle of these people.

Following are examples from Japan and Malaysia on mercury and PCBs, both of which have caused significant environmental problems.


Table 7.4. Detection ratios of major toxic chemicals in Japan (1986)

Fish Detected/Samples Ratio

Shellfish Detected/Samples Ratio

PCBs (1972) 42160 70% 10120 50%

HCB (1979) 13160 22% 0120 0%

DIELDRIN (1981) 25160 42% 10120 50%

PP’ - DDT (1981) 39160 65% 15120 75%

ALPHA-HCH (1971) 33160 56% 10/20 50%

Figure in ( ) shows the year of prohibition from their usage.

Sources: Environmental Science Dictionary (in Japanese), Tokyo, Kagaku Dojin, 1985, Japan.8

Table 7.5. Chlorinated hydrocarbons in samples from Malaysia (in uglkg net weight)

Fish Shellfish

Lindane Dieldrin DDT PCBs 1-12 < l-5 3-16 20-40 3-8 l-5 26.50 27-44

Source: Heavy Metals and other Non-Oil Pollutants in SoutheastAsia, Manuwadi Hungspreugs, AMBIO, Volume XVII. Number 1, 1988.

Table 7.6. Standards for Mercury and PCBs for fiihes in Japan (including shellfish)

Methyl Hg Total Hg PCBs PCBs

0.3 mglkg 0.4 mg/kg 0.5 mg/kg (for deep sea fish) 3.0 mg/kg (for coastal fish)

Accidental Water Pollution

Accidental water pollution brings serious environmental problems. An accident at Basel, Switzerland, in the upper stretches of the Rhine River in 1986, caused crucial environmental degradation in the whole Rhine River. The oil leakage accident at Mizushima, Japan in 1974 cost more than 20 billion yen (US$lSO M)in mitigation activities and compensation for fishermen.

Air Pollution

Air pollution is another major environmental problem which may cause impacts on human health and the ecosystem. Major sources of air pollution are industries, automobiles and consumption of domestic fuels. Depending on the characteristics of specific cities, the most essential pollution source differs from city to city. Following are the major pollutants discharged by each pollution source.

Pollorion 101

Table 7.7. Major pollutants discharged by each pollution source

Source Major Polluants

Industry Automobiles Domestic fuel (coal)

SO2, NO2, SPM NO2, CO, HC, Pb SPM, CO, SO2

There are some typical air pollution problems in history. One of the mostwell known cases was the London Smog in 1952 in London, UK It it said that between 5 and 9 of December 1952 about 4 000 people died, principally among elder, infants and people suffering from respiratory diseases because of the formation of smog caused by the use of coal for home heating.

Another type of smog called Photochemical Smog was reported in the 1940s in Los Angeles, USA. Irritation of the sensitive membranes such as eyes, throat, nose, etc. is the main symptom of this smog. The symptoms are observed at mid daytime when the sky is clear and the sunlight’s radiation is abundant. From Los Angeles, it is reported that this photochemical reaction is also causing rubber to crack.

Chronic pulmonary disease was reported in Yokkaichi, Mie Prefecture in Japan. In Yokkaichi City, large-scale oil complexes started operating in 1960; and since 1961 a number of patients started to complain of asthma-like symptoms - later to be known as Yokkaichi Asthma. The correlation between SO2 concentration and occurrence of symptoms is established. The fact that many patients observed were living downstream of factories and many of these patients later recovered from the symptoms or improved their health when they moved out of the city, made the Yokkaichi Court declare that this disease was caused by the oil factories. Because of this court pronouncement, a new Pollution-Related Health Damage Compensation Law was enacted opening up for the victims to be refunded for their medical expenses as well as to be compensated for their losses in response to the degree of their diseases. (Environmental Science Dictionary, 1985)

Effects on plants have been recognized since long time ago. The most frequently encountered phytotoxicants are sulphur dioxide, hydrogen fluoride, chlorine, ammonia andothers. There are two types of injury to plants, one is visible and the other is invisible. The nature of the visible injury varies with the pollutant, but is usually some form of chlorotic marking (disappearance of green color), banding or silvering or bronzing of the underside of the leaf. However, as a result of direct exposure to smoke which contains a high concentration of SO2, it is reported that in the 1880s all trees in the mountain near the Ashio Smelting Factory in Japan died. It is normally possible to distinguish between acute injury which becomes obvious within a few hours of exposure to high pollution levels, and chronic injury, which develops slowly as a result of continuous exposure to low concentrations. In addition to visible injury, there has been much speculation about “invisible injury” or growth retardation of plants as a result of air pollution. However, because so many factors affect.growth it is very difficult to isolate this type of air pollution effect. (Atkins Research Development, Feb. 1979).

Some typical effects of pollutants on human health are shown in Table 7.8.

-. -_-__ _


Table 7.8. Effects of Pollutants on Human Health

Pollutants Effects

Sulphur dioxide Aggravation of respiratory diseases, e.g. asthma and

chronic bronchitis

Impairment of pulmonary function

Irritation of eyes and respiratory tract

Leaf injury and reduced growth in plants

Corrosion of metals

Deterioration of building materials, textiles

Particulate matter Direct toxic effects or aggravation of effects of gaseous

Oxidants

Hydrocarbons

Carbon monoxide

Nitrogen dioxide

Lead

pollutants

Increase in chronic respiratory diseases

Impairment of visibility

Alteration in incident sunlight

Interference with plant photosynthesis

Soils surfaces and materials

Abrasion of building materials and textiles

Aggravation of emphysema, asthma and bronchitis

Impairment of cardiopulmonary function

Leaf injury and reduced growth of plants

Deterioration of rubber, textiles

Contribution to formation of photochemical oxidants

Sensory irritation

Increased general mortality and coronary mortality rates

Reduced tolerance for exercise

Impairment of mental function

Aggravation of respiratory and cardiovascular illnesses

Discolours atmosphere

Damage to vegetation

Fading of paints and dyes

Increased storage in body

Impairment of haemoglobin and porphyrin synthesis

Impairment of learning and intelligence in school

children

Lethal to animals eating contaminated feed

Reference:A Monograph on Air-Pollution - Its Dispersion and Effects, Atkins Research Develop- ment, February 1979, England.

-. _. .,,., ._

Pollution 703

Agricultural Chemicals: Fertilizers and Pesticides

The ever-increasing demand for food and cash crops has led not only to the proliferation of large and small irrigation schemes, but to the increasing use of agrochemicals - mineral fertilizers to improve soils; pesticides to control insects, arachnids, rodents, fungi and weeds; as well as plant growth regulators, hormones etc. The use of agrochemicals is relatively recent and there are still examples of communities that practice agriculture and obtain high yields without the use of agrochemicals. In general, however, agricultural development is now unthinkable without adequate inputs of agrochemicals. Irrational use of these, however, is beginning in countries that have not yet developed the technical means to monitor and control the distribution and rational use of these products. (UNEP, The State of Environment, 1986).

Fertilizers

The worldwide consumption of the major categories of fertilizers (nitrogen, phosphorus and potassium compounds) rose by about 10 per cent per year between 1980/1981 and 1983/1984. Both levels of consumption per hectare of agricultural land and rates of increase have been uneven, however, with both generally very low in South and Central America and in Africa, higher but nearly steady consumption levels in North America, sharply increasing in Asia and very high in Europe.

Mineral fertilizer consumption in this region between 1976 and 1986 is shown in Tables 7.9 and 7.10.

Table 7.9. Mineral fertilizer consumption

Country 1976 1983 1984 1985 1986 Growth Rate/Year

Indonesia 493 1516 1874 1959 2080 15.6% Malaysia 299 566 566 611 687 8.0% Philippines 269 359 262 283 390 1.6% Thailand 237 485 465 412 465 7.0% Australia 981 1178 1230 1155 1199 1.7% Japan 2086 2098 2105 2034 2021 -0.6%

Unit: 1000 tons

Source: Selected Indicators of Food and Agkulture Development in Asia - Pacific Region, 1977-87, Regional Office for Asia and the Pacific, Food and Agriculture Organization of the United Nations, Thailand, 1988.


Table 7.10. Mineral Fertilizer Consumption per ha of Agricultural Land

Country 1976 1983 1984 1985 1986 Growth Rate/Year

Indonesia 25.4 74.6 89.9 93.8 98.0 14.5% Malaysia 70.3 130.4 127.8 139.9 157.0 8.4% Philippines 36.1 45.6 33.3 35.9 49.2 3.1% Thailand 14.0 25.2 24.1 20.7 23.4 5.3% Australia 23.2 26.2 25.6 23.8 24.7 0.6% Japan 414.7 436.5 440.4 427.5 427.1 0.3%

Unit: kg/ha

Source: Ibid.

Little is known of the direct effects of the intensive use of fertilizers on health; probably because they are generally insignificant. Indirectly, run-off from land treated with chemical fertilizers, particularly phosphates, contributes to the eutrophication of fresh and ocean waters. Eutrophication induces changes in the species composition of the aquatic fauna and effects on man may vary from the production of noxious odour to exposure to toxins arising from the multiplication of certain phytoplankton organisms. The consumption of shellfish contaminated with certain types of toxin-containing dinoflagellates has led to severe outbreaks of paralytic shellfish poisoning. (UNEP, The State of the Environment, 1986).

Pesticides

Coupled with the use of fertilizers, the use of modern pesticides, originally introduced to control vector-borne diseases (malaria and typhus), has been an essential contributor to increases in crop yields throughout the world. In addition, pesticides have played a major role in reducing pre- and post-harvest food losses. In general, pesticides have been one of the major weapons in the struggle against food shortages. Ninety per cent of the pesticide production is used for agricultural purposes (primarily on maize, cotton and rice) and most for health protection. The success of pesticides, however, has exacted a price in terms of side effects, some of them involving human health. Perhaps the most dramatic of these has been the increase in the number of strains and species resistant to certain pesticides and the now frequent emergence of multiple resistance. Among other things, this has allowed a dramatic return of malaria cases in numbers that are close to those recorded prior to the use of DDT, a return that is also partly due to a relaxation of the efforts in the fight against mosquitoes and to the increased resistance of the malaria agents to chemotherapy.

In the past, spraying pesticides on food crops also caused levels of persistent (organochlorine) pesticides to rise in foodstuffs in certain countries, with unknown effects on health, particularly in children who may be highly exposed through consumption of mother’s milk. A rcccnt case of major cow milk contamination has been reported from the United States. It led to the destruction of large batches of milk.

The application of pesticides, and particularly of herbicides, may result in fish kills with potential consequences on the food supply of those people who traditionally derive their main source of protein from fish. In addition, the presence of highly toxic dioxin in some herbicides

Pollution 105

used on a large scale has, in some areas, been the cause of heated controversy between foresters and health authorities.

Although not all cases of pesticide poisonings can be described as environmental in nature, no review of environment and health would be complete without mentioning that the use or availability of organo-phosphorous and carbamate insecticides and acaricides has been accompanied by an increasing number of cases of chronic occupational poisoning among field workers, and of acute accidental poisoning, both among field workers and the public. Reliable statistics are lacking; however, the most recent estimates suggest that the number of acute pesticide poisonings is of the order of one million cases per year with an overall fatality rate of between 0.5 and 2.0 per cent. While the figures represent only 4.0 per cent of fatalities due to all types of unintentional acute poisonings worldwide, it must be emphasized that most of them are avoidable and that their geographical distribution is likely to be un-uniform, with the greatest number of cases in developing countries making intensive use of the pesticide products on cash crops without observing the necessary safety precautions. No estimates of the possibly much larger number of cases of chronic pesticide exposures and their long-term significance are available.

The negative aspects of pesticides have resulted in an accelerated search by industry for new, but often more expensive, active chemicals that are less toxic to non-target organisms, including man, and less persistent in the environment. These aspects have also made clear the need to use pesticides, and especially insecticides, more sparingly by relying on ultra-low volume formulations and controlled droplet application of concentrated formulations. These are not without their risks to the workers when the hand-held equipment is not properly maintained.

In this regard, with the cooperation of the Thai government and NGOs, UNEPLROAP carried out a series of training workshops in five selected provinces in Thailand in early 1989. The purpose was to create awareness among the rural population of the harmful effects of hazardous materials, particularly pesticides, and to assist rural women leaders in gaining knowledge about the safe handling of hazardous materials. The targeted populations in the workshop were housewives, leaders, sub-district local news disseminators and volunteer teachers of the Non-Formal Education Department. About 300 leaders and others have attended this series of workshops. The material which has been used was written in local language to facilitate the participants’ understanding but it is now being translated into English and will be available in the near future to accomodate the same type of activities in other countries. (UNEPIROAP Newsletter, January - March 1989).

Disposal of Chemicals

Some of the typical examples of chemicals notorious for their toxicity and difficulty of disposal are PCBs. PCBs have been used widely for transformers, capacitors, non-carbon copy papers, etc. Their production and usage was stopped after a report of their toxic effect although limited production was continued in some countries for some specified purposes, mainly for defense industries.

Although production and usage was stopped, people was still concerned about the disposal particularly when a report stated that PCDDs (dioxines) were reported to be formated as waste PCBs were incinerated. The only reliable and feasible way of disposal of PCBs is high temperature incineration. However, because of this report construction or operation of PCBs incinerators has become increasingly difficult. People do not favour incinerators near their living


place although they admit the necessity to dispose of waste PCBs. From a technical point of view, incineration is proven safe if carried out at temperatures high enough and with adequate residence time in the chamber. Tests reported no detection of PCDDs at 1200 degrees Celsius, while some PCDDs were detected at 700 to 800 degrees Celsius. In Japan 5 500 tons of waste liquid PCBs which have been recovered from all over Japan is planned to be incenerated at 1400 plus or minus 75 degrees Celsius with a residence time of more than 1.5 seonds.

PCDDs (dioxines)

Dioxines have become famous as they were found in the defoliant which was used in the Vietnam War and considered to be a strong mutagen. They have never been produced intentionally but were formed as one of impurities when 2,4,5-trichlorophenoxyacetic acid was produced and used as a defoliant in the Vietnam War. There are 75 types of isomers and 2,3,7,8-TCDD is known as the strongest mutagenic TCDD among all isomers. TCDDs have been detected at the accident site of ICMESA, Sebeso, Italy which was producing 2,4,5-T, and at Timesbeach, USA where chemical wastes have been disposed and soil pollution was reported, and in the ash of domestic waste incineration facilities. The dioxin strategy which was prepared by US EPA in November 1983 for the treatment of TCDDs and polluted land is famous.

Marine Pollution

One of the most common phenomena of sea pollution in relation to discharge of waste water is the eutrophication which leads to the formation of Red Tide. Like the case of acidification in lakes, this was first reported in places such as Re-Man, a closed lake in Switzerland. As a matter of transmigration, eutrophication followed by change to wet land is inevitable for a lake. However, the artificial and rapid eutrophication makes the interval of this process short and raises ecological problems. In the sea, this phenomena appears as red tide which now occurs throughout the world. Aquaculture is seriously damaged by this red tide and if the status is particularly bad living animals in the ordinary sea area are also affected.

In ASEAN member countries, this red tide is reported widely. For example, in Philippines, the first major red tide outbreak was reported in 1983 in Maqueda and Villareal Bays. In Indonesia, red tide itself has been considered a seasonal phenomena which occurs 5 to 7 months after the rainy season in Jakarta Bay. However, it was not until July 1986 that a fish poisoning by this red tide was reported in the said bay. The investigation on red tide in the Gulf of Thailand indicates that the red tide always occurs in February to May and that it caused extensive damage to fish farms on the eastern coast in 1983.

In other Asian and Pacific countries, Hong Kong reports the rapid increase of the number of occurrences of red tide in its harbour with effects on fishes. In Korea, it is reported that red tides are nowadays characterized by their large scale, wide distribution, long period of duration and high density. Australia, China and Taiwan also report occurrences of red tide.

In Japan, continuous studies have been carried out throughout the country. In particular the Seto Inland Sea, located between Honshu and Shikoku on the west side of Japan, is famous for the occurrence of red tides. This area is a typical archipelago and designated as a national park. A study in this area shows some interrelations between pollution load and occurrence of red tide over the past 15 years.

Pollution 107

The effects of eutrophication are felt after the passing of the short term red tide. Although the status of inflow and the condition of sea water will be improved after the introduction of discharge regulation, the sediment still remains at the site. In the second stage, an increase of sediment, usually containing a great amount of organic substances, starts and consumes the dissolved oxygen. This process initially makes the bottom water layer less aerobic and later turns it to an anaerobic condition. It is reported in Tokyo Bay that this sediment causes another type of problem which is called Blue Tide. In a coastal area where thermal strata are formulated, the bottom layer is kept calm through the season and this condition leads to that layer taking on an anaerobic condition because of the oxidation of sedimented organic substances. This bottom layer sometimes comes up to the surface when seasonal winds blow and affects the ecosystems in that area.

Activities of UNEP

IRPTC

Interest in setting up an international system to collect, validate and exhange information on hazardous chemicals started to grow during the sixties. In 1972, the United Nations Conference on the Human Environment, held in Stockholm, recommended the setting up of a centralized register of data on chemicals likely to enter and damage the environment. Two years later (1974) the Governing Council of UNEP decided to establish both a chemicals register and a global network for exchange of the information their register would contain. The main objectives agreed by the UNEP Governing Council are as follows:

l To make the data on chemicals readily available to those who need it;

l To locate and draw attention to the major gaps in the available information and encourage research to fill thpse gaps;

l To identify the potential hazards of using chemicals and make people aware of them;

l To assemble information on existing policies for control and regulation of hazardous chemicals at national, regional and global levels.

In 1976 a central unit called the Programme Activity Centre was set up in Geneva for the register. Its major tasks are to collect, store and disseminate data on chemicals, and to operate a global network for information exchange.

The information collected is called the International Register of Potentially Toxic Chemi- cals (IRPTC) and can be grouped into two major categories: information on chemicals; and informationonchemical regulation, includingaccidentsand incidents involvingchemicalswhich have led to official inquiries.

Regional Seas Programme

The Oceans and Coastal Areas Programme Activity Centre (OCA/PAC) is implementing sea water quality related programmes in UNEP. OCA/PAC was originally established in 1977 at Geneva as the Regional Seas Activity Centre and renamed and reorganized in 1985 as the Oceans and Coastal Areas Programme Activity Centre. OCA/PAC is in charge of both action


plans of the regional seas programme and the action plan for the reservation conservation, management and utilization of marine mammals.

Under the coordination of OCALPAC, the Regional Seas Programme was started in 1984 and now 10 regional seas programmes are being implemented involving 120 coastal states. Fig. 7.1 shows the areas covered by the 10 Regional Seas Programmes.

Figure 7.1. The regional seas

In Asia and the Pacific Region, we have three regional seas action plans:

l South Asian Seas Action Plan (SAS)

. East Asian Seas Action Plan (EAS)

l South Pacific Action Plan (SPREP)

In addition to these three action plans, another regional plan is expected - the North West Pacific Seas Action Plan. In this action plan, the Sea of Japan, the East China Sea and the Yellow Sea will be covered involving China, South Korea, North Korea, Japan and USSR.

An example of the regional seas action plan is the East Asian Seas Action Plan (EAS) which, as of 1988, has eight projects as shown below.

1. Research on oil and oil dispersant toxicity in the region.

2. Study on coral resources and the effects of pollutants and other destructive factors on coral communities and related fisheries in the region.

3. Study of the maritime meteorological phenomena and oceanographic features of the region.

4. Survey and monitoring of oil pollution and development of a national coordinating mechanism for the management and establishment of a regional data exchange system.

Pollution 709

5. Assessment of concentration and scientific support programme for oil spill contingen- cy planning.

6. Implementation of a technical and scientific support programme for oil spill contin- gency planning.

7. Development of management plans for endangered coastal and marine living resources in East Asia (training phase).

8. Assessment of land-based urban, industrial and agricultural sources of pollution, their environmental impact and development of recommendations for possible control measures.

Pollution Control Mechanism

The usual strategy to control pollution is the establishment of standards for the environmental condition and the introduction of regulation standards. Although these ideas have been introduced already in almost all countries, the actual implementation of these is far below a satisfactory level. In addition to institutional problems, the lack of some key elements has been pointed out. These key elements are: sufficient facilities; trained persons; running budgets; and the appropriate regulation. It is not rare to find that all of these elements are below the satisfactory level in developing countries and that proper management or maintenance of pollution control facilities cannot be expected in the private sector.

In the government sector, a shortage of these key elements appears as well as the lack of reliable information on the environment. Without correct information or data on various components of environment, it is virtually impossible to establish the goal of environmental protection, to evaluate the results of regulations, and to discuss further activities in the management of environment. Consolidation of environmental information is the most crucial requirement for environmental management.

For this reason, monitoring of the environment is most essential for any further activities. Water is the environmental indicator on which monitoring is most frequently carried out. However, this process is still facing the following problems:

l Shortage of number of monitoring points;

l Lack of continuous monitoring;

l Definite lack of continuous monitoring of hazardous materials, heavy metals, chemicals;

l Lack of speedy analysis;

l Low reliability of data.

To improve these conditions, greater budgets will inevitably be introduced for facilities, staff and running costs. Shortage of one of these essential elements results in unsatisfactory outputs. Although the problems of inadequate facilities and operational expenses can be rather easily solved by a rapid increase in budgets, trained staff cannot be secured easily. Staff training is lacking both in terms of quality and quantity.


The most practical solution for this problem is the establishment of a standing national training centre for the environment with lecture courses for each respective environmental subject. Two types of training should be takesn care of in this centre, namely technical and administrative training.

As the materialization of this kind of centre needs experience and budget, it is useful to get international cooperation, in terms of finance and experts, from the earlier stage of preparation to the initial stage of operation. Some donor countries strongly support these types of activities.

References

Abstract of International Symposium on Red Tides, Nov. 1987, Takamatu, Japan

Atkins Research Development (1979),A Monograph onAirPolution -Its Dispersion and Efsects, England.

Environment Agency (19SS), White Paperfor the Status of Environment in Japan, Japan.

Environment Agency (1988), The Environment of Seto Inland Sea, Japan.

Environment Agency (1985), Results of Water Quality Monitoring in Public Water Bodies in F4, 1987, Water Quality Burear, Japan.

Environment Science Dictionary, 1985 (Japanese), Tokyo.

Hungspreugs M., Heavy Metals and Other Non-oil Pollutants in Southeast Asia, AMBIO Vol. XVII, No. 1, 1988.

IRPTCI UNEP, International Register of Potentially Toxic Chemicals, 1985, Switzerland.

Onogawa K., Urban Environmental Problems in Asia and the Pacific, A fundamental element for the solution of problems, POLMET 88 HK, 1988.

UNEP, The State of Environment 1988, Environment and Health, Kenya.

UNEP/ ROAP, Selected Indicators of Food and Agricultural Development in Asia - Pacific Region. 1977437, Thailand.

UNEPI ROAP, Newsletter, January - March 1989, Thailand.

Chapter 8

Degradation of the Forest Ecosystem*

The Philippines has a total land area of 30 million hectares. About 70 per cent or around 27 million hectares are considered watersheds. Most of these areas were originally forested. These areas are the primary sources of valuable natural resources, foremost of which is the forest.

Through the years, the forest based industries have been contributing substantially to the country’s treasury. During the early seventies, the forestry sector ranked as the number one dollar earner for the country. To date, the forest-based industries still contribute substantial foreign earnings to the country. The wood sector export receipt amounted to US $264 million in 1988. It was US $246 million in 1987.

The monetary benefits derived from the forest based industries are not without premium, and a costly one at that. Because of the continued and uncontrolled felling of the forest trees without the corresponding replenishment of the same, degradation of not only the forest but also other natural resources is inevitable. Such continuing degradation of the country’s forests has brought about far reaching social, cultural and economic implications. This chapter en- deavours to present some insights/observations on the social, cultural and economic implications of forest degradation.

Social Implications

Forest degradation brings about a number of adverse social implications which include the following:

l Broken expectations and dislocated families;

l “Ghost” communities;

l Inequitable distribution of benefits from forest resources; and

l More impoverished workers and upland occupants.

Forest product harvesting (i.e., logging) and consequent wood processing activities supported once flourishing communities. These communities and the occupants were totally dependent on forestry activities and support systems. As long as the forests abound, these

* Prepared by Dr. Sever0 R. Saplaco, Associate Professor, UPLB College of Forestry and Project Director, ASEAN-US Watershed Project, Philippines.


communities and the needs and expectations of the people will continue to exist. However, as soon as the forests are gone, the people’s primary source of employment is lost. Inevitably, their expectations of gainful employment are unfulfilled and the forest dependent families in these communities will inevitably be dislocated.

It was not the expectation of the affected families to be deprived of a gainful employment. The forest resources appeared inexhaustible to them. However, slowly but surely, the forests continued to disappear. With the forest gone, there’s not enough choice left for the forest dependent families to earn a living but to force their way into the logged- over areas. As such, most if not all of the on-site forest dependent families become upland farmers. Unfortunately, they are not prepared to properly use the fragile uplands.

At best, they practice sloping upland cultivation that brought about the destructive “kaingin making” on upland areas. In short, they become dislocated, not only in terms of being unemployed but in being unprepared to appropriately face the challenge of upland farming - their new source of livelihood. Moreover, they become agents of further degradation not only of the forests but also other upland resources including soil, wildlife and others.

Many cases have been observed where once “flourishing forest dependent communities” became “ghost communities” when the logging activities ceased. The families have no other choice but to leave the community to look for other employment somewhere else. Inevitably, many families became dislocated when the forest related businesses ended.

The logging boom, particularly during the 19703, also brought about another adverse social implication via inequitable distribution of benefits derived from the forests. The forest workers were virtually “slaves” in the woods, working long hours, lowly paid and prone to all kinds of adverse field weather conditions and work hazards. On the other hand, the capitalists (concessionaires) and fly-by-night forest operators raked in millions of pesos’ worth of forest products cut from the public forests. It is safe to say that only a few, notably capitalists (small and big time loggers), benefited mostly from the rapid forest degradations. On the contrary, more workers, particularly the lowly paid labourers, became even more impoverished.

Since some of the dislocated workers have nowhere to go, they are forced to eke out a living through primitive upland cultivation or kaingin making. Because the upland areas are so fragile or erosion-prone, the more the occupants work on the land and practice sloping cultivation, the more the land becomes infertile because of excessive soil erosion. If the soil is eroded, crop production is significantly lowered until such time that the land can no longer support crop growth. A similar situation happens on kaingin areas. As this happens, the more the upland farmers work on the eroded and degraded lands, the more they become impoverished. Hence, there is a continuing degradation of not only the forest lands but also the entire spectrum of the upland resources, including man.

Cultural Implications

Forest degradation also impinges upon the cultural values/norms of the people, particularly the upland occupants/cultural minorities. For many generations, cultural minorities such as the upland dwellers in the northern mountain provinces (Igorots, etc.) the Balugas in the Zambales mountains, the “world famous” Tasadays and others, have held cultural values that are adversely affected by forest degradation. For example, it is a customary belief of cultural minorities that they have prior rights over their ancestral lands. They believe that they have all the rights/privileges in the use/disposition of the said ancestral lands, most, if not all, of which

Degradation of the Forest Ecosystem 113

are public forest lands. This cultural belief runs counter to reality with existing laws and regulations placing the jurisdiction, administration and management of forest lands under the government, particularly the Department of Environment and Natural Resources (DENR).

Most often, because of the conflict between reality and belief, the cultural minorities appear combative and less supportive, if at all, of the policies/programmes of the concerned agencies, in this case the DENR. Consequently, many forest development programmes fail due to non-cooperation of concerned parties.

In some cases, because of conflict in overall development strategies of alleged ancestral lands (public forests), worthwhile development projects are adversely affected or even aborted. The Chico Dam project is a case in point where cultural heritage of cultural minorities over ancestral lands delayed if not aborted the dam construction. This case even reached a point where lives were lost because the cultural minorities would not allow the inundation of their ancestral lands by the Chico Dam. They strongly protested the alleged encroachment over their cultural heritage by the development project. Likewise, other upland developmental projects, including forest degradation, seriously impinge upon the integrity and pristine conditions of their alleged ancestral lands. In short, forest and other resource degradation bring about adverse cultural implications, particularly among the cultural minorities.

Economic Implications

Forest degradation also brings about adverse economic effects. These effects include the following:

0 Unemployment;

l Export receipt diminution; and

l Environmental degradation.

At present, the wood-using industry directly employs about 200 000 people compared to about 93 694 in 1982. Another 400 000 people are indirectly employed in wood-related businesses.

The employment generation ability of the industry is sustainable as long as the forest base is properly protected and conserved. Ironically, even with the basic recognition of the importance of forest conservation and the presence of advanced forest management technologies, the country’s forests are continually being degraded. As a result, it is reported that only about 22 per cent of the total land area of the country is presently forested compared to about 57 per cent in the early 1950s. In short, about 10.5 million hectares of forest lands were lost or degraded within a period of about 40 years. This means that, on the average, about 262 000 hectares of forest lands have been lost/degraded every year for the last forty years.

Forest degradation is caused primarily by uncontrolled timber harvesting by loggers (legal and illegal), kaingineros, and other upland dwellers. To date, there are about 18 million upland dwellers, eight million of which are inside the forest lands. Most if not all of the eight million people practice “slash and burn” or kaingin farming inside the forest lands. Inescapably, they cause tremendous forest destruction.

When the country’s forests are gone, so is the wood-using industry. As a result, the large number of people presently employed by the wood-using industry will lose their jobs.


While there is substantial monetary benefits derived from the forest-based industries, such benefits will be forever lost when the country’s forests are destroyed. From 1970-1973, forest products were the country’s top dollar earners. The earnings in 1970 and 1973 were US $301.2 and US $444 million respectively.

Assuming that the wood using industry stops because there are no more forests, it is estimated that a minimum of US $300 million foreign exchange earnings will be lost per year. In addition, the country would need at least US $400 million for the importation of wood. Certainly, these are staggering amounts that would cause serious economic dislocations in the country.

Coupled with unemployment and serious economic dislocation, the country would experience serious environmental problems when the country’s forests are gone. Notable problems are accelerated soil erosion, siltation of multi-million peso hydro-electric/multi-purpose dams/canals, flooding and droughts. Soil erosion slowly but surely erodes soil fertility. As soil fertility is diminished, crop production will fail unless fertilizers are applied.

Accelerated soil erosion causes rapid siltation of expensive reservoirs resulting in the shortened service life of the structure. This leads to the disruption of delivery of vital support services such as electricity and water supply. Likewise, with the forest gone, flash flooding during the rainy season, caused by excessive surface runoff from the mountain watersheds is inevitable. The miseries and hardships that flooding brings to man cannot be overemphasized. In addition, water shortage would be expected during the summer months when the forests are destroyed. This happens because of the absence of the trees and other vegetation that regulate flood/surface runoff for continuous water supply even during the summer months. Again, without water, the adverse impacts to the country would be tremendous.

On the whole, forest degradation/destruction, while it brings temporal monetary benefits to a selected few, undoubtedly causes adverse social, cultural, economic as well as environmental implications.

Recognizing these problems, the ASEAN countries responded to help address the problems of continuing forest degradation in the region. It is through this concern that the ASEAN-US Watershed Project was started in 1986.

References

A SEAN- US Watershed Project Proceedings. 1984

Logging Ban. Will It Save Our Forests? PWPA. 1989.

Philippine Forestry Statistics. 1987.

Presidential Decree 705.

Chapter 9

Ecological Impacts on Aquatic Ecosystems*

A fundamental feature of the earth is the abundance of water. Water covers 71 per cent of the earth’s surface to an average depth of 1,158 metres. The quantity of water constituting the earth’s hydrosphere is immense - over 97 per cent of it deposited in ocean depressions and less than 3 per cent in freshwater lakes and rivers.

Marine and freshwater habitats support a diversity of life forms whose survival, growth, development and movement are consistent with the physical and chemical conditions of aquatic systems. Not only have aquatic organisms been moulded by these conditions through evolution, but conditions in the aquatic environment have been modified by these organisms to suit their life habits and activities.

Man’s concern for water and the biological communities in aquatic ecosystems is focused on the roles that these aquatic resources play in his environment and on his knowledge of these organisms in managing his environment to best satisfy his needs.

The value placed on aquatic resources to promote and sustain human development is of major concern in making policy decisions relating to their management. There is an urgent need to recognize the importance of reconciling the goals of achieving economic prosperity with the goals of maintaining environmental quality in developing aquatic resources to improve human life.

Multiple Use of Water Resources

Water has many uses. Although less than 50 per cent of the total freshwater resource on earth is potentially available for human use, the demand for freshwater is enormous. Of the 2.6 to 3.5 trillion cubic metres of freshwater reserve on earth, 73 per cent is devoted to crop irrigation, 21 per cent to industry, and the remaining 6 per cent is used for domestic and recreational needs such as drinking and washing. Human’s physiological requirement for freshwater amounts to 2 litres per head per day. Human settlements and commerce have often appeared where water was most accessible and plentiful.

The oceans of the world provide major sources of animal protein. The waterways have facilitated transport and communication. Coastal areas provide a convenient depository and disposal sites for tonnage of urban wastes and industrial effluents. The seabed is rich in mineral

* Prepared by Dr. Armando A. Andaya, Dept. of Biology, De La Salle University, Manila, Philippines.

-

Part I - The Know/edge Base 776

deposits and fossil fuel reserves. Hydro-power from dams and reservoirs constitutes a major source of electricity in modern times.

Environmental Impacts of Water Resource Use

Incompatibilities among the uses of water resources are becoming increasingly apparent as development activities increase. The rates of exploitation and consumption of aquatic resources are likely to increase with increasing pressures due to population growth and the demand for a better quality of life. It is anticipated that the rapid rate of exploitation of aquatic resources may lead ultimately to the degradation of water ecosystems and the deterioration of water quality.

In the Philippines, development projects which are declared “environmentally critical” are subjected to strict government regulation as stipulated in Proclamation No. 2146. An environmental impact assessment (EIA) is undertaken prior to the issuance of a permit to initiate and/or to operate an “environmentally critical” development project/programme. An EIA involves the identification and prediction of impact(s) of proposed projects and programmes on the biogeophysical environment and on man’s health and well-being, and the interpretation/communication of information about such impacts in a manner which can be utilized by planners and decision-makers. It is an important planning tool because it measures resource allocation and utilization in terms of the costs associated with environmental conservation.

The various types of development activities known to cause environmental impacts on aquatic ecosystems can be grouped into: Managed Ecosystems (agriculture and farming, forestry, ranching and feedlots, aquaculture and mariculture, nearshore catch fisheries); Con- struction and Transportation Facilities (dredge and fill activities, airfields, causeways and highways, harbours, shipping); Industrial and Related Developments (military facilities, electric power generation, heavy industry, offshore gas and oil development, coastal mining, upland mining); and Land and Resort Development (sanitary sewage discharges, solid waste disposal, water development and control, shoreline management and use, land clearing and site preparation, coastal resource uses).

In general, the environmental impacts associated with these development activities are related to the changes caused to the physical environment which in turn result in some ecological and socio-economic consequences. These physical changes include: 1. Temperature;2. Dissolved Oxygen; 3. Nutrients; 4. Salinity; 5. Hydrology/Oceanography; 6. Siltation/Sedimentation; 7. Water Purification/Toxic Substances; 8. Pathologic Substances; 9. Physical Disruption; 10. Soil Erosion; 11. Debris and Solid Wastes; 12. Change in Cover; 13. Overexploitation; 14. Disruption of Migration; 15. Disturbance of Behaviour; 16. Overload- ing/Encroachment.

It is evident that the environmental impacts of these development activities can have direct or indirect effects on species population or on communities of aquatic ecosystems. At the ecosystem level, the effects of these activities may be multiple and interactive. With some exceptions the general effects on the ecosystems can be summarized as follows: 1. Biological Displacement/Change in Species Composition; 2. Lowered Species Diversity; 3. Reduction of Standing Crop; 4. Reproduction/Recruitment Failure; 5. Overutilization of Selected Species; 6. Smothering of Sedentary Species; 7. Mass Kills; 8. Respiratory Stress; 9. Inhibition of Photosynthesis; 10. Food Chain Concentration; 11. Diseases of Stock; 12. Habitat Modifica- tion/Destruction.

Aquatic Ecosystems 117

The ecological consequences associated with the physical changes caused by development activities can lead to loss of economic opportunities. The socio-economic consequences of environmental impacts of development activities include: 1. Reduction in export earning potential; 2. Reduction in incomes for commercial fishermen; 3. Reduction in availability of protein source; 4. Increase in underemployment and unemployment in rural areas; 5. Increased incidence of human diseases.

Dam Construction - possible impacts

The construction of a dam in the upstream section of a river is envisioned to provide benefits to the people: power, water storage, flood control, fisheries, recreation and irrigation. The costs would be those of construction, operation and maintenance plus some attention to people resettled from the inundated area of the reservoir.

However, a multipurpose dam project creates an environmental situation which leads to the physical alteration of the river basin and causes numerous ecological and socio-economic consequences in the area. First, the displaced people may move in several directions: to steeper lands, to the now protected flood plain, or to the new lake shore. Since the upper watershed may already support human activity such as logging, tree crops, shifting agriculture and settlements, the addition of resettled lowlanders may mean shorter rotation periods, farming of marginal lands and penetration via logging access roads into steeper more erodable areas. An increase in soil erosion is virtually certain, and some of the resulting sediment will move downstream to the new lake, threatening to cause abrasion damage to hydro-electric turbine blades and turbidity (which may interfere with fish spawning). Accompanying nutrients may fertilize the growth of aquatic weeds with subsequent fish losses due to decreases in dissolved oxygen when the weeds die and decompose. Ultimately, the sediment displaces water in the reservoir, directly decreasing storage capacity and reducing the useful life of the electricity generating facility.

Irrigation water is delivered to intensified agriculture fields where, invariably, fertilizers and chemical pesticides are used. The runoff or irrigation return flow to the lower river basin may be substantially contaminated and thus affect fisheries and plant growth in the estuary and delta areas, resulting in loss of income to local communities.

Migratory fish may be prevented from moving upstream to spawn by the dam, thus threatening their population. Downstream fisheries may also be affected by a change in water temperature due to the impoundment. Additionally, alteration of fresh water delivery of nutrients and sediments to coastal mangrove forests is a major cause of their destruction.

A reduction in storage capacity of the reservoir means that less storm water can be intercepted by the dam. In periods of heavy rainfall the spillways must be opened, thus negating the promised flood protection which has attracted residents and investments to the now vulnerable flood plain. In total, the entire watershed and its people will have become dependent on a water management system that is shortlived and which no longer brings the expected benefits.

The multipurpose dam can bring about changes in hydrological patterns, soil erosion, siltation, and flooding in these areas, resulting in losses in forestry, agricultural land and fisheries, reduction in the useful life of downstream hydropower facilities, loss of property, and increased incidence of disease.

---


References

ADB. 1986. Economic Analysis of the Environmental Impacts of Development Projecfi. Manila. The Asian Development Bank.

Carpenter, R.A. 1983. Natural Systems for Development: What the Planner Needs to Know. New York. MacMillan Publ. Co.

Connell, D.W. and G.J. Miller. 1984. Chemistry and Ecotoxicology of Pollution. New York. John Wiley & Sons.

IDRC. 1989. Searching Freshwater: The Human Imperative. Ottawa. International Develop- ment and Research Centre.

NEPC. 1983. Environmental ImpactAssessment Handbook Manila. Ministry of Human Settle- ment, National Environmental Protection Council.

Royston, M.G. 1979. Pollution Prevention Pays. Oxford. Pergamon Press.

Unesco. 1981. Environmental Education in Asia and the Pacific- Bangkok. Bulletin of the Unesco Regional Office for Education in Asia and the Pacific.

Westman, W.E. 1985. Ecology, Impact Assessment, and Environmenta! Planning. New York. John Wiley & Sons.

Chapter 10

The Effects of Energy and Mineral Extraction*

Minerals play a vital role in the economy of most countries. A large number of minerals are tradeable in the world market, providing a country with the means to secure from abroad the goods and services it needs for social and economic development or for survival. Some developing countries depend on minerals as their principal source of foreign exchange or even as the main basis of their economies. As a country industrializes its demand for minerals intensifies for reasons different from those that obtained before industrialization.

ASEAN is a region richly endowed with mineral wealth. It is one of the top producers of tin, petroleum, copper, nickel, gold and chromite. It is also endowed with other minerals like coal, aluminium and iron. Table 10.1 shows the importance of the mineral industries to countries in ASEAN as indicated by their share in GDP or gross domestic product. Notice the high percentage, 26 per cent, contribution of minerals to the GDP of Indonesia, a mineral-rich developing country, and the 13 per cent contribution to GDP of Singapore, a mineral-poor, newly industrialized country. Table 10.2 is another indicator of the role of minerals in the economies of the ASEAN countries. Note the very high proportion of minerals in the exports of Indonesia as well as Singapore, suggesting that minerals play an important role in the economy of a mineral-rich developing country as well as in the economy of a newly industrialized but mineral-poor country. Table 10.3 identifies the most important mineral exports, with petroleum and petroleum products, tin and copper being the most dominant. Table 10.4 identifies the major minerals that enter into the import accounts of the ASEAN countries, led by petroleum and petroleum products, steel products and fertilizer.

While the benefits from mineral resource extraction and use are well known, certain sectors of society point to the adverse effects of mineral production and use on the environment. Certain sectors allege, for instance, that mine pollution has caused the siltation of rivers, irrigation systems and farms to the extent that fishes have disappeared and farm production has been drastically reduced. Some further claim that mine pits destroy the beauty of the landscape and liquid, dissolved and solid wastes pollute the air or the water resources. Consequently, some laws have been passed which have either banned or restricted mining operations ofcertain types or in certain places with serious social and economic repercussions.

* Prepared by Dr. Teodoro M. Santos, Professor of Geology and Mineral Economic3 at the National Institute of Geological Sciences, College of Science, University of the Philippines, Diliman, Quezon City.


Table 10.1. Relative importance of minerals sectors, 1980

Indonesia

Malaysia l------ Philippines

Value of Output (US$ million)

17000

1170

1660

Share of GDP (percent)

26.0

4.6

4.7

2.1

1200 13.0

7500 5.2

Source: Mckern & Koomsup, 1988. The Minerals Industries of ASEAN..., p. 1.

Table 10.2. Percentage share of minerals in trade

Source: Mckern, & Koomsup, 1988. The Minerals Industries of ASEAN..., p. 2.

Note: a. 1970

Effects of Energy and Mineral Extraction 121

Table I (I..?. Pkcipal exports of minerals and mineral products, 1981

Mineral Percentage of Total I Mineral exports

Indonesia

L Petroleum 77

LNG 18

Tin 2 Nonferrous ores 2

Malaysia Petroleum 73

/--z&r Tin 22 Nonferrous ores, including copper 55

I nickel 11 Singapore

I---- Petroleum products 72

Petrochemicals 12

Tin 3 Thailand Tin 63

Nonferrous ores 8 Precious metals, gems 6 Coal 25

Iron ore, Iron and steel 19

Alumina, aluminium 16

Lead 8

Nickel 6

LPG 5

Zinc 4

Copper 4

Source: Mckern, Cyr Koomsup. 1988. The Minerals Industries of ASEAN..., p. 3.


Table 10.4. Principal imports of minerals and mineral products, 1981

Indonesia

Malaysia

Philippines

Singapore

Thailand

Mineral

Petroleum, crude

Petroleum products

Steel products

Fertiliser (manufactured)

Petroleum, crude

Petroleum products Nonferrous ores


Steel products

Petroleum, crude

Petroleum products

Steel products


Petroleum, crude

Petroleum products

Steel products Petroleum, crude

Petroleum products

Steel products

Percentage of Total Minerals Imports,

All Sources

17

26

33

7

25

30 4

4

19

65

11 12

4

71

9

Source: Mckern, & Koomsup. 1988. The Minerals Industries of ASEAN..., p. 7.

This chapter therefore aims to present both the major benefits and drawbacks of mineral extraction and use. Specifically, it briefly focuses on the role of minerals in the economy and on their adverse impacts on the environment. It also presents some analytical tools which may be used to assess the proper balance between mineral production and use on the one hand and environmental protection on the other. The paper likewise aims to highlight a method of instruction whereby the trainees (students) deduce their own conclusions from given data or facts using pertinent analytical models or approaches.

As far as terminologies are concerned note that: “environment” as used here includes the natural physical and biological factors which surround a particular mining operation, including


man and his creations; “minerals” when used in the general sense embraces energy, metallic and non-metallic minerals; when used alongside energy or energy minerals, it refers to hard minerals or metallic and non-metallic minerals.

The Role of Minerals in Economic and Social Development

The significance of minerals in a country’s economy changes in accordance with the stage of economic development it is in, given its mineral endowment. One role declines or obsolesces as another even more important role becomes pre-eminent.

Mineral Consumption an Indicator of Wealth Level

It is generally believed that the level of wealth or income correlates with the level of mineral consumption. That is, the greater the per capita mineral consumption the greater is the per capita income. This may be so because increasing per capita mineral consumption reflects increasing industrialization which, in turn, is usually associated with increasing wealth. (See Table 10.5 and Table 10.6.)

Though increasing per capita income generally increases with per capita mineral consumption, a certain maximum level of per capita mineralconsumption exists for a given society beyond which any further increase in per capita income is attended by decreasing per capita consumption. This behaviour gives rise to an inverted U-shaped curve, corresponding to the Intensity of Use Hypothesis propounded by Malenbaum (Campbell, 1985). Such behaviour is interpreted as follows: in the early stage of a country’s development per capita consumption of minerals is generally low; however, as the society drives towards industrialization or development its per capita consumption of minerals increases rapidly, first to lay down the infrastructures necessary for take off, then to feed the growth of its secondary or manufacturing industries. After the essential infrastructures have been built and the secondary or manufacturing industries developed, further increases in income are realized by developing the service sector which is generally considered not to be mineral intensive, hence the decline in the mineral consumption.

Contribution to the Economy

The contribution of the mineral industry to the development of its host economy can be better appreciated by looking at certain indicators in the context of developing/developed economies.

Since a developing country is characterized, among other things, by scarce capital, poorly developed infrastructure, low income, underdeveloped labour force, uncompetitive secondary industry and a dominant subsistence agricultural economy, one can envision that any activity which enhances a country’s position with respect to the preceding items also promotes its social and economic development. In this context a large mineral project enhances development of the host community. Table 10.7 summarizes the characteristics of a developing economy from which we can also infer the characteristics of a developed economy.

Briefly, a mineral project contributes to its host community (country) as outlined in the following (McDivitt & Jeffereys. 1976).


Table 10.5. Relation of per capita energy and steel consumption to income

Australia

Belgium

Canada Japan

Sweden

USA India

Energy Consumption, Kg per Capita

in Coal Equivalent 1968 5124

5236

8483

2515

5360

10311

184

Steel Comsumption, Kg per Capita,

1968 489

409

489 494

623

685 11

Per Capita GDP 1968

2042*

1882

2621

1306

2905

3960 77*

Source: Toombs & Andrews. 1976,3rd ed., Economics of the Mineral Industries, p. 35

Note: * = 1967 Statistics.

Effects of Energy and Mineral Extracfion 125

Table 10.6. Energy1 GDP ratios for the Asia - Paci..!. region

Energy comsumption Energy/ GDP Current GNP per capita Country per capita (kce) a (per capita in kce per US$) (UW

1965 1972 1978 1%5 1972 1978 1966 1972 1978

SOUTH AND WEST ASIA

Afghanistan 30 37 NA 0.264 0.309 NA NA NA NA

Bangladesh NA 32b 43 NA 0.260b 0.284 70 70 loo

India 174 193 17ge 1.415 1.403 1.180 90 110 180

Nepal 9 15 He 0.075 0.127 0.089 80 80 120

Pakistan 82 117 172 NA 1.163 1.024 120 160 220

Sri Lanka 118 138 109 0.623 0.614 0.364 170 160 220

Iran 395 993 1542 0.528 0.714 0.926 NA NA NA

SOUTH EAST ASIA

Burma 49 61 6oe 0.412 0.504 0.461 60 80 150

Indonesia 112 128 278 0.758 0.665 1.076 40 loo 380

Malaysia 357 686 738 0.676 0.990 0.792 340 450 1140

Philippines 218 287 339 0.763 0.874 0.830 200 220 520

Singapore 749 1466 2461 0.723 0.690 0.807 590 1270 3310

Thailand 130 264 327 0.588 0.873 0.082 150 200 500

Cambodia 46 24 NA 0.053 0.035 NA NA NA NA

Laos 35 82 NA 0.521 0.990 NA NA NA NA

South Vietnam 149 425 NA 0.997 3.050 NA NA NA NA

EAST ASIA (LDCS)

China 456 572 837 1.856 1.734 1.889 110 130 210

South Korea 435 796 1359 1.605 1.764 1.754 130 210 1190

PACIFIC ISLANDS (LDCS)

Fiji 365’ 491 466 0.567’ 0.578 0.373 310 510 1350

Papua New 85d 253 293e 0.231 0.565 0.623 170 310 650 Guinea

INDUSTRIALIZED COUNTRIES

Australia 4659 5640 6622 0.971 0.946 1.007 2250 3690 8620

Canada 7074 %12 9930 1.459 1.513 1.272 2870 4810 9340

Japan 1817 3557 3825 0.738 0.784 0.780 1040 2540 7020

New Zealand 2437 3178 3555 0.63 1 0.740 0.777 2200 2850 4860

United States 9176 11617 . 11374 1.529 1.619 1.430 3930 5810 10110

Source: Fesharaki, F., et al., 1982. Critical Energy Issues in Asia and the Pacific. p. 70-71; TheWorld Bank, World Tables 1987. The fourth Edition. Washington, DC: The World Bank 1987.

Note: a. kce = kilograms of coal equivalent; b. 1973 data; c. 1968 data; d. 1968 data; e. 1977 data; NA = data not available


Financial Contributions

Some of the financial contributions of a mineral project to its host economy are:

Foreign Exchange. A developing country needs foreign exchange to secure from other countries the capital goods, technology and services that it needs in order to develop its economy. Since agriculture is generally subsistence and the manufacturing sector can not produce goods that can compete in the world market, minerals are the only goods which a developing country can use in trading with other countries, being demanded by industrialized countries and not yet needed by local industries.

Capital and Industry. A mineral project certainly adds to the stock of productive capital of the country. In fact it adds also to the country’s industries.

Income and Employment. Production from the mine enlarges national income as shown in Table 10.1. Ofcourse a mineral project also provides employment and hence income to local population.

Purchases from local industries. Such purchases stimulate economic activities in the host community which give rise to satellite industries, thereby enhancing economic and social development.

Government Revenues. A mineral project also contributes to the government coffers in the form of taxes, royalties and other charges or even profits where a national corporaton is involved in mineral extraction. Such revenues are used to provide basic services, and infrastructures.

Infrastructure

Since most mineral deposits occur in the undeveloped rural areas where infrastructures such as roads, bridges, hospitals and schools are virtually non-existent, the opening of a mineral project in such an area would cause these infrastructures to be built. In effect they will help stimulate growth and development in communities surrounding the mine as a result of, among others, access to outside markets and other facilities that can help improve health, education and communication.

Environment Conducive To Development

Since a large mining project, to be competitive, has to make use of the most efficient, scientific methods of production and management, it serves as a model of the operation of a modern, developed society. Daily contacts of employees and other people in the community give them training and experience in the ways of life in a developed society. In addition, to provide for its own needs for skilled labour, the mining firm conducts training, formal or informal, to train people in the local community as mechanics, electricians, drivers of different types of heavy and light equipment, and construction workers; it also provides training in management. These skills, especially when some of the trained personnel transfer to other firms, contribute substantially to the development of the host community or country.

The various contributions of the mining industry to the host community must be reflected in improved conditions for the people and the community such as government revenues, health, and education. A study made by Santos, Abiad and Delos Angeles (1982) of four mining towns and four non-mining towns in their vicinity indicates that the mining companies have indeed improved the social and economic well-being of their host communities.


Table 10.7. Diff erences between less developed and developed societies

Basis

Industry

Trade

Social Overhead Capital

Less developed society Developed society

Mainly agricultural Industrial

Little or no external trade Trade volume is substantial

Little infrastructure Well - developed infrastructure

Social Structure Rigid; traditional Flexible

Labor In great surplus but limited in skills and in concepts of entrepreneurship.

May or may not be scarce but has a range of skills to cope effectively with any intricacies of the production process

Capital Limited, slow in forming due to inability to accumulate savings and lack of tradition in investments.

Exist in adequate amounts and available for any good potential investment.

Land Worked by primitive methods; Produce agricultural, forest and offer marginal living and mineral products in amounts contributing little in the way of that are adequate relative to surplus which may serve as a population and work force; well springboard for development. endowed with water. Well Poorly developed transportation endowed with transportation and utilities sectors. and utilities.

Source: T.M. Santos, et al., 1982. The Role of Mining in National Development, p. 3.

Contribution of Minerals to Developed Economies

In the early stage of the development of a mineral-rich country, minerals are exported in the form of crude products such as direct shipping ores, concentrates, mattes or even refined metals. As the economy develops some of the crude mineral products are transformed into manufactured goods, thereby contributing to the outputs of the secondary industries. The use of minerals in the secondary industries enhances their role in the development of the tertiary or service industries. In developed countries like the US and Canada, intricate networks of roads, railroads, pipelines, ports, shipping, banks and insurance developed around such bulk mineral industries like the iron ore, coal, petroleum and natural gas industries.

Apart from their purely economic role, minerals are also important for the security of developed countries. This is so because minerals are indispensable inputs to the defense industry.


Table 10.8 shows the importance of minerals in the economy of industrialized countries as input into their secondary industries. Note that only a few industrialized countries account for the bulk of world mineral consumption.

Table 10.8. Metals consumption by industrial economies as a proportion of world consumption

Japan 1.2 7.0 1.5 11.0 1.5 5.2 2.6 11.2 2.6 9.3 0.7 11.3

Canada 3.7 2.6 4.0 4.3 2.8 1.7 2.5 2.4 2.6 2.2 2.0 2.3

Australia 0.5 1.2 1.4 1.4 2.7 2.1 2.6 2.4 1.9 2.2 0.7 0.6

TOTAL 82,s 74.7 82.5 76.2 83.0 67.7 83.1 72.0 80.2 66.6 79.3 72.8

Source: Toombs & Andrews, 1976. Economics of the Mineral Industries, 3rd ed., p. 42

Effects of Mining on the Physical Environment

Mining operations affect the land, water and air where they are located. Such effects are conditioned by many factors such as the type of mineral deposit, location with respect to the surface and the population centre, the technology used, particularly if open pit or underground, scale of operation, and climate. However, we focus only on the aggregate effects on the land, water and air environment.

Given the mineral deposit and the technologies employed, the environmental effects vary with respect to the stages of mineral production. For instance, in open pit copper mining, the environmental effects during the mining stage, which consists mainly in exposing and moving great volumes of rock and soil, differ from those during the smelting and refining stages which entail the liberation of noxious gases, such as sulphur dioxide and carbon monoxide, into the atmosphere,

A good idea of where, how, and why environment‘al impacts are effected by mining can be gained from a careful analysis of Fig. 10.1 which portray the elements and processes involved in the various stages of open cast coal mining and transporting. Note that open cast mining is the technology that imposes the severest environmental impacts among the various methods of mining, whether it relates to coal, copper, gold or any other mineral. The succession of natural vegetation, access road, prestrip area, strip or overburden area, area of active mining operations, waste dumps, rehabilitation area and area of various mining facilities which represent different types and degrees of environmental degradation.

The following presentation aims mainly to state ‘and illustrate the impacts of mineral extraction and use on the physical (and to some extent biological) environment. The treatment is definitely not exhaustive. The main references used are Aisong (1987), Miller (1985) and Fesharaki et. al. (1987).

. .

Overburden

Coal Seam

Clean coal Stockpile

Washplant Rejects

Bin

Raw Coal Stockpile

Shiploader

Unit Coal Train

Figure 10.1. Diagram showing the complete opencast mining cycle ( Mining Magazine, Nov. 1988)


Effects on Land and Soil

Fig. 10.2 (Fesharaki, et al., 1987) which graphically summarizes the adverse environmental impacts of coal on air, land and water serves as an excellent introduction to the physical environmental impacts of mining. Extraction of other minerals such as copper, iron ore, gold and diamonds, among others, entail similar effects. Mining operations affect the land forms (geomorphology) and the soil both directly and indirectly. Some of the more prominent effects are:

Effect on the top soil. The top soil that supports plant life and which required millions of years to form may be removed in the course of preparing the mine pits and during the construction of roads, buildings and other physical facilities. Moreover, it is also exposed to rapid erosion when the vegetative cover is removed. Areas so affected are therefore ill suited for growing crops and trees, rendering them unproductive at least in the agricultural sense. (To mitigate this impact the top soil is usually stockpiled in a separate place for reuse in reclaiming mined out areas later.)

Destruction of Large Areas of Land by Opencast Mining. The extraction of ores suitable to open pit mining subjects large areas to massive excavation and removal of large volumes of rock and soil materials. This results in the formation of huge pits where hills were located before and which are considered by some to destroy the beauty of the landscape not to mention the fact that they may form hazards to men and animals long after the mine is abandoned. Iron ore, low grade copper, low grade gold, coal, diamonds, shale oil and tar sands, among others, have been the object of this type of mining. To give us an idea of the magnitude of the area affected by open pit operations it is reported that in China alone about 133 400000 sqm of land are affected annually, by mining operations carried out by the departments of metallurgy, coal industry, non-ferrous metal extraction, building material and chemical industry.

Accumulation of Waste Rocks and Tailings. This occupies land which otherwise could have been used for purposes such as agriculture and forestry. It also spoils the aesthetic value of the landscape. Finally, such piles of rocks and tailings are also a fertile source of dusts, which pollute the air, and of silt and sand which may fill stream beds or even bury irrigation channels and farmlands.

Land Subsidence. Subsidence may be associated with underground mining and with the withdrawal of fluids from the ground. This may be observed in areas where extensive withdrawal of petroleum, natural gas or water occurs. The sizes of the collapses are in the order of l-5m across and in depth, but have reached as large as 40m across and 30 m deep occasionally. The greatest collapse reported in China involved the displacement of 4 600 cubic metres in an area of about 500 hectares.

Occurrence of Avalanches, Landslides and Mudflows. Weakening of the rocks due to mining activities, accumulation of silt sand, and other debris in mine dams or in natural depressions may give rise to avalanches, landslides or mudflows which on occasion may lead to great loss of life and property.

Polycyclic oraanio mataiala

Polycyollc Traos dsmentn Radlonuollden or~ado mntmiala

Polycyclic t / orqanio matariala I /- co,

Am I co Sulfur I

co !3ulfur PEXtiol~ oompollnda

----!/--- Particlea

\t/---- compoundn

_._ Fumes from fires Fumea from fhm

t surfaca

mhls Top =dl Mine WaDto

l-l 00 -AAsaa .v

Coal dust Acid n3.h

SlUdgS

1 water COMUDjIUOJl --- _- - _._----

IF-

._.--. - ---._ .--- .-.-- -- -------- Laldlates- --h water coIlmunpUall---.

-__--_------ -- --. ---- __--__---

~WATER- --- Add mhs dratnegs - Diawl~cd and ---- Thermal dlschmw - Sedlmenhtion ;-- Suspended rnol.ls~~~ZI~

-- p&IIdm, ollutanir ~zz~~:.~.~:_~~ Lln ---

--- - la - **:- ---_- -__ _.-.-_ -- . ..___I ----- -- _---~ _..-__ __.__-._____ _ ____ -- -__-. - .-.. - - _ --.---.- -__-

Figure 10.2. Environmental disturbances from coal-related activities.


Effects on Water Resources

Mining operations affect water resources in a variety of ways. The effect may be spatial, quantitative or qualitative. We illustrate below some of the effects of mining on water resources.

Effects on Sueace and Underground Waters. Intensive drainage, particularly of water saturated ore deposits, may cause the drying of some streams or of the regional groundwater discharge in springs or outlets of underground rivers. Such effects are usually associated with subsidences. For example, about 372 000 tons per day of mine waters are disposed of by mining firms in the Philippines (Sebua, 1989). However, there is no statement on whether such waters are polluted or not.

Effects on the Quality of Water. Many mineral deposits commonly contain pyrites and other sulphur bearing minerals. When acted upon by water such minerals decompose and produce acid water. Again, the exposure of the same minerals in tailings and piles of waste rocks facilitates the formation of acid waters. Heavy metals may also be leached from the exposed ores, tailings and waste rocks, such as Fe, Cu, Hg, Pb, As, Sb, Cd and others, which may increase their concentrations above tolerable levels in surface or groundwaters. A mine producing mercury in Palawan was shut down for causing mercury pollution in the surrounding waters. But a bigger threat of mercury pollution on a national level is posed by the official encouragement of small scale mining throughout the country (as for instance embodied in the Proposed Peoples’ Mining act of 1988). Small scale gold mining operations have been blamed for mercury pollution in the rivers, lakes and seas in Mindanao, particularly Davao and Surigao, and probably in Pangasinan and other areas. Waters associated with hot rocks, such as those obtaining in geothermal systems, are effective solvents of metals and other elements. Consequently, when they are drawn from their sources and then discharged to such bodies of water as rivers, creeks or seas, the dissolved materials become pollutants. Though the initialconcentrations may not be highenough to adversely affect health environmental agents such as planktons and other organisms, the environment might be able to concentrate them to toxic levels through a series of recycling by way of the food chain.

Heat. In deposits associated with hot waters which are drawn to the surface as in geothermal waters, or in processes which produce hot waters as a by-product, heat pollution results when such wastes are allowed to discharge into the surrounding bodies of water without,initial cooling.

Siltation. Mine tailings or silts washed from piles of rock wastes have been reported affecting some bodies of water. For instance, tailings from a local copper mine have been reported as causing the filling of a certain bay. In addition, the tailings from a group of mines have been blamed for the siltation and consequent death of some corals adversely affecting the fish catch of local fishermen. It is reported that a copper mine in Marinduque dumps 15 700 tons/day of tailings into Calancan Bay, and another mining company in Cebu dumps 15 000 tons/day into the sea. In all, mining companies in the Philippines dispose of 190 900 tons/day of tailings, much of which end up in the sea (Sebua, 1989). In the US in 1975,686 million tons of mine wastes were generated by copper mining, and another 500 million tons by iron and steel mining (Gulley & Macy, 1985).

Radioactivity. In mining radioactive minerals like uranium direct radiation, which may be harmful to health, is emitted. The radioactive minerals may also find theirwayinto groundwaters and other media and ultimately into humans’or animals’ bodies through the biotic chain, giving rise to radioactive diseases. There is a possibility that accidents could occur in the operation of uranium fired power plants, releasing significant amounts of radioactive materials into the


atmosphere and nearby water bodies, thereby contaminating a large area as happened in the case of the Chernobyl (U.S.S.R.) and Ten Mile Island (U.S.A.) nuclear facilities. Finally, disposal of wastes from nuclear plants has been a big environmental problem because of their long term toxic effects.

Others. There are other environmental effects of mining on water resources which occur rather irregularly but entail tremendous large scale impact when they do so.

One such effect comes in the form of oil spills. The most recent spill occurred in Prince William Sound in Alaska where the tanker Exxon Valdez, carrying more than 11 million gallons of oil, was wrecked when it rammed some rock bodies. Environmentalists, supported by newspapermen and politicians, complained loudly about the adverse effects on beaches and rocks spoiled by oil stains, and on sea otters and sea lions, seals, wild ducks and other wild life. It was also mentioned that the rich salmon and herring fishing grounds have been endangered as the oil slick threatened to pollute the coves and bays where the fishes spawn. (Newsweek, 1989; Time, 1989).

To savour the flavour of the environmental drama, one month after the oil spill about 1,800 sq miles of sea surface were affected by the oil slick, and 460 sea vessels, 26 aircraft and about 3 000 men were mobilized to fight the oil spill. The toll on Alaskan wildlife consists of 458 fallen sea otters, and 2 889 birds. More animal deaths have been suspected though not yet documented. Though human efforts to contain the oil spill after one month seem unimpressive, four days of rain and snow storm did a lot to clean the polluted beaches.

Other big oil spills of comparable impacts are the Torrey Canyon off the coast of England in 1967 and the Amoco Cadiz off Brittany in 1978. Experience in these previous oil spills indicates that, despite the grim prediction about the impact on wildlife in the Prince William Sound in Alaska, it is likely to rebound in two to three years.

Less dramatic oil spills occur in the Philippines. In 19761978,220 oil spills were recorded. Some of the notable spills range from 550 gallons to 22 300 barrels of oil. (Sebua, 1989).

Another type of pollution which has far reaching effects is acid rain which results from the interaction between sulphur dioxide emissions from smelters fed with sulphides of copper, lead, zinc and other metals and rainwater. This type of pollution has been responsible for the destruction of some crops and forests and the transformation of lakes into a form less suitable for fisheries and other uses.

Effects on the Atmosphere

Pollution of the air occurs during mining, beneliciating, smelting and refining or in the process of producing electricity. Pollution takes the form of dust or total suspended particulates (TSP), carbon monoxide (CO), sulphur dioxide (SO2), nitrogen oxides (NOx) and hydrocarbons (HC). Note that carbon dioxide is not normally considered a pollutant though associated with polluting gaseous emissions.

During blasting and drilling dusts and gaseous emissions, such as sulphur dioxide, carbon monoxide and nitrous oxide, are produced. Even more dusts are produced during the crushing and grinding of ores.

In the process of smelting sulphide ores in particular, large volumes of sulphur dioxide and carbon monoxide are produced, potentially causing not only severe air pollution but water


pollution as well. Similar effects are produced by the burning of sulphur bearing coal and other hydrocarbons in the process of producing electricity.

Table 10.9 illustrates some of the environmental impacts of the various stages of energy mineral extraction and utilization. Table 10.10 gives quantitative measures of the magnitude of the annual emissions from a coal-fired power plant. Care however, must be exercised in interpreting these data.

Table 10.9. Some Environmental impacts of energy conversion

Health Social Quality of life Property Environmental SeIViCeS

Exploration

Oil/ Gas Accidents Invasion of wilderness

Production

Coal mining Accidents, black lung

Accidents Dam collapse

Loss of farmland, subsidence

Loss of farmland

use of aboriginal lands

Defaced landscape

Acid drainage

Offshore oil Hydroelectric dam

Oil on beaches Loss of wild rivers

Oil as a blocide

Fish passage, wildlife breeding grounds

Displacement of residents

Processing Oil refining Smells, visibility

Waste piles

Air/ disease

Air/ disease

Population of estuaries

Water pollution

Air/ crops

Water consumotion

Air/ crops, buildings

Shale processing I I

Conversion

Coal power plant

Air/ disease Noise, visibility Acid rain, CO2 particles/ climate

jact Fission reactor Transportation

Oil tanker Electrical transmission

Plutonium

Reactor acciden It tt lat breached con tai nment would nr(

Fire Electrocution

Leak/ cancer

Fire, collision Restriction on land use Land contamination/ auarantine

Terrorism nuclear bombs

Air/ crops

Land use

&ll 132 all classes of i

Oil on beaches Unsightly towers

Suburbanization I Noise, visibility

nlJ

Oil as biocide

Consumption

Automobile Air/ disease Paved environment, heat/ climate

Waste

management

Radioactive wastes

Leak/ mutations Terrorism, sabotage

Groundwater contamination

Source: Fesharak, F., et al., 1987. Critical Energy Issues in Asia and the Pacific. p. 230.


Table 10.10. Annual emissions from a 900~MWcoal-fuedpowerplanta

Airborne effluents

Particulates

Sulfur oxidesb

Nitrogen oxides

Carbon monoxide

Hydrocarbons

Liquid eflluents

Organic material

Sulfuric acid

Chloride

Phosphate

Boron

Suspended solids

Solid waste

1.8 x 103

6.4 x 103

1.6 x 104

1.2 x lo3

230

38

48

15

24

190

290

Bottom and fly ash 2.1 x lo5

Source: Siddiqi, T. Environmental Aspects of Energy Development in Fesharaki, 1982, p. 238

Note: a. 1.75 mtcel year of coal with 2% sulfur, 12% ash, and 99% capture of fly ash.; b. Flue-gas desulfurization could potentially reduce sulfur oxide emissions by a factor of 10 to 20 some increase in solid and liquid wastes.

Impact Mitigation

Mitigation of the adverse impacts on land and soil must be part of the mine development plan. It consists of, among others, the conservation of the soil and the reclamation of affected areas. Reclamation includes the preservation of the topsoil, soil erosion control, topographic reconstruction and revegetation.

Adverse impacts on water resources are mitigated by recycling water, limiting the volume of water discharge from various phases of operations, by neutralizing acid waters, and by

~~_ .._ ..-_ . -------


impoundment. Construction of tailing ponds or dams reduce the siltation effect of mining on water bodies.

Dust and gas suppression techniques and collection systems are used to reduce particulate emissions. Suppression techniques are applied to hinder the generation of fugitive or process dust. As a rule the suppression of fugitive dust is done with the use of water. Where water does not setve the purpose well chemical stabilizers are used. To control emissions from smelters and power plants various devices are used such as mechanical collectors, precipitators, fabric filters. and scrubbers.

Analytical Methods

This section aims to introduce on the elementary level some bases for evaluating projects or environmental regulations. Specifically, it aims to:

. Provide a framework for thinking about costs and benefits;

l Measure costs and benefits;

l Illustrate the evaluation of alternate regulatory forms for attaining desirable levels of environmental quality.

Focus is mainly on economic efficiency and well-being. For simplicity, equity is not directly treated though it is no less important. Finally, some of the important limitations of the concepts are not discussed, though they are abundantly available in the references (Gulley, 1985; Guiley and Macy, 1985).

Principle of Cost-Benefit Analysis

Compensation Principle or the Kaldor-Hicks Criterion: Improvement in economic welfare is said to obtain if the movement from state A to state B makes everybody better off (or no one worse off). In this case state B is preferable to state A since under the former improvement in economic welfare can be achieved. Alternatively, improvement in welfare can also be attained if gainers will be able to fully compensate the losers while extra benefits still remain. That is, the change from state B to state A increases society’s welfare if the benefits exceed the costs.

Benefits may be measured in terms of “consumer and producer surplus”. Producer surplus may be thought of as profit, rent or quasi-rent. Consumer surplus, on the other hand, is that amount which a consumer is willing to pay in order to secure a particular amount of goods or services at some given price.

Compensating and Equivalent Variation. These criteria for measuring benefits and costs are based on the consumer’s willingness to pay. Compensating variation is the money transfer necessary after an economic change, such as the occurrence of an increase in air pollution, to restore the individual’s original welfare. Equivalent Variation is the amount of money which, in the absence of a contemplated change, affords the individual an exactly equivalent change in welfare (Mishan, 1971, p. 127).


Some Techniques of Measuring Benefits and Costs

Benefits and costs refer, among other things, to health, longevity, recreation, productivity and amenity. There are two common methods of measuring benefits or costs: the market and the survey approach.

Market Approach - Under this scheme benefits (costs) are inferred from some related markets. For instance, a reduction in acid rain increases crop harvests while a reduction in the sulphur dioxide emission of power plants leads to reduction in acid rain. Another example is where the price of two houses identical in every way except the view can be used to determine the value of the view.

Survey Approach - This approach may be based on opinion sampling, questionnaires, bidding or voting. For instance, people may be asked how much they are willing to pay for a particular improvement, say the construction of a bridge across a river or the reduction of air pollution from the present to some desirable level. People may also be asked how frequently they will visit a given park or museum if there is a charge of, say, one hundred pesos per head per visit. Or people may be allowed to vote from among a given set of alternatives.

Evaluating Benefits and Costs - Benefits and costs must be referred to a specified state, such as the present polluted state of Metro Manila or some pristine state. If reduced pollution is a desired change in state, then the benefits are the favourable results of reduced pollution. Damages must be the undesirable results of pollution, hence a reduction in such damages must be counted as a benefit. The term cost must be restricted to the sacrifices associated with compliance; it must not include, for instance, damages forgone as a result of compliance or damage remaining after compliance.

Categories of Costs (Benefits) - These may be direct or indirect. Direct costs include the costs of the regulatory agency as well as expenditures of the private sector. For instance, costs include the capital and operating costs associated with compliance such as the cost of the stack gas scrubber and its installation and operation, should the regulatory agency require a power plant to install a scrubber. Indirect or unintended costs include, for instance, the cost of excess capacity if idling of older facilities is resorted to in order to comply; productivity losses; or the adverse effect on competition. Effects on prices and employment are also included under indirect costs (benefits).

Economics Approach to Environmental Regulation

From the economics perspective environmental pollution (and even indirect benefits from mining operations) arise because they are not “internalized” in the operations of the firm, that is they are not included consciously in the costs or revenues of the firm. In this sense it is called an “externality” because its cost (or benefit) is external to the firm. This point of view is important in understanding the application of economic principles to environmental control or regulation.

Two general schemes of environmental regulation currently in use are:

a. The command control system under which the government dictates the desired behaviour, such as what technology to use in pollution abatement and what level of abatement is needed;

b. The decentralized scheme under which the government alters some elements of the market by such schemes as imposing taxes on undesirable performance or giving

Part / - The Knowledge Base 138

incentives to desirable performance, then leaving to individual decision makers the manner by which to attain the desirable behaviour.

Under ideal conditions (perfect information on benefits and costs, and low transaction cost, i.e. the cost of identifying all parties and making them agree), an optimum level of pollution abatement can be found by allocating private property rights to individuals. Under this scheme, the government does not need to do any other thing to attain optimum abatement except to provide the courts that will enforce the law on property rights. The same optimal solution can be arrived at whether rights are granted to the polluter or to the sufferer as the following paragraphs indicate:

l Suppose polluters have the right to pollute. In this case the sufferers will pay the polluters to clean up to the level where the marginal (additional) abatement cost equals the marginal (additional) reduction cost.

l Suppose sufferers have the right to a pristine environment. Under this arrangement the polluters will pay the sufferers up to the point when it becomes cheaper to clean up emissions than to pay the increasing marginal cost of further damage.

In both cases, the level of equilibrium emission is the same, the ideal, efficient level.

Examples of the Market Method of Regulation

ControllingPollution by Means of a Tax on Production - Under this scheme, the permissible level of pollution is attained by imposing a tax on a unit production of the pertinent product which must reflect the marginal cost of damage associated with a unit output. The additional cost will be charged by the producer to consumers who, in turn, will make a decision on how much to reduce their purchases. The reduction in purchases will cause a reduction in production, hence a decrease in pollution corresponding to the desired level. The higher revenue per unit can then be used for pollution abatement.

Meter and Tux Emission Directly - Under this technique it is necessary to measure directly the amount of emission and impose the tax in proportion to the amount of emission. It is necessary for the tax to reflect the marginal damage cost so that the polluter will be indifferent to paying the tax or abating pollution. This method may be particularly useful in a situation where several polluters of unequal sizes are involved. For instance, in Benguet several mining companies dump tailings in the Agno River. In addition the denuded forests likewise contribute to the same pollution. Above the equilibrium level the polluter would opt to abate emission rather than to pay the tax. The figure also shows the effect of subsidy to abatement. In effect the subsidy encourages abatement such that the firm is willing to pay the cost of abatement up to a point much higher than QE, the equilibrium discharge without subsidy.

Conclusions

This paper has shown a balanced way of viewing the environmental effects of mineral resources extraction and use. On the positive side we see the very crucial role which mining can play in the early stage of the development of a mineral rich country, namely, helping provide the needed foreign exchange, infrastructure, skilled labour, capital, and suitable environment essential for economic growth and development of an underdeveloped economy. In short, if minerals are wisely used they can serve as the fulcrum from which industrialization can take off. As the economy progresses towards the more advanced stage of development, the contribution


of mining to the economy declines, though minerals, whether locally produced or imported, provide an even bigger contribution in a new role as input into the minerals manufacturing sector.

A substantial portion of the paper discussed and illustrated the adverse effects of mineral extraction and use on the physical and biological environment, specifically on the air, water and land. Air pollution consists mainly of dust particles and gaseous emissions like sulphur dioxide, nitrous oxide and carbon monoxide. Major impacts on water resources consist of siltation, chemical and heavy metal contamination and drying of water resources in certain affected areas. Outstanding impacts on land are erosion of top soil, deep or ugly pits, and large piles of waste rocks and tailings which become sources of silt pollution, land slides and subsidence. While these adverse impacts impose their costs on society, there are well known methods of mitigating them such as reclamation and revegetation, which, when properly implemented, can transform the affected areas into forms which are more valuable, pleasing and useful than the original state.

In order to gain an objective method of viewing the good and bad effects of mineral extraction and use, the concept of benefit-cost analysis is introduced, though on an elementary level. In evaluating a policy or a project, the Kaldor-Hicks criterion, which stipulates that the welfare of society increases if in changing from state A to state B, every one is made better off (or at least no one is made worse off), is introduced. Alternatively a change, on balance, benefits society if the total benefits exceed the total costs. Based on these criteria, methods of measuring benefits and costs are developed.

This paper demonstrates an instructional scheme in which the trainees (students) arrive at their own conclusions about certain problemsor issues independently of the trainer (teacher). To do so, the trainer provides an analytical scheme or tool which is used to examine the pertinent facts or data, favourable or unfavourable, on the problem or issue on hand. This method is likely to lead the trainees to conclusions, convictions, or perceptions with which they identify themselves, and to which they are committed.

References

Aisong, Deng. Jan. 1987. Impact of Mine Development on Geological Environment in Tropicrtl and Subtropical Areas of South China ctnd Proposal for Future Management, AGID News, p. 16-24.

Archer, I. Oct. 1984. Revegetntion at Bougcnnville Copper, Mining Magazine, p- 307-313.

Campbell, G.A. 1985. Demands for Miner&, in Vogely, W., Economics of the Mineral In- dustries. New York: AIME.

Fesharaki, F., et al. 1987. Criticnl Energy Issues in Asia and the Pacific: The Next Twenty Years. Colorado, USA. Western Press, p. 70-71,230.

Grigg, C.F.G., 1988. Landscaping Techniques and Restoration, Mining Magazine, Dec. 1988, p. 492-497.

Gulley, D.A. 1985. Environmentnl Regulation and the Mineral Industry in W. Vogely, Economics of the Mineral Industries. New York: AIMPE, p. 601-623.

Gulley, D.A. & B.J. Macy. 1985. Benefits and Costs of Environmental Compliance in W. Vogely, Economics of the Mineral Industries. New York: AIMPE, p. 625-639.


McDivitt, J. & W.G. Jeffrey. 1976. Miner&& Developing Economics in Vogely, W., Economics of the Mineral Industries. New York: AIMPE.

McKern, R.B. & P. Koomsup, ed. 1988. The Minerals Industries of ASEAN and Australirc: Problems ctnd Prospects. Sydney. Allen 81 Unwin.

Miller, S. and J.C. Emerick. 1985. The Secondary Effects of Mineral Development in W. Vogely, Economics of the Mineral Industries, p. 625-639.

Mining Magazine Environmental Benefits of Surface Mining, p. 581-585.

Mining Magazine Landscrrping and Restoration, Dec. 1988, p. 492-497.

Mining Magazine Plants for Bougainville, Oct. 1984, p. 307-313.

Mishan, E-J., 1971. Cost-Benefit Analysis, An Introduction. New York: Praeger Publishers.

Newsweek Magazine Smothering the Waters, April 10, 1989, p. 40-43.

Santos, T.M., V. Abiad & M.S. Delos Angeles. 1982. The Role of Mining in National Develop- ment: The Case of Benguet Province. Taguig, Metro Manila. National Research Council.

Sebua, Ester A. 1989. A Paper on Coastal Ecosystem Prepared for ESE Workshop, p. 9.

Siddiqi, Toufig. 1982. Environmental Aspects of Energy Developments in Fesharaki, F. et al, Critical Energy Issues in Asia and the Pacific, Colorado, USA: Westview Press.

Sweigard, R.J. & R.V. Ramani. Sept. 1986. Regional Compnrison of Post-mining Land Use Practices, Mining Engineering, p. 897 - 904.

Time Magazine Nurture Aids the Alrsknn Clean Up, May 8, 1989, p. 46.

Time Magazine The Two Alaskas, April 17, p. 34-48.

The World Bank. World Trebles 1987. The Fourth Edition. World Bank: Washington D.C., 1987.

Toombs, R.B. 6r P.W. Andrews. 1976. Minerals & Modem Industrial Economics, in Vogely, Economics of the Mineral Industries, New York: AIMPE.

United Nations Committee on Trade and Development (UNCTAD). Commodity Yearbook 1987. United Nations. New York, 1988.

World Mining Equipment Reclnmntion - Some Exnmplesfr-om Europe und North America, Sept. 1986, p. 86-90.

Chapter 11

Environmental Management in the Context of Sustainable Development*

Environment and Sustainable Development

The basic premise behind sustainable development is simple and straight forward: development that destroys the environment is not sustainable. Indeed, the only kind of development that makes sense is development which has sustainable benefits, and such development requires a deliberate effort to protect the natural and environmental base.

Humans have tipped the balance between conservation and development of the natural environment. They must cope with various adverse effects, and act urgently to avert appalling threats to the future. The environmental problems we now face are serious. They are numerous and multifaceted: deforestation; soil erosion; degradation of marine resources; pesticide build- up; domestic and industrial pollution; hazardous wastes; urban blight and more. The central problems are:

l Adverse impacts of growth and development (the so called externalities), such as pollution from factories and pesticide build-up in agriculture; and

l Depletion and degradation of natural resources due mainly to their misuse or overexploitation, such as rapid timber extraction and soil erosion due to improper cultivation practices.

The relationship between environmental protection and development constitutes the core of these problems.

The context in which traditional western approaches to environmental management evolved was, shaped by a high level of development. In that context, the most serious environmental problems were due to the adverse effects of massive industrialization. An environmental movement championed environmental issues by actually opposing further development. The issue came down to choosing between environment and development, and the choice was often fought in adversarial fashion. Unfortunately, this created an impression that environmental advocacy was anti-development. It led many in the Third World to view the environmental movement with initial suspicions. But this impression has now been corrected. We now know

+ Prepared by Bela P. Balagot, Asst. Director, Environmental Management Bureau, Department of Environment and Natural Resources, Philippines.

Pari I - The Knowledge Base 742

that development and environment are not contradictory and that, in fact, they depend on each other.

We also know that the context of economic and environmental problems in developing countries does not warrant a choice between environment and development. Many of the most serious environmental problems in developing countries - soil erosion and destruction of coral reefs, for example - are not caused by economic development or progress as it were, but are the result of activities of countless small farmers and fishermen who are forced by poverty and necessity to exploit the environment in destructive ways. Pollution, misuse of the environment, and poverty are the natural consequences of underdevelopment.

Many pressing environmental problems, in fact, reflect a lack of development. The major causes of environmental degradation in most developing countries are now known to be structural in nature, with roots in poverty and inequity. Therefore, growth must be accelerated, which means actively developing natural resources. More important is that the rewards of growth and development are fairly distributed and that they actually improve the living conditions of the people.

Thus, it is evident that the protection of our environment must take place within the context of development. The question of which should take priority - environment or development - is irrelevant, for experience indicates that one cannot prosper without the other.

Defining Sustainable Development

Sustainable development stresses the need to view environmental protection and economic growth (in terms of growth of per capita real incomes over time) as mutually compatible and not necessarily conflicting objectives. This implies that growth objectives should be compatible with natural resource base limitations and biospherical waste assimilation carrying capacities.

In principle, an optimal policy for Sustainable Development seeks to maintain an “accept- able” rate of growth in per capita real incomes without depleting the stock of natural and environmental resources. Thus, conservation is to be viewed as one of several goals encom- passed by a comprehensive framework for resource management. Its other goals could be the following: resource recovery (recycling of materials/energy in various forms); pollution control (setting of air, water, land quality targets, and the instruments/institutions to achieve the same); and waste reduction (adopting low and non-waste technologies).

In general, the sustainable use of environmental resources can be realized through:

l Maintenance of the regenerative capacity of renewable resources, and avoidance of excessive pollution which could threaten waste assimilation capacities and life support system of the biosphere; and

l Utilization of the growing body of scientific and technological data to foster resource recovery and waste reduction.

If extinctions of renewable resources are to be avoided, harvesting rates should not be greater than the rate of natural growth of the resource over prolonged periods of time. The rate of utilization of such resources should be defined by the level where the rate of “take” equals the rate of renewal, restoration, or replenishment. Thus, in agriculture, the farmer derives fertility from soil equal to the ability of the soil to supply nutrition. Similarly, the forester

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removes trees or tree products at a rate equal to the regeneration. The fisherman catches marine resources in amounts that are equivalent to their replenishment. Natural resource economics has fostered the development of optimal resource management strategies based on this notion of sustainability as “sustained yield” management. This has been found to be generally a prudent basis for long-term management.

Strategies for sustainable development should not neglect the aspects of pollution or residual problems. The accumulation of pollutive substances from specific and diffuse sources results in degradation of the quality of our life support systems.

Natural systems of production are designed for total resource recovery. All material and energy flows balance. Some traditional agricultural systems are patterned after nature. For instance, in some traditional Asian farmsteads, instead of monoculture plantations, a hundred species of useful plants are cultivated, ranging from ground creepers to tall trees. They use all available solar energy, prevent erosion by providing continuous ground cover, and, by their diversity, deter serious pest outbreaks without any pesticide use. Domestic animals feed on plant residues and insects and supply manure for the garden and to fertilize algal growth in fishponds. These farming systems are highly productive and self-sufficient without supplementary inputs.

By contrast, conventional agricultural systems require heavy doses of fossil energy and chemicals, and export massive amounts of topsoil and chemicals and organic residues to the surrounding environment. Similarly, environmental regulations which place emphasis on “end- of-pipe” pollution control systems to treat waste products or standards limiting permissible emissions rate cannot deal successfully with the ever expanding demands placed on the environment by human activities. Sustainable development requires that systems should be designed that will result in resource recovery and waste reduction.

Strategies for Sustainable Development

Several mechanisms have been expounded and applied in some instances to attain better resource management and more sustainable development. They range from major changes in the framework of overall planning and decision-making to the reinforcement or modification of existing policy instruments in resource management.

Economic and Environmental Considerations in Decision-Making

The underlying theme in sustainable development is that economic and environmental concerns are not necessarily conflicting. As pointed out earlier, policies that conserve the quality of agricultural land and protect forests improve the long-term prospects for agricultural development. Efficiency in utilization of energy and raw materials in industrial processes reduces wastes but can also reduce costs. However, due to traditional methods of decision- making which are largely characterized by dealing with one sector in isolation of other sectors, intersectoral linkages are lost in the process. Sectoral agencies tend to pursue sectoral objectives and to treat their impacts on other sectors as side effects, taken into consideration only when forced to do so. Thus, impacts on forests are rarely considered by policy makers in the field of energy, industrial development, or foreign trade.

Merging environment and economics in decision-making involves a fundamental realign- ment of the overall objectives of planning in the light of a new awareness of the environmental implications of development activities. This means that the process of development should be


viewed from the outset as a multipurpose undertaking including an explicit and defined concern for the quality of the environment. Within such a planning context, it is especially important that analysis and evaluation stress the key role that environmental quality can play in sustainable development.

Proper Resource Pricing

The most widespread opportunity to improve resource management is to treat scarce resources as if they were scarce, not as if they were free, by pricing them at the cost of increasing their supply. In essence, this strategy aims to correct the gross underpricing of natural resources (e.g. logs, minerals) that is currently responsible for the rapid extraction and wasteful utilization of these resources. Part of this price reform strategy involves charging a price on those environmental resources (e.g. air, water) which have until now been regarded as free resources and which have thus been polluted freely and indiscriminately.

Thus far, for example, the polluter has viewed the environment as a mere sink, for which he pays nothing to use. We should change this. We should start assigning a social price for these otherwise free resources and induce the polluter to internalize these prices within his private, profit-oriented decision-making. We should make the polluter pay for the social costs of the pollution he creates. The choice is up to him: he can cut down on pollution by investing in pollution controls, or else pay the fair social costs, or even choose some optimum combination of payment and pollution control. In effect, the polluter regulates his own behaviour within the context of an environment pricing system. The system is based on the so-called “polluter pays” principle.

The question of who pays for damages to the environment should be part of a more wide ranging reform regarding the pricing of our natural resources. It has become obvious that our natural resources, for instance our timber and mineral resources, are grossly underpriced; underpriced in the sense that those given the right to exploit these resources for profit pay very little of the significant damage costs to society. They also share with the rest of society very little of the “rents” they get out of exploiting these resources (“rent” represents the surplus after all costs are paid). The rents from the exploitation of our natural resources are huge, and they have gone to only a few. The World Resources Institute, for example, estimated that, of the more than P/20 billion rent from logs harvested in the Philippines from 1979 and 1982, only 12 per cent went to the government (and therefore to society at large).

In general, price reform provides a way to internalize environmental costs as part of decisions on how resources are used. The advantage of a price reform approach to resource management is that, once in place, it provides a self-regulating system. Resource users still make choices in a way that maximizes individual gain, but within a new valuation that recognizes real resource costs.

The strategy does not bank on creating altruistic feelings for the environment as the basis of self-regulation. Rather, by establishing a fair valuation of our resources and charging the users appropriately, we create an automatic economic restraint on the way our environment and natural resources are used.

Property Rights Reform

It has been known for some time that a farmer’s management style on the land is influenced by his tenural status. It follows that security of tenure for small-holder farmers and forest


occupants over primary resources on government lands is a key determinant to the success of environmental protection in these areas.

At a more general level of discussion, we could say that natural and environmental resources have a tendency to be exploited as free resources by individual citizens even though they are scarce resources to the nation as a whole. This is a natural condition for “open access” resources such as our public lands and marine resources. Unlike privately owned resources, open access resources tend to be misused and depleted. It is unreasonable to expect an individual producer, such as a shifting cultivator or a catch fisherman, to conserve the open access resource and one-sidedly regulate his effort, since anything that he consetves will be taken up by others. That, it will be recalled, is the famous tragedy of the commons.

Self-regulation in the exploitation of natural resources can be achieved by assigning secure access rights, perhaps even private ownership, over these resources to individuals and communities. Through these rights, the individual or community establishes a lasting tie with the resource and long term stake in its protection for sustained productivity. Hence, the community or individual becomes self-regulating.

The need now is to develop creative and secure instruments such as forest stewardship contracts, small-holder timber concessions, and artificial reef licenses for ensuring equitable access to the utilization of natural resources. Of course, an essential condition for devolving control or distributing resource rights is for an individual or community to demonstrate capacity to properly manage the resource.

Development of Integrated Protected Areas

Protected areas are established for the conservation of wildlife and unique ecosystems and the conservation of genetic resources for scientific, educational, cultural and historical reasons. The establishment of protected areas should be preceded by a reassessment of the status of parks and equivalent reserves to seive as the basis for intervention strategies for degraded parks while identifying new areas where conservation of genetic resources and preservation of biological diversity may be pursued.

The importance of preservation of wild species and genetic diversity cannot be over emphasized. Our existence today is due primarily to the presence of wild species and their domestic offspring. Agricultural crops and livestock comprising our daily food intake were derived from wild species. Wild species were the basis for many medicines or drugs available today. Many of our necessities, as well as our luxuries, come either directly from wild species or from livestock and crops that are their offspring. Unfortunately, a large segment of the general public seems unaware of their value. This is evident in the lack of concern over the extinction ofwild organisms at an ever-increasing rate. Once extinct these organisms are irretrievably lost, to man’s detriment.

Residuals Management (Pollution Control)

Environmental pollution has been a problem for human beings since they began living together in large numbers in urban areas, but the problem has changed over time and is becoming more complex. This increasing complexity can be attributed to several factors. First, the growth in industrial production, energy conversion, and transport of goods and people is an important factor. These activities have reached levels at which the associated flows of materials


and energy from concentrated states in nature to degraded and diluted states in the environment have begun to alter the physical, chemical, and biological quality of the atmosphere.

Second, many kinds of alien materials are being introduced into the environment. Modern science and technology have subjected ecological systems to foreign substances to which they cannot adapt.

Third, today, people have high expectations of the quality of environment they want to enjoy. There has been in recent years a growing demand for higher environment quality.

The most commonly applied instruments for pollution control are either “end-of-pipe” control systems to treat waste products or standards limiting the permissible emissions rate. Residuals management on the other hand, looks at the pollution problems with an overall framework of materials policy which includes resource recovery, recycling, and by-product design to save materials and energy.

To provide an example, advances in wastewater treatment can be cited. Conventional treatment systems consist of a combination of biophysical and chemical means of disinfecting and removing solids and solid materials from wastewaters. The treated wastewater then passes on to the seas, leaving the problem of disposal of the remaining sludge.

Land treatment of wastewater uses the natural filtration of soils, the bacterial action of soil organisms, and, sometimes, the capability of plants to use the nutrients in wastewater directly. Based on experience derived from utilizing land treatment, the quality of water that has undergone this treatment is equal or better than that of effluent from tertiary treatment in conventional systems. Moreover, there is no problem of sludge disposal, and organic material and minerals in the wastewater are available as nutrients to improve soil quality or stimulate plant growth. Construction and operating costs compare favourably with conventional systems, while total systems costs are lower.

Recent innovations in industrial process designs have been aimed at reducing waste streams, as restrictions on disposal grow. Reformulating products, developing saleable by- products from residuals, and redesigning or combining processes often reduce costs as well as wastes. For example, a U.S. poultry plant cut water use by 32 per cent thereby reducing wastes by 64 per cent. The use of biogas digesters to recover methane from piggery or distillery wastes is another example of reducing wastes through technological innovations.

In the developing countries, resource recovery is highly economical because materials and energy costs are high relative to labour costs. Paper, glass, metals, plastics, oils and other materials are recovered from waste streams and recycled by networks oE workers.

Environmental Education

In general, the primary aim of environmental education is to enable citizens to understand and appreciate the complex nature of the environment, as well as the role played by a properly managed environment, in economic development. Only an informed, motivated and committed citizenry could provide the mass base necessary for the continued protection of the environment. On another level, environmental education can be instrumental in increasing environmental awareness among top policy makers in government. Decisions are ultimately a political responsibility, but the likelihood of the best choices being made is greatly enhanced when there is widespread knowledge and understanding of all the implications. So education, both formal and non-formal, has an indispensable contribution to make. The task of education


is to develop a rational basis for the study of the environment, and thus equip people to make up their own minds in an informed way.

Strengthening of Citizens’ Participation

Over recent years, the increasing challenge to identify missing factors to contribute towards sustaining resource management efforts has brought to light the significant role of community participation in sustainable development programmes.

Community-based sustainable development programmes work on the basic premise that people have the innate capacity to improve their quality of life and the problems confronting them can be overcome through their own efforts with some assistance from government and non-government agencies.

In promoting the active participation of the citizenry for sustainable development, non- government organizations can be the central vehicle in mobilizing people to participate, since they are the segment of population which will work through community organizing, public informaion campaigns, research/situation assessment, environmental surveillance and monitoring.

Proper management of the environment (Banane Rice Terraces, Ifugao, Philippines)

Chapter 12

Environmental Management and Impact Assessment*

The concept of environmental management has evolved through the years. Consequently, there have been corresponding changes in the policies and strategies in this field. One of the basic premises in environmental management today is the recognition that environment and development are not exclusive of one another but are complementary. This concept is based on an understanding of interdependency between environment and development.

We all take cognizance of the fact that environmental problems should be viewed as a system and that we cannot compartmentalize environmental concerns into sectors. This means that for environmental management to be effective, environmental concerns should be integrated at all levels of development planning. However, as the growing environmental crisis shows, it is very difficult to give operational content to this concept. Thus, we continue to abuse and misuse the very environmental resources upon which life depends as evidenced by the severe soil erosion of agricultural lands, the pollution of our rivers and air, deforestation, desertification and other adverse environmental phenomena.

A constraint in the definition of practical policy guidelines for integrating environment in development planning is the fact that the causes and effects of environmental problems are complicated and oftentimes unmeasurable. Environmental impacts are frequently synergic. They could be irreversible and in most instances difficult to predict.

Environmental impacts have economic values associated with them. For instance, the effect of soil erosion may be measured from the point of view of agricultural productivity, that of air pollution in terms of human health, etc., but the problem is to put a price tag on them to make them comparable and commensurate with the costs and benefits of environmental protection measures.

To this end, it is necessary to refine existing analytical tools and methodologies to enable decision-makers to accommodate the social and environmental consequences, in addition to the purely economic ones, of development activities. One of the most effective tools for this purpose is environmental impact assessment.

* Prepared by Dr. Beta P. Balagot, Assistant Director, Environmental Management Bureau, Department of Environment and Natural Resources, Philippines

Part I - The Know/edge Base 150

Purpose and Scope of Environmental Impact Assessment (EIA)

EIA is an activity designed to identify, predict, and describe in appropriate terms the costs and benefits of a proposed action. It is used to identify, predict and assess the likely primary and secondary changes that may arise from a proposed development activity and then, as systemati- cally and effectively as possible, to present the results for review and decision.

EIA is best considered as part of the overall planning process and not as a separate discrete assessment exercise. The primary objective for adopting EIA is to aid decision-making. It is this broader viewpoint that differentiates the process from being a purely scientific study and gives it an operational cost.

Reasons that have been advanced for introducing EIA are that the increasing scale of resource development schemes and their resulting impacts to the physical environment and communities could no longer be ignored, and the traditional appraisal techniques were inadequate to deal with various environmental and social issues, particularly those having long-term consequences.

The objective of any EIA requirement is to promote and ensure that planning decisions take into account environmental costs and benefits. In practice, its effectiveness in influencing decision rests on the following assumptions:

l Interested public or regulatory agency scrutiny of environmental issues disclosed by the EIA will reinforce accountability of decision making process;

l The process can order information on environmental impacts along with economic and technological issues so that more decisions can be made by the project proponents.

Components of EIA

Once the alternatives (including the “no action” alternative) to be subject to EIA have been selected, the main components of the EIA process are:

1. Impact identification;

2. Impact prediction and measurements;

3. Impact interpretation and evaluation;

4. Identification of monitoring requirements and mitigating measures;

5. Communication of impact information to users such as decision-makers and members of the public.

Impact Identification

This activity aims to identify likely impacts which need to be investigated in detail. At first glance it seems to be an easy task, but, in practice, there is lack of knowledge concerning the nature and extent of impacts arising from the variety of developments which are located in different environmental settings. For example, impacts of a particular type of project in one location may be different from those arising from an identical installation in another environment.

Management and Impact Assessment 151

Experience has shown that the main problem in impact identification is the tendency to identify all possible impacts and to investigate them individually. It is therefore necessary to establish which are the primary impacts that need to be investigated further. This process is referred to as scoping. It involves discussions, frequently in the form of meetings, between those implementing EIA, the project proponent and representatives from other government agencies which have an interest in a development proposal and members of communities to be affected by the project. Scoping is of crucial importance in situations where resources of EIA are limited. It also minimizes or prevents public opposition at a late stage in EIA which would mean costly delays, design changes and additional work.

t impact Prediction and Measuremen!

This involves an estimation of the likely nature or characteristics of impacts in quantitative or qualitative terms. For example, for a project involving the establishment of a pulp and paper mill, impact prediction and measurement entail calculation of, among other things, noise levels at the nearest inhabited site, concentration of sulphur dioxide at varying sensitive locations, and changes in downstream oxygen as a result of the discharge of aqueous effluent with a high organic loading.

The next stage after measuring the likely changes that will occur is the determination of the nature of these effects on humans, animals or plants. In cases where dose-response curves are available, this is easily done. Unfortunately, these do not usually exist, and experts can only make an estimate or educated guess of the effects of a particular pollutant concentration on individual organisms, on populations and on communities of organisms. This is probably one of the most difficult activities within EIA.

Impact Interpretation or Evaluation

This activity consists of determination of the importance of an impact and determination of relative importance of impacts when compared with each other.

For example, the construction and operation of a factory will increase the noise level by lo-15 dB(A) in the nearest community. How important is this change in noise level? Evaluation involves expressing impacts in economic terms, but EIAs constantly investigate a number of impacts which cannot easily be expressed in common units (such as money) and thereby comparisons cannot be directly done. The canvassing of informed technical opinion, information from advisory bodies and even from the general public may be the limit of the ability to evaluate impacts in many cases.

Identification of Monitoring Requirements and Mitigating Measures

Once likely harmful impacts have been identified, possible measures to mitigate them should be investigated and their ability to produce the desired objectives should be assessed. There is a need for monitoring during construction and implementation of the project for the following reasons:

a. To ensure that legal standards for effluents are not exceeded;

b. To check that mitigating measures are implemented in the manner described in the EIA and related documents;


c. To provide early warning of environmental damage so that actions may be taken if possible, to prevent or reduce the seriousness of the unwanted impact, and also to check the accuracy of impact predictions made prior to a decision to authorize a project.

Application of knowledge from impact monitoring can improve the accuracy of future EIAs by indicating those predictive techniques which are the most successful and those impacts actually found to have occurred.

Communication of Impact Information

It is essential that quantitative and qualitative information on impacts be presented in a form that enables non-experts to comprehend them. Unless this is done, interested members of the public and decision- makers will be unable to form conclusions on the merits and disadvantages of a proposal.

EIAs must produce answers even when there is imperfect knowledge. Where a potential effect is identified, but prediction and evaluation are known to be inadequate, the answer must be to communicate to the decision-maker that the risks associated with that effect are unknown. The decision maker then has the options of:

a. Ignoring the potential effect;

b. Modifying the project to carry out further research to establish the magnitude of the effect with more certainty; or

c. Abandoning the project.

The design of projects (and generation of options) is iterative or cyclic. A planner or designer works through a procedure of trial and error in arriving at a preferred plan. If information from an EIA is available during an early stage of this process it has some chance of being incorporated. However, once a final plan has been arrived at in the absence of this information, it is unlikely that environmentally desirable modifications will be incorporated without considerable difficulty and contest. This is a further commentary on the appropriate timing of EIA and interaction with the planners.

EIA Methodologies

Numerous techniques and methods have been developed since the advent of EIA in the 1960s for evaluating and presenting the impacts of developmental activities. These methodologies display variety in conceptual framework, data format, data requirements, manpower, monetary and time resource requirements. Among the more important techniques and methodologies which have been applied in developing countries are:

l Ad hoc

l Checklists

l Matrices

l Network

0 Overlay

l Simulation modelling


The Ad Hoc Method

This methodology gives broad qualitative information of value in the comparative evaluation of alternative development actions. The information is stated in simple terms that are readily understood by the lay decision-maker or the public without outlining the actual impacts on the specific parameters which will be affected.

The ad hoc method merely presents the pertinent information of the project’s effect on the environment without resorting to any relative weighing. For example, it may state the number of people who are likely to be affected adversely, or the area1 extent of impacts arising from a project.

Thus, this methodology provides minimal guidance for impact analysis beyond suggesting broad areas of possible impacts. Being a very simple method, it is very easy to use but has certain drawbacks such as:

a. It gives no assurance that it encompasses the comprehensive set of all relevant impacts;

b. It lacks consistency in analysis as it may select different criteria to evaluate different groups of factors;

c. It is inherently inefficient as it requires sizeable effort in identifying and assembling an appropriate panel for each assessment.

An example of the use of the ad hoc method for comparing alternative reservoir arrangements is given in Table 12.1. It can be seen that it gives a cursory glance of the different types of impacts of the various alternatives of the project in an easily understandable manner. It should be noted, however, that it is not a recommended method for assessing impacts.

Checklists

These represent one of the most basic of all methodologies in impact assessment. Check- lists present a specific list of environmental parameters that are to be investigated and evaluated. They are more comprehensive than the ad hoc method in that environmental parameters that are likely to be affected by the project actions are listed and rated subjectively on their magnitude. Again, like the ad hoc method, it does not show cause-effect relationship between project actions and environmental parameters.

The three broad categories of checklists used in practice are:

1. Simple Checklists: This is merely a list of parameters, but no guidelines are provided on how environmental parameters are to be measured and interpreted. (Table 12.2)

2. Descriptive Checklists: This includes an identification of environmental parameters and guidelines on how data on the parameters are to be measured. (Table 12.3)

3. Scaling Checklists: This is similar to the descriptive checklist, but with additional information on the subjective evaluation of each parameter with respect to all the other parameters.


Table 12.1. Illustration of Ad Hoc method for comparing alternative reservoir arrangements

Item

Number of reservoirs on river system

Combined surface area, ha

Total reservoir shoreline, km

New irrigation areas, ha

Reduced open space because of project and associated population increase, ha

A

4

8,500

190

40,ooo

10,ooo

Inundated archaeological sites, nos.

Reduced soil erosion, relative magnitude

11

4x

Enhanced fisheries, relative magnitude

4x

Provision of flood control measures

New potential malarial areas, relative magnitude

Yes

4x

Additional Employment potential, number of persons

Matrices

/ Altetative / c

65

lx

IX

Yes

lx

Nil

Nil

No

Nil

Matrix methods are basically generalized check-lists in which possible project activities are established along one axis, with potentially impacted environmental characteristics or conditions along the other axis. In this manner, cause and effect relationships between particular project activities and impacts are identified.


Tuble 12.2. Checklist for Huasai - Thlde Noi road project

f

Nature of Likely Impacts I

Adverse 1 Beneficial Items

ST

Aquatic Ecosystem

Fisheries

Forests

Terrestrial Wildlife

Rare & Endangered Species

Surface Water Hydrology

Surface Water Quality

Ground Water *

Soils

Air Quality X

Navigation

Land Transportation

Agriculture

Socio-Economic

Aesthetic

Legend:

ST - Short Time LT IR - Irreversible R

N - Normal W SI - Significant * L - Local

Source: Lollarti, 1983.

- Long Term - Reversible

- Wide

- Negligible


Tuble 12.3. Checklist for the Malabon Basin wastewater treatment system

No. Question

Ans. Impact type Duration Rever- Severity Specifications sibility

NO YES (for YES only) D ID SY L S R IR N SV

A. NATURAL BIOLOGICAL ENVIRONMENT

1. Might the proposed X Surface water X X X X

activity affect any natural quality features or water resource adjacent to or near the Soil/Erosion X X x x activity area? (If yes, specify natural features affected).

2. Might the activity affect Ecology of fisheries X X X X wildlife or fisheries? (If yes, specify wildlife or fisheries affected).

3. Might the activity affect X Natural vegetation, X x x X natural vegetation? timber (If yes, specify vegetation affected). (If yes, specify

whether any race or endangered plant species might be affected): none

B. ENVIRONMENTAL HAZARD

1. Might the activity involve the use, storage, release of, or disposal of any potentially hazard substance? (If yes, specify substance and potential effect)

X

2. Might the activity cause an X increase or probability or increase of environmental hazard? (If yes, specify type).

3. Might the activity be X susceptible to environmental hazard due to its location? (If yes, specify type).


Table 12.3. Checklist for the Malabon Basin wastewater treatment system (cont’d)

No. Question

Ans. Impact type Duration Rever- Severity Specifications sibility

NO YES (for YES only) D ID SY L S R IR N SV

1. Might the activity affect or X Pond X X X X

eliminate land suitable for agricultural or timber Right of way X X X X

production? (If yes, specify areas and soil class which will be affected).

2. Might the activity affect X Manila Bay X X commercial fisheries or Fisheries agricultural resources or production? (If yes, specify type affected).

3. Might the activity affect the X potential use or extraction of an indispensable or scarce mineral or energy resource? (If yes, specify resource affected and approximate amount). m-

Legend: D(direct); ID(indirect); SY(synergistic); L(long term); S(short term); R(reversible); IR(irreversible); M(moderate); SV(severe).

The entries in the cells of the matrix may be either qualitative or quantitative estimates of these cause-effect relationships. If the latter is the case, it may then be combined into a weighing scheme so as to produce a total impact score. Matrices can be tailor-made to suit the needs of any type of project that is to be evaluated and should preferably cover both the construction and the operational phases of the project, because sometimes the former causes impacts larger in scale and magnitude than the latter.

Essentially, there are two kinds of matrices in use: the simple interaction matrix; and the quantified and graded matrix. The simple, interaction matrix gives an idea of the potential impacts of each project sector on each environmental parameter by means of a qualitative judgement of the analyst. Quantification can be incorporated by extending judgement to denote the “magnitude” and “importance” of the impact of each cell of the matrix, so as to prepare a matrix in which quantitative gradation between the various impacts of project actions on environmental parameters can be observed.

Pat-f I - The Knowledge Base 158

Network Methodologies

Network methodologies work from a list of project activities to establish cause-condition relationships. They are an attempt to recognize that a series of impacts may be triggered by a project action. The approach is generally to define a set of possible networks and allow the user to identify impacts by selecting and tracing out the appropriate project actions. Networks were originally developed expressly for coastal zone planning, and for addressing two issues especially pertinent to this zone: resolution of conflict among competing uses; and control of resource degradation.

The basic network method is derived from studies of ecological energetics. The procedure begins with a list of environmental attributes. These are linked by solid lines in a large diagram which shows the direction and magnitude of energy flows between all component activities associated with a particular project likely to cause impacts are included in the systems diagram.

Working from the systems diagram, environmental attributes arc examined in three aspects: initial condition (or first-order, direct impacts); consequent condition (or second-order, and third-order impacts); and environmental effects. “Effects” in this context are actual use conflicts or resource changes that might contribute to a loss of environmental quality. A fourth, optional consideration of each attribute pertains to mitigation measures or control mechanisms.

A network method may be best suited for single project assessment, and is not recommended for large regional actions. In the latter case, the display may sometimes become so extensive that it will be of little practical value, particularly when several alternatives are being considered.

The Overlay Approach

These methodologies use a set of transparent maps of a project area’s environmental characteristics (physical, social, ecological, aesthetic). In general, the study area is subdivided into geographical units, topographic features, or differing land uses. Within each unit, information is collected on a variety of attributes subdivided among the categories of climate, geology, physiography, hydrology, soils, vegetation, wildlife habitats, and land use. Within each category those attributes most relevant to a particular problem are considered. In practice, attributes are often measured on an ordinal scale. For example, the incidence of water pollution may be measured as high, medium, or low.

For each attribute, a transparent map is considered using gradations of colour to indicate area1 extent and value rating within a geographical unit. All maps are then superimposed to produce a composite of all attributes. With this series of overlays, land use suitability, action compatibility and engineering feasibility are evaluated visually, in order to identify the best combination. In recent years, overlay techniques using computer mapping to analyze data and search for areas of least impact have been developed.

The overlay approach is generally effective in selecting alternatives and identifying certain types of impacts, land use conflicts, or trade-offs, in their spatial dimension. However, the method does not lend itself to any measurement or expression of the magnitude of impacts, nor to the identification of secondary and tertiary interrelationships among impacts. Many social and economic values are not considered. Since there is a limit to the number of transparencies which can be viewed simultaneously, the approach is self-limiting. In practice, overlay methodologies are rarely used as the sole bases of environmental assessment. However, they can serve as very important techniques for decisions involving site selections for large or potentially hazardous facilities such as power plants or waste disposal sites.

Management and impact Assessment 159

Simulation Modelling/Adaptive Environment Assessment

Modelling methodologies for impact assessment, as they have been developed in recent years, have been designed to provide holistic approaches to the assessment process. Specifically, the Adaptive Environmental Assessment (AEA) procedure developed by Holling and co- workers is intended to be used both for planning and for actual management of the resource area modelled. In this way, the model serves less as an assessment of individual projects, and more as a tool to integrate impact analysis into large-scale plan and project formulation and execution.

Central to the EIA process are workshops and extensive communication among a selective group of specialists and managers. The entire procedure is intended to be very flexible and adaptable to the varying needs of assessment.

Initially, a project manager sets up a study team consisting of biologists, economists, and other specialists, with a support staff having skills in ecology and modelling. A core from the study team runs workshops, constructs conceptual or computer models and produces analytical output from alternative runs, while other specialists are called in as needed. Three or so workshops are held in the course of the process, involving all specialists and, ideally, representatives of environmental agencies.

The first workshop serves to define and find the problem, and begin identification of model components. By the time of the second workshop, the core group is expected to have refined the rough model developed at the first workshop to the point that impactsof alternative policies can be analyzed. In the second workshop major data gaps are identified, and decisions are made on research plans and management options to be tested. In the period following this workshop specialists work to improve the data base, gathering new data if necessary, and to further refine and simplify the model. When the model is satisfactorily functional, the third workshop convenes for about a week to make final revisions, incorporate new data, and evaluate alternatives through operation of the model.

After the final reading, the remaining months involve completion of an alternative run, production of information packages, and description of the outcomes of various alternatives. The AEA process is a response to criticism of impact methodologies which assume unchanging conditions, projecting impacts in single timeframe statistically-described environmental conditions. The AEA approach explicitly includes data and facilities for handling ecosystem trends and dynamics, enabling particular projects or plans to be assessed in the context of continual change and higher-order interactions.

The major shortcoming of the method is that it may be a time consuming and expensive procedure for synthesis of environmental information. The method depends heavily on a small group of experts, and has no provision for public input. It appears that AEA is most applicable in the formulation and assessment of alternative strategies to solve resource management problems, where a limited number of objectives are being considered.

Choosing Methodologies

Each of the different methodologies for the assessment of environmental impacts of developmental activities have their advantages and disadvantages and their usefulness for a particular application is largely a matter of choice and judgement by the analysts. The trend is towards moving away from mere listing of potential impacts towards more complex areas


whereby it can identify feedback paths of higher order impacts and can incorporate uncertain- ties.

In the selection of appropriate methods for application, two underlying perspectives must be borne in mind on the utility value of EIA. The first perspective is one that views EIA as an analytical technique and considers the evaluation of impacts of project activities on the total environment to be a highly complex and complicated procedure. This view holds that responsibility for conduct and review of EIAs should be the field of scientific experts. It also holds that quantification should be accomplished to the maximum extent possible and that the element of decision-making should be incorporated in EIA

A second perspective holds that the primary utility of EL4 is its being a vehicle for communication with affected groups. This perspective suggests that, due to the lack of required information, decision-making should not be restricted to scientific opinions but should include social and cultural values.

References

Biswas and Qu, ed. 1987. ELA Methodologies for Developing Countries.

Canter, L.W. 1977: Environmental Impact Assessment. N.Y. McGraw-Hill.

C.S. 1979. Adaptive Environmental Assessment and Management. N.Y. Wiley.

Hufschmidt, M.M., James, D-E., Meister, AID., Bower, B-T., and J.k Dixon. 1983. Environ- ment, Natural Systems and Development. Baltimore, The John Hopkins University Press.

Interim Mekong Committee, 1982. Environmental Impact Assessment, Guidelines forApplica- tion to Tropical River Basin Development. Bangkok, UNEP.

Lohani, B.N. and N. Halim, 1983. Recommended Methodologies: Rapid Environmental Impact Assessment in Developing Countries: Experiencesf,-om Case Studies in Thailand. Bangkok, UNEP.

.

c


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Chapter 13

Developments in Environmental Education*

Environment encompasses two basic facets - the biophysical and the sociocultural. The first covers the biological and physical aspects and the second, human’s economic, social, political and intellectual activities. Thus, the concept of the environment in its totality is a complex one, far-ranging in its implications, and challenging to human’s understanding.

Environmental Problems

The human intervention in natural processes during the past few decades has created environmental problems of serious magnitude. After a century of swallowing noxious fumes emitted into the atmosphere by automobiles, industries and power plants, mother nature has begun to show signs of sickness and serious global damage. Acid rain is destroying forests thousands of miles from the coal-fired power plants. The ozone in the upper atmosphere that protects all life from the sun’s harmful ultraviolet rays is being depleted by chemicals released from air conditioners, refrigerators, styrofoam, aerosol sprays and other products. The extensive destruction of forests by illegal cutting and clearing for shifting cultivation, increasing agricultural land area, firewood and charcoal, and forest-product trade is causing many problems. These include soil erosion, desertification, climatic changes, floods and an increased concentration of carbon dioxide in the atmospere leading to its warming up through the “greenhouse effect”. The greater frequency of droughts, heat waves and floods during the past few years is an indication of the effects of deforestation and pollution. Five of the hottest years of the past century have occurred in the 1980’s. Records show that earth’s atmosphere is now about 0.5 degree Celsius warmer than 100 years ago. The warmest period in history was between 6000 to 2000 B.C. when the temperature was about 1 to 2 degree C higher than today. The Little Ice Age (about 1550 to 1700 A.D.) was a few tenths of a degree cooler. These small variations in temperature had a significant impact on weather, agriculture, and even the development of civilizations. Most models suggest that, due to the increase in temperature, sea level will rise about 30 centimetres by the mid 21st centuty, but the rise could be as much as one meter due to melting of arctic ice sheets and alpine glaciers. This rise in sea level would flood many coastal regions, hasten shore erosion, and contaminate irrigation and drainage systems with sea water. Overall average precipitation around the world will rise, leading to an increase in snowfall in some regions during winter and floods and droughts during summers in other regions.

l Paper by Dr. R.C. Sharma, Regional Advisor for In-school Population Education, Unesco PROAP, Bangkok.

-w- .-

Part II - Pedagogical Aspects 164

An assessment by UNEP in 1984 revealed that about 4 000 million hectares of the world’s rangelands, rain-fed croplands and irrigated lands - an area approximately the size of North and South America combined - is affected by desertification. Currently each year some 21 million hectares are reduced to a state of near or complete uselessness. Projections to the year 2000 indicate that a loss on this scale will continue if nations fail to step up remedial action to combat this destruction of forests.

In an effort to improve the pace of development, many countries are now turning to the use of nuclear energy as a substitute for oil. By the year 2000 the use of nuclear energy will significantly increase. Several hundred thousand tonnes of highly radioactive spent nuclear fuel will be generated over the lifetimes of the nuclear plants likely to be constructed through the year 2000. The nuclear power production will create millions of cubic metres of low-level radioactive wastes, and uranium mining and processing will lead to the production of hundreds of millions of tonnes of low-level radioactive tailings. It has not yet been demonstrated that all of these high and low-level wastes from nuclear power production can be safely stored and disposed of without incident.

The recent industrial accidents in Seveso (Italy), Bhopal (India) and Chernobyl (USSR) have brought a great deal of death, injury and disease to human and animal life. All these accidents have highlighted the threats that certain industries pose to human life and the quality of the environment unless they are operated under very strict safety conditions.

According to the Red Data Book issued by the International Union for Conservation of Natural Resources (IUCN), 1 000 species of birds and mammals are currently threatened with elimination. IUCN estimates that 10 per cent of the species of flowering plants are also threatened with elimination. An estimate prepared for the Global 2000 Study suggests that between half a million and 2 million species - 15 to 20 per cent of all species on earth - could be extinct by 2000, mainly because of loss of wild habitat but also in part because of pollution. Extinction of species on this scale is without precedent in human history.

During the past few years, there has been a lot of discussion on the relationship between environment and development. It is now recognized that where poverty is widespread and large numbers of people do not have adequate food, shelter, health care, education or proper employment, sheer lack of development may degrade the quality of life more than the adverse environmental impacts of development. The grinding and pervasive poverty in the developing nations has been referred to as the “pollution of poverty”, while the widespread neglect of the environment and the erosion of social values in the developed nations has been described as the “pollution of affluence”.

Garrett Hardin’s analysis of the “Tragedy of the Commons” has become a classic statement to explain the over-consumption of resources. Using the analogy of the common pasture land of historic English villages, he argues that “the carrying capacity of such common resources will be exceeded when individuals act in an economically rational manner. Thus, to maximize immediate welfare, each herdsman places additional cows on the pasture, since the benefits (additional milk, beef, profits, etc.) accrue directly to him while the costs of additional grazing are shared with all other herdsmen. In short, the rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. But his is the conclusion reached by each and every rational herdsman sharing a common. There is the tragedy. Each man is locked into a system that compels him to increase his herd without limit - in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own interest in a society that believes in the freedom of the commons. Freedom in a common brings ruin to

Developments in Environmental Education 165

all.” The “Tragedy of the Commons” is analogous to a wide range of complex problems which we are facing today.

In fact “Consumption Explosion” is mainly happening in the developed countries. The developed countries with only about 25 per cent of the world’s population consume about 75 per cent of the world’s resources.

Therefore, one of the most fundamental problems confronting us today is how to meet the basic needs and requirements of all people on earth wihout seriously destroying the resource base - the environment - from which these needs ultimately have to be met. Hence, an understanding of the interrelationship between environment and development is essential for the successful implementation of any strategy for the protection and management of the environment.

International Actions

Anumber of environmental and ecological disasters that occurred in 50’s and 60’s attracted public attention to take some concerted steps to solve the problems of increasing environmental pollution. The smog episodes in London during 1950’s and 1960’s, the mercury poisoning in Minamata, Japan between 1953 and 1965, the ecological damage caused in U.S.A. by the use of DDT and other organochlorine pesticides were some of the more serious environmental incidents which focused public attention on the environment. Although the United Nations Conference of Human Environment held in Stockholm in 1972 is generally considered the first concerted international attempt to address global environmental problems, some international organizations such as Unesco, FAO, WHO, World Meteorological Organization (WMO) and some non-UN bodies such as Organization for Economic Cooperation and Development (OECD), Council for Mutual Economic Assistance (CMEA) and Council of Europe had been involved in studying environmental problems for several years. The early international programmes such as International Geographical Year of 1957 and 1958, the Scientific Committee on Antarctic Research and the International Biological Programme gave impetus to environmental status in general and helped popularize environment issues, especially in the developed countries like U.S.A., USSR, and Western Europe.

The Stockholm Conference provided a forum and a focus for the major problems of the human environment: pollution, environmental health and the need for promoting awareness of the environmental issues. It pointed out that the world was facing a problem of incalculable and often irreversible harm that man had inflicted on the natural environment.

In response to the historic developments of the early 1970s and the growing need to grapple with the network of problems underlying environment, resources, population and development, a series of international conferences were held by the United Nations subsequent to the Stockholm Conference on Human Environment. Some of these were: The United Nations World Population Conference (August 1974); the World Food Conference (November 1974); the Second General Conference of the United Nations Industrial Development Or- ganization (March 1975); the United Nations Conference on Human Settlements (June 1976); the United Nations Water Conference (March 1977); the United Nations Conference on Desertification (September 1977); the United Nations Conference on Science Technology for Development (August 1979); the United Nations Conference on New and Renewable Sources of Energy (August 1981) and the World Population Conference (August 1984).

---..-.


Developments in Environmental Education

The Stockholm Conference produced an action plan for human environment and resulted in the establishment of United Nations Environmental Programmes (UNEP) which, together with Unesco, launched the International Environmental Education Programme (IEEP). IEEP organized an International Workshop on Environmental Education in Belgrade in October 1975. The results of the deliberation of this workshop were contained in a document - the Belgrade Charter - which spelled out a framework and statement of objectives and guiding principles for environmental education. The Belgrade workshop was followed by a series of regional meetings held in Brazzaville for Africa, Bangkok for Asia, Kuwait for Arab States, Bogota for Latin America and the Caribbean, and Helsinki for Europe. The Asian Regional Meeting which was held in Bangkok in November 1976 resulted in formulation of 15 recommendations under the following four problem areas: programmes for environmental education; personnel training; non-formal environmental education; and materials for environmental education.

The regional meetings were followed by the Inter-governmental Conference on Environ- mental Education which was held in Tbilisi, Georgia, USSR in October 1977. The meeting marked the culmination of the first phase of the environmental education programme. At- tended by representatives from 66 Member States of Unesco, the Conference was highly significant in the development of environmental education. Following the Tbilisi Conference, the Member States reacted positively by undertaking the development of environmental education and by introducing legislation to protect the social and physical environment. As a follow-up to the Tbilisi Conference, a Regional Workshop on Environment Education was held in Bangkok in September 1980. This workshop was attended by 19 participants from 17 Member States and made specific recommendations for implementing environmental education programmes in the Asian region.

In 1981/82 the joint Unesco/UNEP International Environmental Education Programme (IEEP) conducted a survey to determine the present needs and priorities of Member States in relation to environmental education and training and the main trends in its development, particularly since the 1977 Tbilisi Conference.

This survey showed that in the Asian region the most pressing needs in environmental education are felt in: secondary education; teacher-training; university education; technical and vocational education; general primary education; adult education; and rural education. The most marked shortcomings in this respect are related to appropriate teaching materials, the number of teachers qualified to deal with curricula in this field, curricula in the field of environmental education and research and experimentation. A very high level of priority was accorded to the training of teachers in the fields of: environmental education; university education; technical and vocational education; and general secondary education. A considerable level of priority was accorded to adult education, moral education and general primary education. High priority was also attributed to the following environmental problem areas: conservation of resources; pollution and nuisances; nutrition and health; urban environment; and the problem of natural disasters.

Since the establishment of IEEP in 1975, over 130 countries have been involved in its activities. It has produced two source books on formal and non-formal environmental education, prototype modules for formal education and teacher training, a guide on environmental education methodologies, an audio-visual package etc.


Unesco-UNEP International Congress on Environmental Education and Training was held in Moscow, USSR from 17-21 August 1987, and was attended by over 300 specialists from 100 countries and observers from IUCN and other international organizations. This Congress outlined an international strategy for action in the field of environmental education and training for the 1990’s. The Conference set the nine objectives and actions for the international strategy for the 1990s:

Objective 1: Access to Information.

Strengthening of the international system for information and exchange of experience of the International Environmental Education Progrmme (IEEP).

Actions: Setting up a computerized service; Strengthening regional networks of institutions of excellence and documentation centres; Publication of the newsletter ‘Connect”.

Objective 2: Research and Experimentation.

Strengthening of research and experimentation on educational content and methods and strategies for the organization and transmission of messages concerning environmental education and training.

Actions: Research and experiments concerning educational content and methods; Re- search and experimentation concerning other complementary aspects of environmental education; Research concerning the pedagogical approach to the question of values; Research concerning new strategies for the transmission of messages to develop environmental awareness, education and training; Comparative evaluation research on the different components of the educational process.

Objective 3: Educational Programmes and Teaching Materials.

Promotion of EE through the development of curricula and teaching materials for general education.

Actions: Exchange of information on curriculum development; Development of model (prototype) curricula; Development of new teaching aids; Promoting curriculum evaluation.

Objective 4: Training of Personnel.

Promotion of pre- and in-service training for qualified formal and non-formal environmental education personnel.

Actions: Promoting pre-service training; Promoting in-service training.

Objective 5: Technical and Vocational Education.

Incorporation of an environmental dimension into technical and vocational education.

Actions: Development of programmes and materials for education and training; Training and developing the awareness of teachers; A priority activity in the service sector.

Objective 6: Educating and Informing the Public.

More effectively educating and informing the public about the environment through the use of the media and the new communication and information technologies.


Actions: Producing media-related education programmes; Use of new communication media and activity teaching methods; Creation of a bank of audiovisual programmes; Develop- ment and use of exhibitions and museums; Developing Unesco-UNEP joint activities.

Objective 7: General University Education.

More effective incorporation of the environmental dimension into general university education through the development of study programmes, teaching materials and training, and through the establishment of appropriate institutional machinery.

Actions: Developing the awareness of academic authorities; Development of study programmes; In-service teacher training; Institutional intra-university cooperation.

Objective 8: Special Training.

Promoting specialized scientific and technical environmental training.

Actions: Initial training for environmental specialists; Further training for professionals including decision makers and administrators; Training through research; Development of suitable study programmes; Use of natural parks, biosphere reserves and other protected areas; Strengthening regional training capacity.

Objective 9: International and Regional Cooperation.

Development of environmental education through coordinated international and regional cooperation.

Actions: Exchange of information; Promotion of research and experimentation; Promot- ing training; Study programmes; Information on legislation concerning environmental education, natural resources and environmental management; Regional action within the framework of JEEP; Mobilization of technical and financial resources; Inter-agency coordination and consultation at the international level; World Decade for Environmental Education, 1990-2000; International congress on EE and Training for the beginning of the twenty-first century.

In view of the fact that worldwide development of environmental education is a lengthy and complex process, the Congress considered it desirable to designate 1990-2ooO as the “World Decade for Environmental Education”. The programmes developed for this decade should emphasize the interrelationships between people and the biosphere in their full range of economic, social, political, cultural and ecological dimensions. It is envisaged that another international congress on environmental education and training will be held in 1997 to take stock of the progress made after the Moscow Congress, and to draw up priorities, means and actions for the first decade of the twenty-first century.


References

Calhoun, John B (Ed.): Environment andpopulation. New York. Praeger, 1983.

Eckholm, Erik P.: Losing ground; environmental stress and world food propsects. New York, W.W. Norton, 1976.

Down to earth: environment and human needs. London, Pluto Press, 1982.

Marde, Parker G. and Dannis Hodgson:‘Population, environment and quality of lt$e. New York, AMS Press, 1975.

Population Bulletin, Population Reference Bureau. Issues on: Resources, environment and population; the nature of future limits. Vol. 34, No. 3, August 1979.

Ramana, D.V.: An overview of environment and development: Asia and the Pacijic. Bangkok, UNAPDI, 1980.

Salas, Rafael M.: Managing the environment, Populi. Vol. 9, No. 3., 1982.

Sharma, R.C.: Population, resources, environment and quality of life. Delhi. Dhanpat Rai & Sons., 1988.

Unesco: Trends in environmental education. Paris, 1977.

Unesco-UNEP. Report of Unesco-UNEP Congress on Environmental Education and Training, 17-21 August, 1987. Paris, 1988.

United Nations. Department of International Economic and SocialAffairs: Interrelation: resources, environment, population and development. Proceedings of a United Nations Symposium held at Stockholm from 6 to 10 August 1979. New York, 1980.

United Nations Environment Programme (UNEP): The environment situation and activities in the Asia-PacifK region in 1979. Bangkok, 1980.

Ward, Barbara and Rene Dubos: Only one earth. New York, W.W. Norton & Co. Inc., 1972.

Chapter 14

Framework for Environmental Education*

There are sufficient commonalities of environmental concerns in the ASEAN to justify a broad framework for all six countries. The discussions at the Environmental Education Con- ference in Malaysia brought out the following problems as common in the Southeast Asian region.

a. Population pressure in the cities and its consequences such as insufficient human settlement, conversion of agricultural land at the fringes of cities into human settlement areas, pollution, inadequate transportation, solid waste disposal, etc.

b. Health problems and inadequate medical services particularly in the rural areas.

c. Deforestation and the resulting flooding during the rainy season and water shortage during the warm season.

Children in the ASEAN have enough similarities of growth and development to ensure applicability of a unified EE framework. Cross-cultural studies in education have shown that children the world over go through the same stages of cognitive development.

Some environmental problems of one country are known to infringe and impact on adjacent countries. A unified approach by the ASEAN members to environmental problems as taught in their respective schools can be instrumental to closer and more harmonious relationships and better understanding among them.

EE in each member country is still in the formative stage. There is no more opportune time than now for a unified broad EE framework. The EE framework can provide direction to environmental education activities in the ASEAN.

We are hopeful that an EE framework that is sufficiently versatile to allow for diversities of perspectives and practices yet unified in purpose and major environmental understandings can be developed. What kind of ASEAN EE framework shall be developed?

First, let us define what a broad framework is. An examination of the EE global framework developed in Belgrade, the EE framework by Brennan and the Israeli EE project lead us to the following statements on what functions or services our ASEAN EE framework can perform.

l An educational plan; in short, a curriculum with an extensive scope.

* Prepared by Dr. Leticia P. Cartes, Curriculum Research Coordinator and Science Education Specialist, UP-ISMED. Philippines.


l A position paper stating the beliefs and ideas a group stands for, and a proposition specifying in clear terms what the group proposes to do to spread these beliefs and ideas on EE.

. A model for national, zonal, or school adoption and adaptation to suit particular environments and needs.

l An integrative mechanism for educational activities concerning the environment in the ASEAN.

Decisions need to be made on the following:

SCOPE

a.

b.

C.

Formal education versus nonformal: Should the ASEAN EE framework be so constructed as to confine EE activities to the formal education system or should it make efforts to include the non-formal education system and establish linkages with mass media and non-governmental organizations.

Target audience: Should the ASEAN EE framework consider only the secondary school (and also the out-of-school adolescents, depending on the decision made on a.) or should it also plan for the other school levels such as elementary and tertiary and their corresponding out-of-school age groups. Alternatively, should it target the general populace?

Should the EE thrusts be confined to Science only or to any course that lends itself well to EE infusion?

STRATEGY

a. Should the strategy for implementation be that of the multidisciplinary (infusion) approach or the interdisciplinary approach?

b. What instructional techniques should be recommended for use in EE-oriented classes?

c. What competencies should be emphasized for development at different age levels?

What are the possible components of an ASEAN EE framework? The participants may consider the following for inclusion and subsequent development:

l Description of the environmental conditions in the ASEAN to serve as a rationale for the EE framework.

l Statement of philosophy consisting of the beliefs concerning man’s relationship with the environment and an enhanced relationship and an enhanced quality of the environment.

l Goals and objectives of EE in the ASEAN and the competencies that should be developed in the target audience.

l Main topics or concepts to recommend for certain grade levels or age groups.

l Role of formal education system and, if included, also those of non-formal systems (mass media, NGOs, other government agencies).

Framework for Environmental Education 173

l Strategies for developing and making EE materials (print and make available to agencies and institutions, particularly schools, involved in environmental education activities).

l Strategies for developing competencies of EE personnel (e.g. teachers, supervisors, out-of-school youth coordinators and leaders, curriculum writers, etc.)

The ASEAN Philosophy of EE

The ASEAN, in pursuance of the initiatives made by its various committees - the Com- mittee on Science and Technology (COST), the Committee on Social Development (COSD), and the Chamber of Commerce and Industry (CCI), among others - is now surging toward economic growth, technological progress, and industrial development in efforts to eradicate poverty, raise the level and quality of education, and prevent the exploitation and domination of one group of people by another, or of one nation by another nation. This growth and development is not without environmental cost. Signs of this stress are already evident: deforestation, shortages of certain natural resources such as water and energy, crowding in urban areas, increasing incidence of environmentally caused health problems, to name a few. The answer to these rising problems is environmental management by way of conservation and sustainable development.

Environmental education is one potent environmental management strategy. There is no better time than now to build the framework of a truly ASEAN environmental education programme that will develop in each member nation the competence to manage its own environment for its own optimal development without losing sight of its own socio-cultural and religious heritage, yet looking forward to cooperation, mutual trust, and harmonious relationships with other member nations.

It is envisioned that the ASEAN EE programme will develop in the peoples of the region a sensitivity and concern for the environment, foster environmental values and attitudes, generate knowledge and better understanding of environmental phenomena, develop skills in solving environmental problems, and spur people to action that will’enhance the quality of life for the present and future generations. It should be able to instil1 in everyone a sense of responsibility to take care of and work for the improvement of the environment.

Goals of ASEAN Cooperation in EE

1. To formulate an ASEAN Environmental Education programme that will develop in the region’s populace an understanding of environmental phenomena and processes, skills and values needed to ensure an ecologically harmonious, sustainable development and productivity of the environment.

2. To share new scientific and technological knowledge to enhance the quality of the environment in the ASEAN region.

3. To exchange new educational approaches, techniques, and teaching devices appropriate to environmental education in order to advance the frontiers 01 environmental education in the ASEAN region.


Objectives of the ASEAN EE Programme

The EE Programme is designed to enable students to:

1. Acquire basic understanding of the interrelationships of components and factors of the environment and the processes that occur in it.

2. Develop desirable values and attitudes, especially concern and responsibility toward the conservation and enhancement of the environment.

3. Acquire and refine skills in identifying, assessing, and solving environmental problems.

4. Develop a sense of urgency in responding to environmental issues and problems and taking action toward their solution.

Content of the Framework

Basic Ecological Concepts

1.

2.

3.

4.

5.

6.

Human is an important part of the ecosystem. He/ she must understand how the components of the ecosystem interact and depend on each other.

Nature has its own way of maintaining environmental equilibrium.

Human’s culture including his technological activities create imbalance in the ecosystem.

To restore balance in nature, human has to reassess his attitude, behavioural patterns and ethical standards.

Some currently accepted values are in conflict with existing responsible environmental actions/campaigns.

Individuals, government and non-government agencies, national and international, must work for sustainable development to reduce depletion of resources and reduce environmental problems.

Energy

Energy Flow in the Biosphere

1. Energy is transferred from producers to primary consumers, then to secondary consumers in a food web.

2. The sun is the primary source of energy that supports life on earth.

3. Plants convert solar energy to chemical energy.

4. The shorter the chain, the less energy is wasted.

5. Toxic substances can be transported through the food chain and eventually reach man.

6. Safety measures in the use of pesticides, insecticides, and herbicides, and the proper disposal of household and industrial waste and other toxicsubstances should be looked into.


7. Energy cannot be created nor destroyed but it can be transformed from one form to another.

Energy Utilization

1. Energy shortage causes various socio-economic and political problems.

2. Countries need energy for development and progress.

3. Energy must be used wisely used (at home, in commerce, and in industry).

4. In the extraction and use of energy, pollution of the environment may occur.

5. More research should be done to reduce energy costs and to find alternative and indigenous sources of energy such as biogas, biomass, solar, wind, geothermal, and energy from waves.

Pollution

1.

2.

3.

4.

5.

6.

7.

8.

Pollution refers to adverse changes in the environment which affect biotic and abiotic components.

Pollution is a problem associated with development activities, and may be the price paid for progress.

The main channels of global pollution are air and water.

Pollution results in damage to vegetation, animal lives, human lives and man’s proper-

ty-

Different pollutants come from a variety of sources.

The accumulation and dispersal of pollutants are affected by meteorological conditions as well as socio-economic factors.

Indiscriminate use and mismanagement of water resources due to human’s selfish motives have resulted in global water pollution.

Pollution control requires multi-sectoral participation. The participation/- action of each individual increases the probability of success of any pollution control programme.

Population

1. Population growth is self-regulating. Regulation is determined by the carrying capacity of an ecosystem.

2. Human can raise the carrying capacity of the environment by applying science and technology principles only up to a certain level.

3. Technological activities have an impact on the population of human and non-human species.

4. Human has developed techniques to alter genetic composition.

5. Population of the world is increasing at an alarming rate.

6. Population growth is influenced by physical, biological and socio-cultural factors.


7. Population density is generally higher in developing and underdeveloped countries then in developed countries.

8. Overpopulation brings about environmental and socio-economic problems as it increases the demand on the resource base.

9. The need for population control is dictated by the present world population situation and the carrying capacity of the environment.

10. All living organisms are interdependent.

11. Current value systems need to be reassessed.

12. Population growth can be controlled naturally or by artificial means. Population control depends on well defined policies and regulatory measures.

13. Cities represent a highly dense ecosystem.

14. The continuous migrationof rural people to urbancommunities (urbanization) creates environmental problems. There is an urgent need to plan measures to improve the quality of life of rural people.

15. Urban communities have a greater demand for the basic human needs such as food, water, air, clothing, housing, health services and transportation services, and education.

16. Population problems can be reduced through a multi-sectoral approach.

Basic Needs

1. To live we need air, water and food.

2. We need to take in oxygen from the air.

3. Oxygen is released by green plants during the process of photosynthesis.

4. Planting greenery helps to purify the air.

5. Green plants need water and energy, among other factors, in order to manufacture food.

6. The natural sources of fresh water on earth are surface water and underground water.

7. Surface water such as in rivers and lakes originates from watershed forests.

8. Underground water is tapped by the construction of wells.

9. Dams are built to store water for use when needed.

10. Water needs to be purified before it is taken by the human body.

11. In addition to water, human obtains other sources of food through agricultural practices.

12. To increase the yield of food, human uses fertilizers and pesticides.

13. The misuse of fertilizers and pesticides affects human’s health and degrades the environment.


14. Some kinds of food have to be processed and preserved before they are transported to the consumers.

15. The preservation of food through the use of chemical additives might be hazardous to health.

16. To live clean and healthy, human should preserve the quality of air, water and food.

Health and Environment

1. Health hazards caused by noise, air, water, solid and toxic waste pollution leads to:

l Impairment of hearing;

l Formation of smoke and smog which cause respiratory problems;

l Food poisoning and diseases due to contaminated food;

l Formation of acid rain which affects cultivation of food crops;

l Contamination of water supply due to dumping of industrial toxic wastes.

2. Health hazards caused by overpopulation include:

l Poor sanitation and ventilation due to bad housing conditions;

l Poverty and malnutrition.

3. Deforestation leads to a reduction in the supply of herbal medicines and thereby affects medical research.

Natural Resources

A. Forest Resources

1. Forest resources are useful in many ways. They:

l Are sources of fuel, building materials, medicine

l Are habitats of wildlife

l Help regulate CO2/02 in air

l Provide watersheds

l Help maintain rainfall

2. The destruction of tropical forests to obtain fuel and building materials and to utilize the land for growing crops and other developments such as building industries, houses, roads, dam, etc. would cause:

0 Soil erosion

l Imbalance of COti in the air

l Reduction of rainfall

l Flooding

l Extinction of species (wildlife)

l Displacement of inhabitants living in the surrounding affected areas

-_-

Part /I - Pedagogical Aspects 178

3. The clearing of mangrove forests for fuel, building materials and commercial fresh water farming will cause the destruction of the ecosystem, the inundation of the shoreline/inland area and the reduction of food supply.

4. Planting of trees can help:

. Prevent soil erosion

. Regulate COti in the air

l Cool the surrounding area

B. Water Resources

1. There are several sources of water:

. Lakes

l Rivers

. Ponds

l Reservoirs

2. Water is essential to sustain life.

3. Water is used in:

l Agriculture

. Industries

. Generating hydroelectric power

l Domestic and recreational activities

4. The demand for usable water is increasing due to the rapid growth of population and industrial development.

5. The quantity and quality of water resources are affected by the way human uses water.

6. Water resources must be managed intelligently through:

l Reducing water use;

. Maintaining and preserving watershed;

0 Controlling water pollution;

l Recycling water.

C. Marine Resources

1. Marine resources constitute one of the world’s principal renewable resources.

2. They are the only natural resource based on the productivity of the ecosystem.

3. They include marine fishes and other organisms in the seas and oceans, and the estuarine or coastal fishes and organisms.


Marine Fishery

4. There is a direct and an indirect utilization of the marine ecosystem.

. The direct use is the harvesting of fish, marine mammals and other organisms (Fishery).

l The indirect use is the oceans’ role in determining climate, producing 02 and diluting wastes (Ocean).

5. There are conflicts between fishery use and ocean use of the marine ecosystem.

l They exist mainly in the areas ofi

- Transportation via ships, boats, tankers and supertankers;

- Mining and dredging of the seas;

- Waste disposal and pollution;

- Oil exploration and production.

l Overexploitation of marine fishes and mammals leads to depletion of (food) resources. Economic losses occur and fishermen (and consumers) face food demand-supply problems.

l Industrial pollution causes health hazards. Examples like Minimata and Itai-itai in Japan and red tides almost everywhere are causes for concern. Diseases and sometimes death do occur.

l Nations impose 200 mile limits to conserve their own marine resources. This has led to disagreements or dispute among nations over national boundaries.

Estuarine Resources

6. Where the salty seawater meets the fresh river-water abundant plant and animal organisms thrive --- Estuarine resources.

7. Rivers supply rapid replenishment of plant nutrients to the estuarine ecosystem.

8. Fstuarine resources may be divided into mangrove forests and aquatic inhabitants.

9. Mangrove Forests.

10. Aquatic Organisms:

l Common aquatic organisms in an estuarine ecosystem are fish, crustaceans and molluscs.

l These are part of the food chains of the estuarine ecosystem.

l Nutrients come from the estuarine waters themselves.

11. Problems in estuarine areas include the following:

l Depletion of mangrove trees/forests;

0 Overexploitation of estuarine resources;

. Pollution from up-river or pollution from the sea are washed up during high tides;


l Use of estuarine areas for drainage and development due to pressures from an expanding population nearby.

D. Wildlife Resources

1. Wildlife is important for maintaining the balance of ecosystems and the preservation of our cultural heritage and as a source of valuable information for scientific studies.

2. Conservation of wildlife, especially the endangered species, has ecological, aesthetic, socio-cultural and ethical implications.

3. Endangered wildlife species can be conserved through proper management of their habitats and adequate control mechanisms.

4. Wildlife sanctuaries are oftentimes destroyed by indiscriminate destruction of forests through logging, burning and poor agricultural practices.

E. Soil Resources

1. Soil, usually taken for granted, is a natural resource, the most important function of which is to support plant life.

2. The ability of the soil to support the growth and development of plants depends on soil condition, the quality of the plants and climatic conditions.

3. Aside from food taken from plants grown in soil, plants provide life-sustaining oxygen, forest products like wood, natural fibres and native fuels.

4. Soil is made up of inorganic substances from parent rocks which have undergone several physical and chemical changes, together with organic substances from decomposed plant and animal remains.

5. Fertile soil lost through thoughtlessness of people and through erosion resulting from clearing of forests and mining activities could take centuries to be retrieved.

Corrective Measures

1. All types of pollution may be reduced through:

0 Proper enforcement of laws;

l Increase public awareness of environmental issues through information campaigns and mass media;

l Public participation in environmental management activities.

2. Overpopulation can be controlled by:

0 proper family planning;

l proper housing and town planning.

3. Deforestation can be controlled by:

l Proper enforcement of forestry and laws;

l Recycling of wood products;

l Optimizing land use by integrated farming method.

Chapter 15

Planning and Developing Curricula on EE*

There are two models of EE curriculum suggested by Hungerford and Peyton (Unesco EE Series 22). One model is called the interdisciplinary (single subject) model. This relies primarily on all disciplines and relevant components of many disciplines are drawn upon to create a distinct EE unit, course, or module. The other model is called multidisciplinary because EE components are infused into other established disciplines where appropriate. Whichever model we are going to adapt, several questions have to be answered.

In what context should Environmental Education be conducted?

The Belgrade Charter includes the following six EE objectives.

1. Awareness - to help individuals and social groups acquire an awareness of and sensitivity to the total environment and its associated problems.

2. Knowledge - to help individuals and social groups acquire basic understanding of the total environment, its associated problems and humanity’s critically responsible presence and role in it.

3. Attitude - to help individuals and social groups acquire social values, strong feelings of concern for the environment and the motivation to actively participate in its protection and improvement.

4. Skills - to help individuals and social groups acquire the knowledge and skills for solving environmental problems.

5. Evaluation Ability - to help individuals and social groups evaluate environmental measures and educational programmes in terms of ecological, political, economic, social, aesthetic and educational factors.

6. Participation - to help individuals and social groups develop a sense of responsibility . and urgency regarding environmental problems to ensure appropriate action for

solving these problems.

The first two objectives are concerned with education about the environment, that is, with providing cognitive understanding and the development of skills to obtain this understanding.

* Prepared by Dr. Merle C. Tan, Science Education Specialist and Chairman, Environmental Science Education Workgroup, UP-ISMED, Philippines.


The four remaining objectives address the education for the environment concern, that is they are directed towards environmental preservation and improvement.

What should be our model for EE?

Arguments for and against the two models of curriculum discussed above are on pp. 14-15 of EES No. 22. Based on country reports, however, it is evident that the model used in the six ASEAN countries is the infusion model. Can we change this? Why or why not? What other models can be used?

What should be the course structure?

The broad framework that was prepared earlier lists conceptual statements based on six themes. Which of these concepts can be taught at what level of education? What will come first - Population or Pollution? Energy Issues or Basic Needs? Can the conceptual statements be restructured so that statements relating to management are put together in one section, and environmental problems in another section, and so on? Why or why not?

What should be the mode of integration?

Should it be the science first approach, that is focused on science content and integrating environmental problems or issues whenever possible? Or, should it be the application-first approach focusing on an issue or problem and developing the relevant science content?

Concept Mapping as a Curriculum Development Strategy

Concept mapping is basically an instructional technique to facilitate meaningful learning. Its effectiveness however, has been found in curriculum development.

A concept map is a device for representing the conceptual structure of a discipline or part of a discipline. It is represented as a diagram showing the relationship between concepts. The nature of the relationship between concepts is stated on lines drawn between two appropriate concepts.

Asimple concept map consistsof two concepts. (Aconcept may be asituation or properties of things designated by a label or symbol.) They can be linked by logical connectives. See examples below.

Example 1.

is made up of

I I

Example 2.

undergoes .:

Planning and Developing Curricula on EE 185

The words in the boxes are concepts while the word or group of words on the line constitutes a proposi-

tion that gives meaning to the concepts.

Concept Grouping

Point Grouping - a number of single concepts emanate from one concept.

Example 3.

USED WISELY

I has to be

/ TRANSFORMED

I

The concepts emanating from the main concept Energy are not arranged in a hierarchical order.

Open Grouping - three or more concepts are linked in a single chain. In this grouping, more general concepts are found at the top while the specific concepts are found at the lower end of the map.

Example 4.

I is the study of the interaction between

t

Living Things

4 1 in

plants 1-

animals

are

/ I

are -

producers consumers __-~-


Closed Grouping - concepts form a closed group.

The example in open grouping can become a closed group by connecting a concept that would relate producers and consumers.

Example 5.

The more extensive branching of concepts there are (i.e. the more specific concepts connected to general concepts)the better the understanding of related concepts. Note that the propositions written on the line joining any two concepts may be simple English words or phrases or made up of scientific propositions. The more scientific propositions used, the better the understanding of the concepts. In Example 4, the proposition “is the study of the interaction between” is considered a scientific proposition.

Concept maps for the same topic may vary depending on who makes the map and the focus of the discussion. For example, the topic Alcohol may be developed from three perspectives: as an energy alternative; as a pollution issue; and as a health problem.

Strategy for Teaching Construction of Concept Maps

1. Give stacks of cards, each card bearing a term which is thought to be integral to the topic. Use few concepts at the start.

2. Ask participants to place the cards on a large sheet of paper so that related terms are done together.

3. Ask participants to draw lines between related terms and to write on the lines the nature of the relationship.

Planning and Developing Curricula on EE 187

Practicum: Concept Mapping and Textbook Analysis

Al.

A-2.

B-1.

B.2.

Divide yourselves into 5 groups. Prepare a concept map based on the given set of related concepts on Population.

Present your output in the class.

Group yourselves by country.

Analyze a unit of your science textbook or syllabus for secondary schools and prepare a table with the following columns. Answer the questions that follow.

Main Topic: ! I

Conceptual Statement

(Context) Level at which EE

Education Orientation concept is taught

About For Local International

Q. In what context are your EE materials focused?

Q. How would you translate science content about into education for the environment? Give a specific example.

Q. What are the criteria for including particular environmental enhancement concepts into specific levels of education?

B-3.

B.4.

Choose one concept and prepare a map to show related concepts.

Present your output in the class. Be able to discuss the advantages of the concept map you prepared for instructional materials development. Include values that can be taught when developing the concepts.

Chapter 16

The Role of Values Education in EE*

As I contemplate the raison d’etre of environmental education, memories of my early childhood keep surging back. As a little girl, my family travelled a lot, and I recall that I was often fascinated with the beauty and the grandeur of nature whenever we visited the countryside.

I remember the vast verdant fields and the emerald mountains canopied with a clear, azure sky, especially during summer. I could discern the fish swimming away from us as we waded in the brooks and rivers. As .we motored by woody roadsides, we could hear the birds chirp as they hopped through the foliage which was studded here and there with wild ferns and orchids. We enjoyed wading in the sea and gazing at the corals of lovely hues among which fish of varied colours wove in and out. We watched the fishermen bring in the day’s rich catch and marvelled at the wealth of marine life the sea could sustain.

Alas! Such God-given gifts are on the wane today. I am saddened when I see brown, balding mountains when I travel to the countryside. Now the cascading waterfalls that frothed and splashed in the sun during my childhood years are mere tiny rivulets rushing down the mountains. The brooks and creeks which were our favourite haunts have dried up, and the rivers and seas which were once clear and teeming with fish are now murky and dirty with flotsam and jetsam. Sometimes the fish from the sea becomes toxic when hit by red tide.

Everywhere in the world today, such environmental degradation is escalating. The air, land and water are increasingly becoming polluted. In some cities or large concentrations of population, the sky is no longer as clear on a summer day as it used to be because of smog, and the atmosphere is becoming warmer and warmer because of the increase in its carbon dioxide content. Marine life is ebbing where it used to be abundant and robust because of toxic wastes dumped into the sea. Cities, towns and villages suffer floods because of improper garbage disposal and failure to replant where mountain trees have been felled.

There is much serious concern about the thinning out of the ozone layer of the earth and the greenhouse effect caused by too much toxic waste in the atmosphere which threatens not only the tranquility of our existence but our health and lives as well. I do not wish to sound like the prophet of doom, but I must state that the world is virtually sitting on an environmental time bomb that is ticking away without the consciousness of many of us, and unless we diffuse it soonest, our life on planet earth will be imperilled, or even worse, snuffed out simply because

* Paper by Dr. Minda C. Sutaria, Consultant to INNOTECH and former Deputy Director of the Department of Education, Culture and Sports, Philippines.


of our lack of concern for the common good and the absence of a sense of responsibility for sustaining a balanced ecosystem.

Our endlessly enlarging environment, which has been reformed and recreated by human through science and technology, has at the same time become a poisonous object which we must detoxify and fortify against life-destroying elements, if we wish to dignify life in it for all humankind. In our quest for a better quality of life, we have exploited our resources in wanton disregard for the dangerous consequences that imperil life in the future.

Every human being has the right to decent life, but today there are elements in our environment that tend to militate against the attainment and enjoyment of such a life. The exacerbation of the pollution of the environment can cause untold misery, unhappiness and suffering to human beings. If we are to aspire to a better quality of life - one which will ensure freedom from want, from disease and from fear itself, then we must all join hands to stem the increasing toxification of this earth. While we aspire for the good life, we should not sacritice the future of the generations to come.

There must be concerted and committed efforts to put a stop to the pollution of our land, water and air and to adopt actions which shall help forestall further pollution of this earth. This cannot be achieved by mere fiat nor admonition nor rhetoric alone. We have laws against dynamite fishing, that prohibit the destruction of forests, that require replanting of trees in logging concessions, that outlaw smoke-belchingvehicles, that require proper disposal of waste, and other legislation supportive of our fight against pollution, but these are beingviolated every day and, tragically, the irresponsible violators go scat free and thus are encouraged to continue violating them. Meanwhile, the environmental time bomb continues to tick, the violators, ever oblivious that they are helping to bring it closer and closer to explosion, carry on with their contemptible deeds.

What we need in order to defuse this environmental time bomb is immediate concerted action of all the people to detoxify the environment, but such needed action will come only if we reorient the citizenry’s values, i.e., imbue them with proper attitudes and values, specifically those that will lead to a greater concern for preserving balance in the ecosystem, besides teaching them how to save the environment from further degradation.

This is where values development can play a central role in environmental education. The desire to help preserve the balance in the ecosystem specifically, to contribute to the detoxifica- tion of the environment, and to help make it a more healthful and progressive place to live in springs from a strong sense of social responsibility.

Let me share with you a values development approach to environmental education which we in the Philippines are starting to adopt as a result of successful experience in population education and drug education. This has been buoyed by the launching of a nationwide values education programme at all levels. The approach is anchored in the belief that behaviour oriented towards environmental protection stems from an individual’s attitudes and values.

One of the five objectives of our values education programme is to develop Filipinos who are social beings with a sense of responsibility for their community and environment.

There are two among the seven core values in the Philippine values education framework which are inextricably linked with environmental education, namely, harmony with nature and social responsibility. In the values education framework, each core value is ramified into particular related values, thus cleanliness, orderliness and beauty are linked with the core value

The Roles of Value Education in EE 791

“harmony with nature”. Similarly, common good and concern for others, among other values, are subsumed under “social responsibility”.

Values development is achieved through integration in the different subject areas as well as through a separate subject. In the elementary grades, it is integrated in all the subjects of the curriculum while in the secondary school it is taught as a separate subject as well as integrated in all areas of the curriculum. At the tertiary level, specific subjects are utilized as vehicles for values development except in the teacher education curriculum for secondary school teachers where it is offered as a separate course.

The approach to values development is eclectic, that is, it employs specific strategies under the umbrella of the experiential approach, such as value inculcation, value clarification, moral development, value analysis, values modification and action learning.

In environmental education, the values development strategies that will yield the best results are those which emphasize the provision of opportunities for learners to act on their values. The assumption here is that values education is not confined to cognitive learning which serves as the basis for the development of values. A value is not developed unless it manifests itself. Experiential learning is not confined to the classroom but extends to the home and community. Thus, it has great potential for developing values that relate to environmental preservation and development.

In environmental education, the emphasis should be on developing the values of social responsibility, concern for others and harmony with nature. Action which will lead to the development and reinforcement of these values should stem from a problem-solving situation focusing on an environment-related issue. An understanding of the problem or issue should lead the students to take a position which should propel them to decide whether or not to act, and then to plan strategies for action steps should they decide to act. Students should later be led to implement strategies for action, and then reflect on their action and consider the next steps.

Action learning as a strategy is potentially effective in the development of the values supportive of environmental preservation and protection because of its built-in opportunities for activities calculated to offset the growing problem of environmental degradation.

The target values in action learning could well be social responsibility and concern for others as well as harmony with nature. For would not our bodies of water and land be cleaner and our air be purer if the citizenry had greater concern for the common good and a sense of social responsibility as well as the values of orderliness, cleanliness and beauty which make for harmony with nature?

No amount of preaching to the citizenry about the perils of a polluted environment, the dangers of irresponsible disposal of wastes or deforestation and the benefits to mankind of greening the environment will make people act to forestall environmental degradation unless they are imbued with a deep concern for the common good, a sense of responsibility for maintaining a balanced and healthful ecosystem and a strong drive to achieve harmony with nature.

If environmental education is to defuse the environmental time bomb that has been ticking away and disturbing the serenity of life on planet earth, it needs to make values development its key component. This might yet be the element that can keep the environmental time bomb from exploding and smashing humankind into smithereens. The time to act is now, for tomorrow may be too late.

Chapter 17

Values Clarification in Environmental Education*

This chapter is about the teaching of values related to environmental issues, either in the regular science subjects in the secondary school or in a separate Values Education subject. A basic question is: can values be taught? Many educators agree that if values can be learned, then they can be taught.

Corollary questions are: how are values learned and, therefore, how should they be taught? Should they be taught directly or only by example? On this issue, the stand of many educators is that values should be taught both directly (in a separate Values Education class) and/or integrated with all the subjects.

In this chapter, the expression Values Education refers to a programme for developing values in students. Values Communication refers to the process of teaching values. This process involves various approaches, one of which is Values Integration.

Values integration, as an approach of communicating values, means teaching values in all the subjects as distinguished from the approach of teaching values in a separate Values Education class and Values Infusion which involves teaching values also within the school system but beyond the academic curriculum. In this paper, Values Integration is treated as a technique of teaching values as distinguished from another technique called Values Clarifica- tion.

Values Integration

This topic is not the focus of this chapter. It is placed here only to allow discussion of how values clarification differs from it. A teacher who plans to use this technique should do the following:

1. Identify the values relevant to the content and processes/activities involved in the subject.

2. Develop instructional materials and lesson plans with which those values can be taught most effectively.

* Prepared by Dr. Lilia M. Rabago, Chairman, Dept. of Science Teaching, College of Education, University of the Philippines, Diliman, Quezon City.


Like the other subjects in the curriculum, science is very rich in opportunities for teaching values to the students. This is especially true of the laboratory where students consciously or unconsciously learn values practically every minute of the period.

Among the values developed in the laboratory are the following:

l Carefulness - in planning and performing experiments as well as in handling equipment;

l Objectivity - in analyzing and interpreting experimental results;

e Perseverance - in performing tests that stubbornly yield undesired or unexpected results;

0 Patience - in waiting for results of experiments;

l Cleanliness - both on the laboratory table and in the storage room;

l Orderliness - in recording data as well as in storing equipment;

l Cooperation and willingness to work with others, and share materials;

l Honesty and accuracy in gathering and reporting data;

l Thrift - in using just the prescribed amount of reagents;

l Neatness in preparing reports and promptness in submitting them to the teacher.

The situation in the lecture period is not as simple for teaching values. As mentioned earlier, the teacher must think of the value or values most relevant to the topic at hand and then develop instructional materials which integrate the value(s) identified.

In values integration, the student activities are varied and are all directly related to the lesson as can be gleaned from the activities cited in the sample instructional material.

Values Clarification

Louis Rath, Merrill Harmin and Sidney Simon formulated a model to describe the processes an individual goes through in internalizing a value (also known as valuing). The three processes are:

l Choosi.ng - freely, from alternatives, after thoughtful consideration of the consequences of each alternative;

l Prizing - cherishing, being happy with the choice, willing to affirm the choice publicly;

l Acting - doing something about the choice, doing it repeatedly and consistently.

Values clarification is a technique which is directly based on the valuing model by Rath, Harmin and Simon. A teacher who plans to use this technique in his class should do the following:

1. Present the stimulus material to the class.

2. Let the students undertake a preliminary decision making when they go through this process:

a. The students recognize/identify the alternatives;

Values Clarification in Environmental Education 195

b. They consider the possible consequences of each alternative;

c. They choose the best alternative.

3. Have a group discussion .

d. The students justify/defend their choice (c above)

4. Give the students a chance to make a final decision on the issue

e. As a result of the group discussion, the student may change or reaffirm his stand on the issue.

For the success of this last step, it is important that the student is mentally and emotionally mature.

Notice how values clarification differs from values integration. In values integration, the teacher calls the student’s attention to a desirable value and shows the wisdom in possessing it. In values clarification, the teacher simply gives the student an opportunity to clarify his personal stand on an issue. Consequently, the teacher is not supposed to pass outright judgment on the “rightness” or “wrongness” of the student’s stand; it is his personal stand; the teacher simply wants to know what that stand is.

It is clear, therefore, that values clarification should not be used alone in teaching values but rather in combination with other techniques. It works on the assumption that the student has first been given sufficient information and has developed insights which can serve as bases or criteria for assessing the alternatives of an issue and subsequently making a stand. Otherwise the teacher cannot be sure of the value he is actually helping the students internalize through values clarification. To illustrate, imagine a situation where a group of families decide to get together and have a “pot luck” for lunch. They put all the food on the table -vegetables, fruits, meat dishes, candies, ice cream, soft drinks, and others. A mother now calls her four-year -old son and says, “Let’s have lunch! We have plenty of food on the table. What do you like to have for lunch?” What if the child says, “I like candies for lunch;” what would the mother do? Would she allow her son to have candies for lunch on the grounds that it is his choice and he has the right to choose the food he wants to eat and she would beviolating his human right if she refuses to let him have candy for lunch? Values clarification, therefore, is most helpful after using other values communication techniques, but not before.

Among the most commonly used strategies in values clarification are: opinion poll; ranking order; value continuum; choosing from alternatives and justifying the choice; role playing; drama/skit; and pictures without captions. Following are examples of the first four.

Part I! - Pedagogical Aspects 196

Opinion Poll

Below are possible measures to reduce pollution of our surroundings. Indicate your opinion by putting a check (/) in the proper columns.

TOTALLY PARTIALLY AGREE AGREE DISAGREE

1.

2.

Ban the use of plastic containers.

Use energy resources that cause least pollution (e.g., solar energy).

3. Encourage people to ride bicycles and paddled bancas instead of motor vehicles.

4. To dispose of solid waste, encourage landfill.

5. Reduce the tax paid by factories that have antipollution facilities.

6. Remove all smoke-belching vehicles from the road.

Rank Order

A and B below give two lists of problems of our environment. Which of the problems in each list do you consider urgent? Rank them by writing the number “1” beside the problem which you consider most urgent and “5” beside the least urgent.

A. smoke-belching vehicles

uncollected garbage

red tide

drinking water contaminated with harmful bacteria, amoeba, etc.

more and more squatters building shacks over waterways in the city.

B. rapid destruction of forests

disappearing wildlife

soil erosion

more frequent brown-outs

more and more farmlands converted into subdivisions

Values Clarification in Environmental Education 197

Value Continuum

Your position on the following issues can be anywhere within a 5-point scale. The extremes are described in each item. Indicate your position on the issue by encircling the corresponding letter on the scale.

A. On the use of insecticides

a b I I f_--

Conrad0 Delfin

Conrad0 refuses to use any insecticide. Delfin uses insecticides freely both on his farm and inside his house. Where are you between these two extremes?

B. On the use of detergents

a L -.- -~~-- m-bLpp-r-pp ppp4mm mmmmp-_-_;:

Julia Teresa

Julia is absolutely against the use of any detergent. She uses soap only. Teresa buys detergent in bulk. She uses it lavishly in washing clothes, kitchen utensils, etc. Where are you between these two extremes?

Choosing from Alternatives and Justifying the Choice

A. To improve or safeguard the quality of life of its citizens, which of the following problems should the government try to solve first? Justify your choice.

1. Poor condition of roads

2. Frequent brown-outs

3. Widespread illegal logging

4. Decreasing number of tourists visiting the country

5. Insufficient transportation facilities in urban centers

B. Considering the current state of our forest resources, the financial capability of our country and available needed manpower, which of the following is the best measure to conserve our forest resources? Just@ your choice.

1. Undertake tree planting projects.

2. Impose a total ban on logging for the next 25 years.

3. Employ more foresters to discourage people from engaging in illegal logging and illegal harvesting of secondary forest products.

4. Enlist the help of the military to strictly enforce existing forest laws.

5. Pass a law that will impose heavy penalties on violators of existing forest laws.

Role playing and drama/skits are similar in that both involve students performing on stage or in front of the class. In role playing a problem situation is presented; the students are given (or asked to choose from) different roles of people concerned with the problem, and they are


asked to react to the situation and recommend steps toward the solution of the problem. On the part of the student, this includes:

a. his perception of the problem

b. how he feels toward the situation

C. what he proposes to do to solve the problem

In the drama or skit, a number of students are asked to memorize a prepared dialogue. After the presentation, the students in the audience are asked questions such as: “Who among the actors do you identify yourself with? I’; “Do you agree with (so-and-so) in the play? Why or why not?” In other words, role playing has no script whereas drama has.

One of the most interesting values clarification strategies is simply known as “picture without caption.” The students are shown a picture without a caption. Then they are asked to write one or two short paragraphs about what they see in the picture and the idea it puts across.

1. Identify the environmental issue(s) you like to tackle.

2. Identify the appropriate values clarification strategy for the issue(s) you chose.

3. Prepare the instructional materials.

Chapter 18

Ethics and Social Responsibility: Guidelines for Science Teachers*

Initial Notes for the Science Teacher

Facts and Values

Ethics and social responsibility belong to the realm of values. Science, on the other hand, belongs to the realm of facts. Science deals with describing ‘how the world works’ while ethics deals with prescribing ‘how the world should work’ and ‘how the people should behave’. The shift from a descriptive to a prescriptive modality is not an easy one for the science teacher because he has been trained more to teach facts and less to preach values.

It takes effort for the science teacher to learn, improvise, develop and test methods for teaching ethics and social responsibility to the environment.

Learning Values Need Prior Skills and Attitudes

Evaluation and valuing are advanced educational objectives (see Tables 18.1 and 18.2). Before a student can learn how to evaluate and how to value, he must have learned many prior skills and attitudes. Teaching ethics and attitudes of social responsibility towards the environment requires a certain level of achievement and maturity on the part of the student. A student cannot appreciate ecologically-based values if he has not mastered basic ecological facts and principles. Therefore, the science teacher must pay attention to correct pedagogic sequence, and the science supervisor or curriculum planner must pay attention to correct curricular sequence.

Teaching Values or Teaching About Values?

Evaluation is a cognitive skill. It is making judgments on ideas, methods, or outcomes with reference to a standard, criterion, or value. Literally, ‘evaluation’ means ‘measuring the value’ of something. Valuing, on the other hand, belongs to the affective domain; it is holding on to certain beliefs, attitudes or convictions such that they are consistently reflected in one’s behaviour.

* Prepared by Dr. Serafin D. Talisayon of theAsian Centre, University of the Philippmes.


Table 18.1. Bloom’s taxonomy of educational objectives in the cognitive domain.

1.0 Knowledge

1.1 Knowledge of specifics

1.2 Knowledge of ways and means of dealing with specifics

1.3 Knowledge of the universals and abstractions in a field

2.0 Comprehension

2.1 Translation

2.2 Interpretation

2.3 Extrapolation

3.0 Application

4.0 Analysis

4.1 Analysis of elements

4.2 Analysis of relationships

4.3 Analysis of organizational principles

5.0 Synthesis

5.1 Production of a unique communication

5.2 Production of a plan or proposed set of operations

5.3 Derivation of a set of abstract relations

6.0 Evaluation

6.1 Judgments in terms of internal evidence

6.2 Judgments in terms of external evidence

Table 18.2. Bloom ‘s taxonomy of educational objectives in the affective domain

1.0 Receiving (Attending) 3.1 Acceptance of a value

1.1 Awareness 3.2 Preference for a value

1.2 Willingness to receive 3.3 Commitment

1.3 Controlled or selected attention 4.0 Organization

2.0 Responding 4.1 Conceptualization of a value

2.1 Acquiescence in responding 4.2 Organization of a value system

2.2 Willingness to respond 5.0 Characterization by a value complex

2.3 Satisfaction in response 5.1 Generalized set

3.0 Valuing 5.2 Characterization

Source: Bloom, Benjamin S., J. Thomas Hastings, and George F. Madaus. Handbook on Fonnarive and Sumnative Evaluation of Shtdettt Learning. New York: McGraw-Hill, 1971.

Guidelines for Science Teachers 207

Evaluation skills and valuing do not always occur together. A person may be able to evaluate something according to certain criteria or values, even though he does not believe in them. We describe such a person as having a conceptual grasp of the value, but he has not internalized the value in his personal system of beliefs and preferences.

In other words, a science teacher can succeed in teaching his students about environmental values, without succeeding in having them accept and practice those values. This danger exists because it is far easier to teach concepts and cognitive skills than to impart socially-desirable attitudes and values. Bloom, who first devised the taxonomy of cognitive and affective educational objectives, had observed the tendency for affective educational objectives to be slowly eroded in practice.

The Science teacher should ask himself or herself: are you teaching values to your students, or are you merely teaching about values?

The Teacher’s Own Values

Values are made visible through behaviour. The final test of commitment is consistency of action. Values determine decisions in the face of difficult choices. If the teacher possesses adequate knowlcdgc about the subject matter of ecology and the environment, but is not personally committed to ecologically-based and environmentally sound values, the student can sense the discrepancy. On the other hand, if the teacher possesses a strong conviction, he can easily ‘infect’ his students by force of example. In teaching biology or ecology, our private personal lives cannot be isolated from pressing social issues. Perhaps it is illusion to believe that there are such things as purely private acts. A family planning advocate once said that the ‘sex act is a private act with public consequences’. As a general rule in ecology, every act, no matter how private, will eventually generate public consequences. To be effective, therefore, the teacher has to practice what hc preaches.

Is Science Value-Free?

Science tells us how the world works. It can be used to predict physical and biological consequences of human actions. It can be used to achieve desired physical and biological outcomes, and to carry them out efficiently and economically. Science, in short, provides a good guide in answering questions of means. However, it cannot by itself answer questions of ends. Science can tell us how to make fire; it cannot tell us whether we should use fire to cook our food or to burn our neighbour’s house. Science can tell us how to start a nuclear reaction. But it is not science that can tell us whether to use atomic energy to power industry or to destroy millions of people in a few seconds. That choice has to be made and it is made based on other criteria, such as the will of the’majority in society, or guidelines provided by our religious faith.

Generally, science is value free. But generally too, science insinuates materialist values. How? Scientists limit themselves to what they can observe with their known senses using present means. As a result science and technology conduce to values that tend to be focused on the material, sensate world. The scientific method, as now understood and taught, conduces to logical positivist, atomistic (e.g.analytical and compartmental), quantitative, and basically impersonal ways of thinking. Present science cannot and does not say anything about those things that cannot be observed with the five senses. In this sense science as we know it today is not absolutely value free. If not disciplined to serve man and his nobler purposes, scicncc and


technology have the capacity to insinuate these materialist values despite the avowed objectivity of science and its methods.

Therefore, science teachers and science curriculum planners and developers should avoid those purely logical, impersonal, and socially-distant approaches to teaching science typical of many college-level science textbooks. At every opportunity, the science teacher should incul- cate the habit of viewing science from the standpoint of moral choice. They can do this through examples and applications, through studying historical mistakes, consequences of decisions, etc. For example, a science teacher committed to his calling cannot just teach nuclear physics without touching on the real threat of a global nuclear holocaust. When human survival is at stake, the science teacher should take a clear personal stand.

The general rule that science by itself is unable to answer questions of ends has very few exceptions. One exception is that branch of biology known as ecology. (Another is that branch of psychology called psychic research.) Most ecological principles which, like all scientific principles, are established from facts, carry prescriptive implications about how people should behave, how they should relate to each other in a society, and how they should act towards the environment. Ecology is the exception which allows us to move directly from facts to values. Thus, experts on ecology and the environment very often take definite ethical or moral positions about how society should relate to the environment. I have yet to see a professional ecologist who is unconcerned with the environment.

In teaching ecology, or biology in general, knowledge of facts and principles often leads an individual to be concerned about social issues. Ecological issues, facts and principles are educational vehicles for teaching wider social consciousness.

Bioethics

There is consequently a school of thought that a moral system can be derived from ecology, or biology in general. In other words, from biology can be derived bioethics. Bioethics, including environmental ethics, is the branch of ethics which deals with prescriptions and values resulting from our scientific knowledge of how the living environment works. Bioethics can surely assist in reversing the compartmentalistic, atomistic viewpoints that science generally insinuates and engenders in its students and practitioners.

In my judgment, science alone cannot be the basis even for bioethics because certain biological principles and applications have ambiguous, controversial, or maybe even socially undesirable implications. Examples arc competition and survival of the fittest, population control, surrogate motherhood, killing animals during experiments, artificial inseminationand eugenics.

If properly handled, the student of ecology and the environment can avoid these undesirable viewpoints and even achieve desirable reinforcement of socially desirable values. I said ‘properly handled’ because teaching values always involves judicious selection by the teacher and educational planner of the value to be taught.


Socially Desirable Environmental Values

Teaching Universally Valid Environmental Values.

What, then, are among the ecologically-based and environmentally sound values that science teachers could teach? How can we be certain that these are indeed socially desirable?

The most powerful rationale underlying a number of ecologically-based and environmentally sound values is the fundamental value (or even instinct) of human and social survival. Many ecological principles, if violated, threaten the survival or survivability of human communities. If so, then such ecologically-based and environmentally sound values are socially desirable, and this is indeed so in any culture.

Another fundamental value is preservation or improvement of human health and safety and its converse, the prevention of or liberation from pain and suffering. Corollary and supportive to this value is that of cleanliness - from the personal, family, and community standpoints.

In an opinion survey, water users were interviewed and asked to score the extent of undesirability of each of a number of undesirable environmental events affecting natural water bodies. The most undesirable events are those that pose risks to human life and limb, followed by risks to human health. Events that cause loss or damage to property, or economic loss, constitute the third-ranked category. These provide a strong and appealing rationale for greater social responsibility to the environment.

Unfortunately, events which only impair sources of human sustenance or life support systems are not perceived as equally undesirable. It appears that environmental harm is perceived as minor or remote. If lack of knowledge of ecological facts and principles contributes to this low perception, then this is where environmental education should come in. There must be a clear understanding of the concept of life support system, and a conceptual link between damage to a life support system and eventual harm to human communities. Thus, a remote and long-term risk becomes more visible and real to the student.

The job of teaching socially desirable values is easy if one is teaching ecology. However, the science teacher will have to exercise judgment in selecting which social values to emphasize on the basis of ecological facts and principles. Ecological principles which carry major moral implications for society are the following:

1. Interrelatedness of nature, that what happens in a part of the web of nature ultimately affects every other part, thereby leading to...

2. Systemic and holistic thinking; related to...

3. Global and internationalist values from the biophysical reality of the planetary biosphere, from the reality of the ecological web that ties every man to every man in this planet; and from the common threat to mankind posed by harming the biosphere (such as the greenhouse effect from carbon dioxide and deforestation, depleting of the ozone from use of fluorohydrocarbons, nuclear winter from global nuclear war, irretrievable loss of species, etc.);

4. Man is part of nature, hurting the natural ecosystem will eventually hurt man, and man is physically and biologically a part of the cycles of nature; thereby leading to...


5. Respect for nature and responsibility for its protection; and the reality that this responsibility, to be effective, must be socially shared rather than pursued by only a few individuals; that the more valid attitude is...

6. Attitudes of harmony and balance towards nature, rather than conquest and mastery;

7. Diversity of species leads to stability, or, monocultures lead to vulnerability;

8. Conservation, necessary because of the physical limits of nonrenewable and slowly- renewable natural resources and for the sake of future generations; preventing irretrievable loss of species; minimizing loss of natural capital (such as topsoil);

9. Maintenance of stability and productivity of an ecosystem; avoiding harvesting more than the sustainable yield; preserving natural cycles;

10. Minimizing stresses on the ecosystem such as dumping foreign substances (industrial wastes), disrupting natural flows of energy and biomaterials, simplifying food chains, reducing species diversity; destroying habitats; drastic changes in climate.

The main principle taught by ecology is interrelatedness of the web of life, and the main value taught is concern for everybody and everything in our planetary biosphere. Nobody is completely alone, isolated, or separate from the rest of man and nature, and the whole society eventually suffers if its members feel concerned only for themselves or their small group or their small corner of this planet.

Because the principles of ecology, like those of any science, are universal, the above environmental values are applicable to any culture or nation.

These moral principles can be reduced to specific and concrete terms to suit the level of comprehension of the student, such as:

l Minimize cutting trees (because trees produce oxygen for man, reduce atmospheric carbon dioxide, reduce erosion, provide habitats for small animals, etc.);

l Keep surroundings clean;

l Do not spray pesticides over leafy vegetables to be eaten by people;

. Avoid disposing harmful chemicals in natural bodies of water;

0 Return mother milkfish (sabalo) back to the ocean (because they will lay millions of eggs) ;

l Adopt contour plowing (in order to minimize soil erosion); etc.

Teaching Culture-Specific Values.

Certain science topics must be treated with care when taught without certain cultural or religious contexts. For example, using pigs and dogs as textbook examples or laboratory subjects is abhorrent in Muslim societies. Scientific study of the moon may also present some problems. Certain forms of birth control are taboo to conservative Catholics.

According to our definition, for as long as there is no clear consensus among members of a social group on a particular value, one cannot claim that value as socially desirable.


Different governments have different policies towards the environment. The duty of a science teacher, particularly one from the public schools, is to know the policy of his government regarding the environment. Generally, he should obey these policies because the teacher must offer the example of a good citizen. However, because government decision makers are not always knowledgeable about ecological facts and principles, and because they place greater importance on other political or economic objectives, cases may arise when the personal beliefs of an ecology teacher will differ from the environmental policies of his government. This happens very often. Another reason for differences of opinion is that not all ecological principles carry unambiguous moral implications.

Population control, which is euphemistically known as ‘family planning’,is an example of a controversial issue. Ecology teaches that population increases exponentially if there are no resource limits, but logistically if there are resource limits - which is often the case. Logistic growth takes a population to a maximum limit or ceiling known as the population carrying capacity. When population reaches this ceiling level, death rate due to starvation and crowding increases to match birth rate, and quality of life drops clown to practically zero. Is population control therefore a good thing? Some of the arguments for and against population control are as follows:

. It is a tool used by a rich minority to keep down the numbers of a poorer majority;

. One person from a developed country consumes and pollutes at a level equivalent to fifty or more persons from a developing country;

0 It is against the law of God;

. Growth of per capita income is retarded by population growth;

. Historic experience (phenomenon of ‘demographic transition’) shows that increasing economic growth is a better solution because high-income households typically want smaller family sizes; etc.

Another policy debate revolves around trade-offs between development and environmental protection. Often the pursuit of one is at the expense of the other. Thus, in most ASEAN countries, there are environmental lobby or pressure groups against big development projects, such as the Bakun hydroelectric power project in Sarawak, Malaysia; the Nam Choan hydroelectric power project in northern Thailand; and the Chico River Dam hydroelectric/irrigation project in northern Philippines.

In such casts, the Science teacher must be knowledgeable on the issue and make his own personal decision whether to follow the dictates of his (ecological) conscience or to follow the policy of his government, or to look for some middle ground.

Practicum

Formulating Specific Actions or Injunctions

Social responsibility and commitment are manifested and tested by performance of desirable actions and avoidance of undesirable actions. Such actions or injunctions can be formulated in the classroom, right after a discussion of an ecological concept or principle. Some actions or injunctions are applicable to the daily lives of the students; others are not.


. For example, after studying the topic of soil erosion, the following actions and injunctions can be formulated:

l Do not cultivate steep hillsides;

l Do plant trees and shrubs on steep hillsides; do not cut trees on steep hillsides;

l Do construct buttresses in extremely steep areas;

l Avoid excavations during the rainy season.

To make this classroom exercise more interesting, the students may be asked to invent slogans such as: “I help clean the air; do not cut me - a tree. ” “Ilogko tiog/&” (My river, my love). “Your smoke becomes my breath; smoke elsewhere. n “If you have no gir&iend, postpone having one; if you have a girlfn’end, postpone marriage; if you are married; postpone having children.” “Stop at four.” A contest can be started. Winning slogans can be painted on signboards and displayed in prominent places.

These classroom exercises have the effect of setting up norms of behaviour for young people to follow. These exercises may be started with primary-level students. Monitoring and follow-up can be designed by the teacher to find out how far student behaviour is in accordance with their classroom formulations.

Awareness, Understanding and Evaluation of Issues

At the cognitive level, understanding of a value can be taught and tested through evaluation of public issues related to the environment. Astudent is ready to learn evaluation if he possesses adequate knowledge and comprehension about an issue. This practicum is therefore appropriate to more mature students at the secondary level. The curricular sequence is: awareness, knowledge, comprehension, analysis-synthesis, and finally evaluation.

The science teacher may implement the following steps. Steps 1 to 4 are preparations the teacher must make before coming to class. Steps 5.1 to 5.6 are implemented with the students in the classroom.

Based on Environmental Impact Approach

1.

2.

3.

4.

Select an Issue. From a newspaper, select a public issue related to the environment. Do not select an issue which requires knowledge of a complex set of ecological facts and principles such as the greenhouse effect.

Isolate Environmental Impacts. List down all the environmental events (past or present) or possible consequences (future) involved in the issue. If two or more alternative courses of action are open, make a list for each alternative.

Identify Subsuming Concepts. List down the ecological and other scientific concepts and principles needed to understand the above environmental events and consequences.

If the students have sufficient knowledge to understand the environmental aspects of the issue, then use that issue. If not, look for another issue and repeat (1) to (3).

Identify Social Costs and Benefits. List the people who are benefiting (or will benefit), and the people who are suffering (or will suffer) losses, for each alternative course of action. If data is available, list in money units the costs and benefits.


5. Guide Students through the Process of Evaluation. The students, with the help of the teacher, should be able to:

l Describe the issue (knowledge of facts).

l Isolate the environmental impacts (comprehension and analysis).

l Explain each environmental impact (comprehension).

l Summarize the arguments for and against, including social costs and benefits (synthesis).

l Evaluate the action (synthesis and evaluation). The science teacher should first demonstrate this step, and gradually bring the students into the process. Be open to debate and disagreement. The students should feel free to take sides and argue each side, or to switch sides according to their judgement. The Science teacher must not show or give hints as to which side he is taking until after the whole learning process is finished. It may happen that a decision cannot be made by the class because some needed information is missing in Steps 5.2, 5.3, and 5.4. If this information is available then . . .

l Take a position on the issue. If information is incomplete, a position cannot be taken. In this case, the outcome of the evaluation is simple: an identification of additional information needed for evaluation and decision on the issue.

Community-Based Teaching and Learning

Action develops value, and value is tested by action. An avenue for teachingvalues is action such as the “community-based” teaching of science. The U. P. Institute for Science and Mathematics Education has been experimenting for some time now in “community-based” teaching of biology, chemistry and physics.

In this approach, the starting point is the community and its needs, not a science principle or lesson. The essence of the approach is two-fold: (1) selection, design and implementation of lessons most relevant to the needs and conditions of the community where the student lives; and (2) use of community resources and expertise in the teaching-learning process.

Local expertise is usually available in a rural community for science teaching. For example, students can learn science concepts by visiting a local baker, a carpenter, a farmer, an irrigation tender, an auto mechanic, or a radio-TV repair shop. The practical experiences and techniques employed by these people are largely unrecognized resources for teaching science and technol-

w-

Local means of livelihood, based on harvest or culture of natural resources (wood gathering, farming, fishing, seaweed gathering, etc.), can provide a starting point for teaching social responsibility towards the environment. Some possible issues in a rural coastal community are:

. Destruction of corals by dynamite-fishing;

. Slash-and-burn upland farming;

. Inadequate reforestation by logging companies;


. Overfishing of a river or lake;

. Hunting of endangered species;

l Using poison to catch freshwater fish;

. Lowering of water table from too many deep wells;

. River overflowing dikes;

. Drying up of streams kills crustaceans.

The detailed steps in this instructional methodology are described by other authors at the U.P. Institute for Science and Mathematics Education. This practicum is more complex and requires the science teacher to be specially trained. It is more appropriate at the secondary level. This practicum is superior because there are close linkages between principles, values and action that a student will experience.

Example of Evaluation of an Environmental Issue

Step 1. Select an Issue

The following news article appeared in The Manila Chronicle on July 10, 1989 (page 7):

Senate Asked to Curb Use of Asbestos.

SEN. Rene Saguisag has asked the Senate to consider passing legislation to ban or limit the use of asbestos, which has been reported to cause cancer.

In Resolution No. 557, Saguisag cited reports that even the United States, after a decade-long debate over the toxicity of asbestos, is set to ban nearly all uses of the widely-used material.

Sweden has banned its use since 1976, except as brake linings, which are 73 per cent asbestos.

Saguisag, who said he has fought attempts to lower the tariff on asbestos, asked the chamber to conduct an inquiry into the dangers posed by asbestos, used to line water pipes, for insulation, fireproofing and other uses in construction.

He expressed fears that “particularly vulnerable” are construction workers, demolition workers, and other asbestos

handlers and users and people living or working in buildings or areas with asbestos.

Reports have said the use and exposure to asbestos or asbestos emissions, after a number of years, causes lung cancer, asbestosis (fibrotic scarring of the lung tissue that results in pulmonary impairment and sometimes in death), and mesothelioma, a once rare form of cancer of the linings of the chest cavity or abdominal cavity.

Even a short exposure can be “fatal,” and “as little as half a day’s work exposure can start the disease cycle,” Saguisag quoted literature on the subject as saying.

The resolution states that Johns-Manvilles Corporation, America’s biggest asbestos maker, had gone bankrupt in August 1982, as it was the subiect of 500 suits a month about the substance’s health risks. In 1949, the firm’s medical director studied 708 asbestos workers and found 534 of them (more than 75 per cent) suffering from lung ailments.


Step 2. isolate Environmental Impacts

0 Impairment of lung tissue of people exposed to asbestos (asbestosis).

l Above average incidence of lung cancer among employees of asbestos companies (mesothelioma).

Step 3. Identify Subsuming Concepts

Fibre, inorganic fibre, asbestos, fireproof, common uses of asbestos, respiratory function, lung structure, cancer, fibrotic scarring.

If, in the judgment of the science teacher, students possess knowledge of the above concepts, or they can be explained in class based on what they already know, then proceed to Step 4.

Step 4. Identify Social Costs and Benefits

If a law is passed banning asbestos, the social benefits are:

l No further exposure to the population;

l Medical costs, loss of workdays due to sickness and death will be averted;

l Companies selling substitute materials will increase their sales and profits.

The social costs are:

l Companies dealing with asbestos will lose business;

l Their employees will lose jobs.

What other benefits and costs can you think of?

Step 5. Guide Students through the Process of Evaluation

Assuming the health risks have been medically proven, then steps must be taken to prevent disease and death. It is preferable that people lose profits and jobs rather than have many more people exposed to the risk. The law can provide compensation to affected manufacturing companies (which may be few), and assist in finding new jobs for their employees who will be displaced.

The teacher should not dominate the process of evaluation. Let students participate actively.

Step 6. Take a Position

The proposed law .should be passed by Congress.

Chapter 19

Community-based Environmental Education*

Perhaps no other area in scicncc education lends itself more naturally to community- oriented teaching than environmental education. Concern for the environment logically starts with one’s community. Furthermore, involvement of community residents is considered a revolutionary aspect in environmental management (Andaya 1989). The best advocates of an ecosystem are said to be community members whose livelihood depends on the ecosystem.

This paper adapts an approach used in high school physics teaching (Talisayon et. al. 1986) or in secondary school science teaching in general (Talisayon 1984). The approach utilizes community resources and addresses community needs and problems. The objectives of the approach are to widen the resource base of the teacher, highlight the real-life relevance of science. raise community consciousness in students and prepare them, as ordinary citizens or future scientists, for community work. Community-based science activities/projects have been done elsewhere in the world, for cxamplc, in Africa (Swift, 1983) and in the United States (Penick, 1984; Pcnick et. al., 1984).

A Model of the Approach

Community-based cnvironmcntal education in the school system may be viewed in three phases (Fig. 19.1):

Phase 1 - Assessing Community Needs/Resources and Identifying Environmental ProblcmsiIssucs;

Phase 2 - Relating Environmental Problems/Issues to the Science Curriculum;

Phase 3 - Designing and Implementing Environmental Activities/Projects.

It is important for students to participate actively in all phases of the approach.

The first step in Phase 1 is for the teacher to select (in consultation with the students) the community whcrc the environment will bc studied. This community is preferably the place where the school is located or a locality accessible to most students or nearest their homes. It is best to choose a community large enough to have adequate material and human resources but small enough to be invcstigatcd with minimum expense to the students.

* Prepared hy Dr. Viwcn M. ‘l’alsayon, Science Education Specialist and hsistant Ihrcctor, UP-ISMED, I~iliman, Q.C:., I’hilippincs.


PHASE SOME STRATEGIES

Assesing Community Needs/ Resource - Conduct interviews of key community and Identifying Environmental leaders Problems/ Issues

: I-

l Study community development plan

l Make an observation trip around the community

Relating Environment Problems/ Issues to the Science Curriculum

. Identify underlying science concepts/

l Determine entry point in the

Designing and Implementing l Invite/ interview resource persons from Environmental Activities/ Projects the community

I

- Hold field trips to community sites

l Locate related instructional materials

l Write new instructional materials

l Have activities/ projects that help protect the environment

Figure 19.1. A Model of community-based environmental education

Needs and resource assessment can be done by interviewing key community leaders, studying the community development plan if available, or taking an observation trip around the community. The students select the community leaders to be interviewed and formulate the interview questions under the guidance of the teacher. Some examples of interview questions for a community leader are:

1. What are the goals of the community?

2. What are the pressing problems of the community?

3. What is the community doing to help solve these problems?

4. Which of these problems can we, the students, help solve?

5. How can we, the students, help solve these problems?

Community-based Environmental Education 213

6. How can we, the students, help achieve the community goals?

7. What are the human and material resources of the communiy?

Some questions may need clarification, elaboration, or translation into the local dialect.

The students report the results of their interviews and observation trips to .the class. Problems met, reactions of community leaders and a summary of gathered data can be presented. From the list of community needs and resources, the teacher can assist the students in identifying environmental problems and issues.

In Phase 2, the identified environmental problems and issues are linked with the science curriculum at hand: combined/ integrated science; biology; chemistry or physics. If students have taken up the relevant science concepts they can cite the underlying science concepts of an environmental problem with the teacher’s assistance. If students have not studied the concepts involved, the teacher can refer to the list of environmental problems in the future when the appropriate concepts are discussed. It will be useful to post the list of environmental roles in the community in the classroom for easy reference.

Table 19.1 lists some science concepts involved in some environmental problems. Iden- tifying the underlying science concepts facilitates the determination of the entry point of the environmental problem/issue in the science curriculum.

Table 19.1. Examples of student projects/activities for- some environmental problems in the community

ENVIRONMENTAL PROBLEM IN THE COMMUNITY

PROJECT/ ACTIVITY SCIENCE CONCEPTS

Garbage disposal Survey households for disposal practices. Study local laws on garbage disposal.

decomposition biodegradable bacteria

Flood

Soil erosion

Stagnant pond of water

Noise from airport

Keep weekly record of elevation of rain gauge a river. streamflow Keep weekly record of rainfall. elevation Observe hourly elevation of river rain intensity after a storm or typhoon. contour or topographic map Draw a map of drainage channels, also showing elevation contour.

Measure sediment of a river. soil composition Estimate amount of soil lost in one split versus sand siltation sediment year. load

Dctcct presence of mosquito life cycle of mosquito larvae. Observe growth of mosquito larve. malaria

Mcasurc noise level during aircraft decibel takeoff. noise level

noise standard -

. . . - - - l . - c__ ^ - . - _- -1_---


Table 19. I. Examples of student projects/activities for some environmental problems in the community (cant ‘d)

ENVIRONMENTAL PROBLEM IN THE COMMUNITY

Smoke from factory

Smoke belching from vehicles

High population density High population growth rate

Littering

Polluted drinking water Polluted river Seawater intrusion in drinking water

PROJECT/ ACTIVITY

Observe height of smokestack, wind direction, smell, and relate to factory product

Report plate numbers of vehicles belching excessive smoke. Study local laws against smoke belching vehicles Compare rate of incidence of respiratory diseases between inner city and suburb.

Survey family sizes and births. Survey usage patterns of family planning. Survey in-migration last year.

Survey places with much litter and report to authorities Study local laws, if any, against littering.

Examine microorganisms under microscope. Measure concentration of E. coli bacteria. Measure amount of sediment after settling. Measure BOD (biological oxygen demand). Measure chloride concentration. Compare rates of incidence of gastrointestinal diseases in rainy and dry seasons.

SCIENCE CONCEPTS

particulates smoke plume diffusion mass movement wind

emphysema rate of incidents

type of respiratory diseases

birth rate population growth methods of family planning

air/ land/ water pollution

E. coli siltation BOD analysis chloride analysis etiology of gastro-intestinal disease:

The most challenging task for the teacher and students is the design of environmental projects/activities in Phase 3. Consultation with scientists, engineers, other resource persons in the community, and members of the community directly involved or affected in the project is important for the feasibility of the design. The project/activity must be one that can be done safely by students at minimum expense.

Examples of student projects/activities are shown in Table 19.1. Figure 19.1 indicates some strategies in designing and implementing environmental projects/activities. Projects/activities illustrating several science concepts and helping to protect the community environment are recommended.

Community-based Environmental Education 215

An example of a detailed write-up of an environmental activity for students, entitled Noise Pollution, is given in the Appendix. In designing environmental projects, the social, political, economic and cultural implications should be included in the discussion to make students aware of the complexity of a real-life problem.

Projects/activities may be carried out by the class as a whole or by groups of students during class hours and, if needed, outside school time. Before an activity/project is done, the teacher should have clearly discussed the procedure and emphasized.safety measures.

During the implementation phase, reactions of students and the community to the activity project are obtained, for example, through questionnaire, interview, and observation. Students’ comprehension may be evaluated by a paper and pencil test. The students’ output or results of the activity also serve as a measure of attainment of objectives of the activity.

These forms of feedback may be utilized to make changes in the activity design and procedure. The feedback is also useful in Phase 2 (Fig. 19.1) relating the science curriculum to another environmental problem/issue. The cycle is repeated as many times as appropriate and practical throughout the schoolycar.

A reassessment of community needs and resources may be needed for the next batch of students to expose them to assessment procedures, skills and problems, as well as to reflect any changes in community conditions.

Implementation Problems and Possible Solutions

Some difficulties in designing and carrying out the community activities and projects may be met as each phase is implemented. Implementation problems may vary with place, teacher, and students. As a preventive measure, here are some possible problems and solutions:

Luck of time for teacher and students. Teachers with a heavy workload and students with a tight schedule may find difficulty in finding time for community activities. Seeking the students’ assistance at every phase of the community-based approach will lighten the load of the teacher.

Some class hours need to be set aside for community activities and projects. Since the total number of hours for science is fixed, this will mean shortening the time for some topics or deleting some sub-topics or topics. Criteria for deciding which topics to delete or shorten are the students’ needs and interests and topics covered in an external examination.

Lack of cooperation from the community and resource persons. This may be avoided if the teacher or students have close linkages or association with the person concerned. For resource persons who arc relatively strangers, carefully explaining the purpose and good intentions of the project or activity may result in cooperation. They may cooperate if their assistance is sought only once or twice. Observing society’s rules on proper behaviour in dealing with rcsourcc persons may be necessary to obtain their cooperation.

Problems of discipline and safety for activities conducted outside the classroom or school. Student monitors or leaders can help enforce class discipline. Discussion of safety procedures before undertaking an activity is a great help. Ask suggestions from the students. Members of each group can look out for each other’s safety. Always ask beforehand for written permission from parents for students to go outside the school during class hours.

Additional Expense for Students. This can be minimized by designing activities that can be carried out near the school. Transportation expenses should be cut down unless ncccssary.


Tapping resource persons known to students and who have access to other needed resources may reduce expenses.

The problems of implementation have to be weighed carefully against the benefits and objectives of the community-based approach. The existence or magnitude of a problem will be realized only as one actually goes through community-based environmental education.

Concluding Remarks

An approach for community-based environmental education for secondary school students has been described. The approach requires the active participation of students in all phases. Close supervision by the teacher and consultation with resource persons and the community are necessary to ensure the safety of students, feasibility of the environmental project/activity, and its successful implementation.

Environmental education becomes more meaningful and immediately relevant to students ifdone in the context of their community. More importantly, students are given the opportunity, as early as in high school, to participate as members of the community in the long-term planning and protection of their environment.

References

Andaya, Armando. The Philippines in the Year 2000: Challenges in Environment. Paper read at the DOST-SE1 Symposium on Science Education in the Year 2000, Philippine Normal College, 12 July 1989.

Joel Koren and Bal Krishna. Using Community Resources in Teaching Physics, Unpublished Report on the Unesco Regional Workshop on the Training of Physics Teachers, Univer- sity of the Philippines, Institute for Science and Mathematics Education Development, Quezon City, Philippines, 18-28 November 1986.

Penick, John E., ed. Focus on Excellence: Earth Science. Vol. 3 No. 3. Washington, D.C.: National Science Teachers Association, 1984.

Richard Meinhard-Pellens, cd. Focus on Excellence: Science/Technology/Society. Vol. 1 No. 5: Washington, D.C. National Science Teachers Association, 1984.

Swift, Digby G. Physics for Rural Development. Chichester: John Wiley and Sons, 1983.

Talisayon, Vivien M. Enhancingthe Relevance of Science Teachingand Leanzingfor Community Needs and Development Concerns, Bulletin of the Unesco Regional Office for Education in Asia and the Pacific. Number 25, June 1984, pp. 469-481.

Teaching Physics for Philippine Development. Monograph No. 38, Quezon City: University of the Philippines, Institute for Science and Mathematics Education Development, 1986.

Chapter 20

Inquiry and Problem Solvjng*

Learning by inquiry has been part of the science education scene for the last 20 years. According to the dictionary, inquiry is a search for information, knowledge, or truth. Learning by inquiry is a process of asking questions and looking for answers to these questions, or of identifying/recognizing problems and seeking solutions to the problems. Thus, inquiry and problem solving are closely linked.

Inquiry involves defining and investigating problems, formulating hypotheses, designing experiments, gathering data, and drawing generalizations from gathered data leading to a possible solution to the problem. When a student is engaged in inquiry, he or she uses skills - intellectual, psychomotor, and affective - to gain a better understanding of things or events encountered in the environment. In other words, inquiry is a mind-on, hands-on, as well as a heart-on process.

Why teach by inquiry? Not because it is the trend. There is research evidence to show that students taught by inquiry perform significantly better on cognitive tasks involving critical thinking. Students may not have covered the whole curriculum; a problem that often confronts teachers. But rcscarch shows that these students, in effect, retain more. On the other hand, there is wider coverage of subject matter in the traditional classroom, but retention is lower. The subsequent discussion deals with a few demonstration activities on inquiry and problem solving.

Using the Newspaper as a Starting Point for a Science Lesson

The newspaper is a good source of current issues, concerns and problems that can bc the focus of investigation in the science classroom. You may refer to a newspaper article.

Questions to answer:

. What problems can be discussed/investigated in the classroom on the basis of the articlc?

. Think of as many questions as possible that can be raised in relation to these problems.

* Prepared by Dr. Lourdes I<. <‘bale, Science Education Specialist and Education Chairman, l-lemenrary Science Education Workgroup, IJI’ISMI~Il.

----_-- ._.. _-______

Watch ing a Film in the Context of Inquiry


Science teachers and science educators are in general agreement that hands-on investigations, laboratory activities and experiments are the mainstay of effective science teaching. However, there are other methods of inquiry, and film is one of them. What is important is for the film to be preceded by raising of questions by students who will then actively seek answers. Through these questions, watching the film becomes a purposeful activity.

The film used in the demonstration is entitled “Death of a River.” The opening scenario is a beautiful, “live” river from which the community derives many benefits - bountiful catches, clear and clean water for washing and bathing, a serene and lovely sight for the soul. But as a result of several developments in the community, e.g. establishment of new industries that dislodge wastewater into the river, and increased human population that utilizes the river as a cesspool for domestic waste there arc marked changes in the river. Fish kills occur and fishermen experience dwindling catches; the water is murky and dark; many parts of the once beautiful river have become an eyesore due to accumulated waste. In other words, the river is dying, if it is not already dead.

Possible questions that may be raised by students:

l Why is the film entitled “Death of a River ‘?” What does the phrase “death of a river” mean?

. What human activities can cause pollution of a river’?

. What arc the cffccts of pollution on the river?

. What arc some signs that water is polluted?

. What causes the death of fish in the river?

One film will not provide all the answers to the students’ questions. Therefore, a need for continuous search arises. Students can employ other methods of inquiry in their quest for answers. Some of these m&hods are reading, listening to a resource person, interviews, and doing investigatory activities and experiments.

Doing Experiments

The film shows that one of the materials which may have contributed to the death of fish is detergent. There is no certainty that detergent has a harmful effect on fish. How can one find out if detergent has an cffcct on fish? An activity likely to be suggested is the carrying out of an experiment.

The following materials have to be provided: fish such as guppies; dechlorinated water (or unpolluted pond water); glass jars; detcrgcnt dissolved in water; medicine dropper.

You may give the following instructions:

A. Design or plan your expcrimcnt. Discuss the plan among members of your group.

B. Carry out your plan.

C. Report your group’s observation and inference to the class.

The role of the teacher is to listen to the students and to observe them while doing A and B. For instance, in A it is important to have a control setup and anexperimcntal setup (or several

Inquiry and Problem Solving 219

of these setups). If the concept of having a control is not clear to students, the teacher may give guide questions like:

l What do you want to find out in this experiment? (Whether detergent has an effect on fish.)

l What should be present in your experimental setup? (Detergent.)

(Note: Some students may decide to have several experimental setups with varying amounts of detergent.)

l How can you be sure that your observed result is due to the detergent? (There must be a control setup, or a jar of water which does not contain detergent.)

l If you have no control, and there is a change in the behaviour of the fish, what can be the possible reasons for such behaviour? (Possibilities like presence of some kind of dissolved material in the water whether gas or liquid or solid, cannot be ruled out.) This will bring up the need for a control.

While students are doing B, the teacher must observe them and be ready to give assistance when he/she feels it is needed. Otherwise, the students should be left on their own, discussing among themselves, sharing ideas, and working in a cooperative manner.

You will notice that the procedure being suggested here for conducting experiments is quite different from the usual way experiments are presented in textbooks. Generally, all the steps are given to students, to the last detail. All that they have to do is follow the instructions and make careful observations. However, this methodology does not vary much from following a cookbook, with detailed directions on how to prepare a particular dish. But being tied down to a cookbook is not the best training for becoming a good cook because a good cook must be able to create and innovate. In the same way, being a problem solver means finding new solutions to new problems. If problem solving is one of our goals in teaching science we should involve our students in free inquiry, where they evolve problems and plan strategies for solving the problems. This training in becoming a problem solver should be provided after they have had experiences in guided discovery.

Continuing the Search

An initial activity may lead to other investigations. For example, students may be stimulated by the activity on fish and detergents as well as the film Death of a River to find out more about water pollution in their own setting. Questions that they may raise are:

l How polluted is the river in our community?

l What are the common pollutants in our river’!

l What major activities make the river dirty?

Students may decide, with the teacher’s encouragement, to carry out an action plan, e.g.

1. Campaign to stop pollution of the river.

2. Make a testimony before the proper agency regarding major pollutants of the river.

. . - . . . - - . - I _ . -


3. Mount an educational drive in the community against pollution of the river, including preparation of posters and organization of seminars utilising leading community leaders as resource persons.

Problem Solving in a Real-Life Situation: Analysis of a Case Study

Problem-solving has several elements:

l Identification of the problem;

l Gathering of relevant information about the problem including causes and effects;

l Formulation and evaluation of possible solutions;

l Developing a plan of effective action;

l Carrying out the plan.

These elements have been used as bases for a case study on the problem of improper garbage disposal. This is a serious environmental concern in the Philippines and many ASEAN countries.

References

Krulik, S. & J.A. Rudnick. 1989. Problem Solving: A handbook for senior high school teachers. Allyn and Bacon, Boston.

NSTA. 1984. Focus on Excellence: Earth Science (ed. J.E. Penick) 3(3). NSTA, Washington.

NSTA. 1984. Focus on Excellence: Science, Technology, Society (ed. J.E. Penick). l(5). NSTA, Washington.

Penick, J.E. 1982. Developing Creativity as a Result of Science Instruction: What Research Says to the Science Teacher. 4:42-5 1.

Society for College Science Teachers. 1989. Enhancing Critical Thinking in the Sciences (ed. L.W. Crow). Society for College Science Teachers. Washington, D.C.

Trowbridge, L.W. & R.W. Bybee. 1986. Becoming a Secondary School Teacher. 4th ed. Merill Publishing Co., Columbus.

Unesco. 1986. Innovations in Science and Technology Education. Vol. 1 (ed. David Layton). Unesco, Paris.

Chapter 21

Games and Simulation in EE*

Differentiating Games From Simulation

An educational game is an activity in which players use data and/or skills usually in a competitive situation. It is useful for presenting repetitive learning in novel ways. The situation in which the information and skills are used may not accurately reflect some aspect(s) of reality. Conversely, a simulation accurately reflects some parts of reality. Students involved in a simulation are manipulating a model or playing roles which assist them to develop an understanding of and a feeling for the reality being presented.

Assessing Activities

These questions will assist teachers in assessing the value of particular simulations and games.

1. Do the objectives of the activity conform to the objectives of the section of the course being studied?

2. Is the activity appropriate for the students?

3. Is the activity interesting?

4. Is the activity workable in a classroom situation?

5. Does the activity have a sound knowledge base?

6. What is the central problem presented in the activity?

7. What are the choices available to the participants?

8. What are the different moves or activities provided for the participants?

9. What are the rules of the activity?

10. How is the activity to be organized (in the classroom)?

11. What summary exercises conclude the activity?

* Discussion paper prepared by Dr. Merle C. ‘Tan, UP-ISMED, Philippines.

--_ - ^..-._ --.. -.__


12. How are they used: As introductory activities for a unit of work? Are they appropriate for use throughout the learning sequence or as generalizing and concluding activities?

Guidelines for Conducting Simulations in Classrooms

1. Do not overuse simulations. Just as the students may have become immune to the motivational benefit of overused audio visual presentations, they may reach the point when they will say, “Oh, no, not another simulation.”

2. Incorporate the simulation activity into the overall structure of a learning unit.

3. Do not emphasize winning. Encourage students to see their achievements within the context of the satisfier-optimizer continuum (These are degrees of winning.)

4. Avoid individual student activity whenever possible. Group work will minimize individual disappointments, foster group decision making, interaction and team activity.

5. Before starting the activity, ensure that students have had adequate experience with reality to appreciate the activity as a simulation. Ensure that students see the activity as part of an integrated unit, discuss the purpose of the simulation, itemize learning objectives to form an evaluation checklist, and keep all rules and directions to a minimum, especially at the start of the activity.

How to Start Designing Original Simulation

Stage 1

Ask the class to bring copies of the previous weeks/months local newspapers. Each class member should cut out five news items likely to have an impact on the quality of the environment in their area.

Display each item on the classroom wall. Ask students to vote on which five topics represent their majority concerns.

Stage 2

Divide the class into four equal groups, each of which will have to play one of four roles. (These roles may be assigned so they can research their roles.)

a.

b.

Conservation (Environmentalist Groups)

These community members wish to preserve their environment as it stands. They are against change and do not wish to see any alteration in the quality of life currently enjoyed by members of like mind.

Employers

Members of this group are concerned with the development of a thriving community. Although they give priority to economic expansion and their growth they are aware that environmental quality can be instrumental in achieving and maintaining a viable market for products as well as helping to build a community.

Games and Simulation in Environmental Education 223

C.

d.

Workforce

The workers naturally wish to preserve and enhance their job satisfaction and employment prospects. They are worried by any redundancy threats and value provision of good educational services as a potential ladder to improved job opportunities.

The Uncommitted

This group represents the sector of the community usually referred to as the floating vote - people whose views, allegiances and votes fluctuate according to changing conditions. They can ask awkward questions and can be swayed by good arguments.

Ask each group to establish independently their position in relation to the issue recognized as a priority concern.

Stage 3

Bring the class together to simulate a town meeting. Let them choose a meeting chairman and a clerk. The clerk can monitor the impact of the discussion on a standard assessment form and can summarize the debate before a meeting vote is taken.

During the debriefing session encourage students to go on to:

1. Focus on particular types of issues more relevant to different environmental considerations;

2. Identify various town council member profiles related to their own governmental area and party manifestos and objectives;

3. Specify leading community lobby groups and evaluate their power and prestige;

4. Consider how different council professional officers might supply technical advice to influence discussion and improve the monitoring of public opinion and impact analysis This primary game is the first step to bringing local environmental issues into sharper focus.

Impact Assessment Sheet Physical

intensity -.- -

Positive Impact

:

Economic Social Political

Negative Impact [-IF] Almost Nil

Intensity ---++7 rz’“’

Fart II - Pedagogical Aspects 224

Practicum: Observing Students Conduct a Simulation Activity

Debriefing Discussion

1.

2.

3.

What was the meeting about? or, alternatively, What was the issue being discussed? (To build or not to build a coal-lired power plant in Barangay Bayside.)

What preparatory activities preceded the simulation activity? (Answers may include gathering of information about the proposed project and the environmental situation, Arguments for/Arguments against, and role and choker cards.)

What specific types of information are expected from the teachers? From the students?

What can be gained from an exercise like this? Answers will include:

Heightened interest and excitement in learning;

The realization that this is different from cookbook exercises;

Removal of student-teacher polarization;

Presentation of an issue using a holistic view;

Decision making experience.

What are the disadvantages of this activity? Answers will include:

Time consuming;

Requires that the teacher be knowledgeable of the situation;

Parents may not be appreciative of the idea.

At what level of secondary school can this activity be effectively done? Why?

How can the information from the simulation activity be used in a science class?

What improvements can be done to improve the activity?

If you were to rate the arguments for and against what would your decision be?

Ten Commandments for Teachers Using Games and Simulations (from Unesco, 1183)

I.

II.

III.

IV.

V.

Thou shalt not correct the minor mistakes of players.

Thou shalt not offer a better strategy that a player does not perceive.

Thou shalt not correct any elaboration or alternation of the rules of the game by participants.

Thou shalt not review in minute detail the purposes, rules and materials of the simulation game.

Thou shalt not keep perfect order. Gaming is fun and noisy.

Games and Simulation in Environmental Education 225

VI. Thou shalt not stymie any point that seems to be irrelevant to the discusion. They often are relevant, or at worst, only brief digressions.

VII. Thou shalt not restrain the moderate physical movement a game may require.

VIII. Thou shalt not answer participants’ questions about the game with “that’s not in the rules”. It is impossible for the designers of a simulation game to account for all events and questions that might arise in the course of playing.

IX. Thou shalt not admit thy lack of knowledge about a point of the game’s operation or the process under study.

X. Thou shalt not consider a simulation game as serious a form of education as less enjoyable forms.

References

CDC, Canberra (1981) EE: A Sourcebook for Secondary Education.

EMB-DENR (1980) Coal-Fired Power Plants, EL4 Reports.

ISMED Module (1984) U%ich Eneqy Source For Your Community

Unesco (1983) Guide on Simulation and Gaming for EE.

Chapter 22

L&son Planning and Development of Teaching Aids*

.

The challenge to secondary curriculum planners and educators is how to make science and technology (S & T) lessons environmentally oriented. The challenge is not really formidable, because science by its very nature is environment-based, while technology can provide the practical means of solving the environmental problems caused by the irresponsibility of man. Indeed, the environment is the proper focus of S & T. It is even proposed by avant-garde theologians that the living earth, not man alone, is the centre of universal consciousness. Perhapswith this new theology translated into classroom lessons, man, realizing his dependence on the living environment, would become less egoistic and arrogant and learn to live in harmony with nature.

Science, Technology and the Environment (STE) constitute a logical educational trinity. Each component complements and supplements the others, stressing the holistic nature of natural order. Together, the components form a powerful force that can ensure the continuity of life and the integrity of the planet earth.

S T A E

STE, an educational trinity

The science teacher should deliberately create opportunities for integrating these three components in classroom lessons. This will make the lessons relevant and meaningful. Science lessons that are not situated in the environment have a tendency to be highly theoretical and are perceived by many secondary students as impractical and unimportant. The S & T approach is based on the philosophy that science, through its many applications, should improve the quality of life of society. The STE approach goes further by guaranteeing that, so long as man lives in harmony with nature, life on earth is not endangered.

* Prepared by Dr. Adelaida L. Bago, Science Education Speciahst, UP-ISMED, Philippines.

Ta


What environmental concepts can be infused in S & T courses? The following general topics can be easily integrated even in already established S & T curricula:

1. Conservation of life support systems i.e. forests, waterways, atmosphere, agricultural lands, watersheds;

2. Promotion of genetic diversity - biological species;

3. Understanding life processes-propagation, metabolism, decay, nutrition;

4. Sustainable development - renewable and non-renewable resources;

5. Pollution -water, air, land, noise;

6. Population - family planning, health.

A creative teacher simply cannot miss the vast opportunities for infusing these environmental concerns in a wide spectrum of science concepts in the syllabus.

The main characteristics of Environmental Education as outlined in the Unesco Tbilisi conference are: a problem solving approach; an interdisciplinary educational approach; the integration of education into the community; and a lifelong forward-looking education. Clearly, environmental education is concerned with both the present and the future, drawing from the lessons of the past. it therefore aims to provide individuals with knowledge, skills and attitudes that will enable society to develop a new world view, set of values and environmental ethic. This is necessary because with STE science ceases to be a neutral or value-free topic.

The emphasis on the absolute objectivity of science contributed to a large extent to the ever decreasing popularity of this subject matter. Science is perceived by many individuals as a discipline with a lot of negativism. In contrast, STE lessons require individuals to make value judgments based on the empirical data of science and technology. This makes science and technology courses more humane which perhaps increases their appeal to students.

The syllabus structure for environmental education shows a comprehensive panorama of the knowledge, skills, and attitudes that can be developed through environment-based science lessons. Based on the model, a teacher can prepare activity-oriented lessons that can bring about the desired objectives of STE. The past chairman of IUCN, A.V. Baez summarizes these objectives as the 5 C’s of environmental education - curiosity, creativity, competence, compas- sion and conservation. The curious individuals usually acquire more knowledge and skills than the apathetic ones. Intuitively knowledgeable and skilful individuals are generally more com- petent in problem solving and hopefully more creative.

The lesson prepared for this session is on “The Greenhouse Effect”. The choice of the topic was influenced by the environmental theme chosen by UNEP for 1989 - Global Warming, Global Warning. The environmental concept is introduced by a discovery learning activity. This lesson is presented as a talking point. It is by no means perfect. With your collective experience and expertise this lesson can and should be made a lot better.

Several components were included in the discovery learning activity. These components are as follows:

1. Statement of the problem in question form;

2. The principles and concepts to be taught;

3. The materials to be used; l

Lesson Planning and Development of Teaching Aids 229

4. Discussion questions;

5. The discovery activities given in the form of instructions;

6. Critical thinking and scientific processes such as predicting, hypothesizing, analyzing, making conclusions, evaluating, etc;

7. Open-ended questions which can be used as a springboard for other activities;

8. Teacher’s notes and explanations.

As a whole the lesson was developed to illustrate the discovery-of-order-in-nature approch proposed by Helmut Hass. In this model the concept of order is defined by the following parameters:

l Order as a basic dimension

l Order as a property of a system

l The maintenance of order

l The origin of disintegration of order

In the lesson the discussion of solar energy as the source of life, its distribution and its uses stresses the holistic nature of the environment and shows order as a basic dimension in the universe. The description of the carbon cycle is an illustration of order as a property of the system. The analysis of “The Greenhouse Effect” and its importance to man suggests how the natural order can be maintained. The build-up of carbon dioxide due to the unabated burning of fossil fuels by man causes the disintegration of order (,global warming).

The power of this approach is the ability to inspire awe, admiration and reverence for the order in nature. This subtly suggests a spirituality of the earth. The discussion of the environment is not only in terms of its degraded state (disorder) but also in terms of an integral system capable of maintaining order without the harmful intervention of man. The ideal state (order) is presented along with the degraded state showing the tension that exists between them.

There is another way of looking at the lesson on “The Greenhouse Effect”. The lesson evolves from the discovery learning of science concepts (electromagnetic radiation, behaviour of light) demonstrating the greenhouse effect. This was later expanded to include the greenhouse effect of carbon dioxide in the atmosphere resulting in global warming.

A contrasting approach would be to discuss environmental concepts of certain technologies such as the fermentation of alcohol, a renewable source of energy and then later “dig in” science ideas such as decomposition, chemical reactions, thermodynmic principles, etc. into the lesson.

The second approach is the materials that can be used for the lesson you are about to prepare on the topic”Alcoho1, A Renewable Source of Energy”. This topic can also be discussed as an issue. A few years back, the Philippine Government was seriously considering embarking on an “Alcogas National Programme” which involved the blending of alcohol and gasoline. However, when the price of gasoline substantially dropped, the programme was shelved since it was more economical to use 100 per cent gasoline.

Many science teachers complain that preparing environmentally oriented science lessons entails a lot of hard work. Perhaps one reason for this is the fact that there is a dearth of lesson models to guide them in their classroom work. The challenge for us, therefore, is to prepare a


rich inventory of science lessons that the teachers in our region will find appropriate to use in their respective science classes.

Background Materials on A Renewable Source of Energy - Biofuel

Many crops are grown for the production of energy. These crops can produce energy directly by burning as in the case of wood or indirectly by producing alcohol as efficient fuel. Energy derived from plants is called biofuel. The use of biofuel would reduce dependence on fossil fuels and the need to import gasoline products-

One of the most suitable materials for alcohol production is sugar cane. Alcohol may be obtained through the activity of enzymes secreted by very tiny living organisms. The process is known as fermentation. The micro-organism used is Saccharomyces cerivisiae, a strain of yeast. Alcohol can also be obtained from molasses, a by-product of sugar cane processing. This is why many sugar factories also operate alcohol production auxiliary plants.

Alcohol may be used to light homes in areas where electricity is not available. It can also be used for heating and as a substitute fuel for gasoline. In Brazil, alcohol is used to run more than 3 million vehicles; replacing about 60 per cent of the country’s gasoline requirement. It is also used to power agricultural tractors, water pumps and small electric generators.

As fuel alcohol does not contribute to air pollution it may be blended with gasoline or diesel in varying proportions and used as fuel for motor engines.

Although the production of alcohol might seem uneconomical because of the high cost of production, it opens opportunities for rural development, employment generation, increased self-reliance and reduced pressures on dollar reserves.

Sample Lesson. The Greenhouse Effect

I. OBJECTIVES:

At the end of the lesson, the student should be able to:

1. Classily electromagnetic radiations;

2. Discuss the behaviour of light;

3. Explain the “Greenhouse Effect”;

4. Relate the principle of the “Greenhouse Effect” to the reported global warming;

5. Identify the greenhouse gases and their sources;

6. Discuss the disastrous effects of global warming;

7. Propose solutions to global warming.


II. INSTRUCTIONAL MATERIALS:

Improvised equipment for discovery laboratory activity, overhead projector, transparencies, blackboard and chalk.

III. INSTRUCTIONAL METHODS:

A. Investigatory Laboratory Activity

Problem: What happens to the temperature inside a box when you vary the cover materials?

Principles and Concepts to be taught:

1. Transparent materials transmit visible light.

2. Visible light is absorbed by the pigment of opaque materials reflecting only the light that is the sa l& e colour as the pigment. Opaque materials emit heat (infra-red radiation).

3. The earth’s surface absorbs visible light, reflects it and emits infra-red radiation.

4. Transparent materials trap the heat emitted by the earth (Greenhouse Transparent Effect).

TRANSPARENT OPAQUE

White Light

White Light

24

WHITE SURFACE

Only red light is reflected

RED OBJECT

CLEAR GLASS

Materials needed:

0 4 identical cardboard boxes (e.g. shoeboxes approximately 30 x 20 x 15 cm)

l 4 thermometers

0 tape

l scissors

0 piece of glass

l clear plastic sheet

l piece of cardboard

-..... --- “-.. --II_L_I/


Instructions:

1. Cut a hole in all boxes as shown.

hole

lTi!zo fi? lzl 2. Punch a hole in one end of each box and insert a thermometer.

thermometer

\ n

glass cover plastic cover cardboard cover

3. Place a glass cover on one side of one box.

4. Place a plastic cover on the second box.

5. Place a cardboard cover on the third box.

6. Leave the fourth box uncovered.

7. What do you predict will happen?

37 q

I open

In the following space describe your predictions for the reading of the thermometers in the 4 boxes after 3,5, 10, 15 minutes.


8. Use the table shown below to collect your data.

5 mins

10 mins

15 mins

20 mins RI=

9. Record the temperature on each of the 4 thermometers before you take your boxes out into the sun.

10. Leave the apparatus in the direct sunlight for 20 minutes.

11. Record the temperature of each thermometer in the table corresponding to the indicated time.

Interpretation of data

1. What were the changes in temperature before and after placing each box in the sun?

Box 1

Box 2

Box 3

Box 4

2. In which box was the greatest difference in temperature? .

3. Is there a difference between the temperature change in the boxes with the clear glass and clear plastic covers?

4. Why did we need box 4?

--- _..... -_-. .


Conclusions

1. What reason can you give for the difference in temperature gain for the 4 boxes?

Answer: To examine the effectiveness of glass, plastic and wood in transmitting light and trapping heat, it was necessary to compare the temperature inside the boxes with the temperature in the box without any cover. Box no. 4 is called a “control” for your investigation.

2. Describe in your own words what is meant by a “control”.

3. Did these results agree with your prediction?

Explain any differences between your results and your prediction.

The difference that you observed in the temperature gain is called The Greenhouse Effect.

4. Explain why clear glass or clear plastic is used to build a greenhouse.

The greenhouse has been invented to meet the particular need of growing plants in colder climates and in winter time.

5. Explain in your own words the function of a greenhouse.


6. What other possibilities for experimentation did this activity suggest to you?

B. Lecture-Discusion

1. The sun is the principal source of energy on earth.

2. The energy given off by the sun is called electromagnetic radiation, which is a continuous spectrum of frequencies.

3. The earth absorbs the shorter wavelength (visible light) radiation and emits the longer wavelength (infra-red) radiation.

4. Carbon dioxide is a greenhouse gas. Like glass and plastics, carbon dioxide transmits visible light and absorbs the infra-red radiations emitted by the earth.

5. Without carbon dioxide, the temperature on earth would be 20 to 30 degrees C lower.

6. There is a continuous build up of carbon dioxide in the atmosphere resulting in increase in global temperature.

7. There are other greenhouse gases in the atmosphere which contribute to global warming.

Questions for discussion:

1. How is solar energy distributed on earth?

2. What are the different types of radiations, their properties and their implications to man?

3. What is the importance of carbon dioxide to human?

4. What are the sources of carbon dioxide in the atmosphere? the other greenhouse gases?

5. What are the effects of the increase in the concentration of greenhouse gases in the atmosphere?

6. How will you help prevent the continuous build-up of greenhouse gases in the atmosphere?


IV. EVALUATION:

1. Objectives l-5 can be measured by an oral or written examination.

2. Objectives 6-7 can be measured by the extent of the students’ participation during the discussion on effects of global warming and the preventive measures against the build-up of carbon dioxide in the atmosphere. The students can also be made to prepare a plan of action to help solve the problem of global warming.

References:

Astronomy. (1981). Curriculum Branch, Education Department of Western Australia.

Carin, Arthur A. and Robert B. Sund. (1875). Teaching Science Through Disco\lery. Charles E. Morill Publishing Co. and A. Bell & Howe1 Co., USA.

Hungerford, R. Harold. (1978). Strategies for Developing an Environmental Education Cur- riculum. Unesco.

Holman J.S. (1987). ContrastingApproaches to the Introduction of Industry and Technology into the Secondary Science Cuniculum. Education, Industry and Technology, (31-37) Per- gamon Press.

Hass, Helmut. (1987). Order and Disorder-in Nature:Action-based and Interdisciplinary Environ- mental Education in the Natural Sciences. The Environment and Science and Technology Education, (85-95) Pergamon Press.

Knamiller, G.W. (1987). Issue-based Environmental Education in Developing Countries. The Environment and Science and Technology Education, (157-161) Pergamon Press.

Science and Technology Education, Document Series No. 31. (1988). Unesco, Paris.

Science Syllabus (1984). Curriculum Branch, Education Department of Western Australia.

Chapter 23

Supervision and Monitoring of EE Classes*

The learning acquired by teachers concerning the teaching of environmental education may be transitory or left unused if not followed through. Some learning might be inadequately applied, incorrectly applied, or not applied at all.

The purpose of teacher supervision is to see that teachers correctly apply what they have learned toward the effective and efficient teaching of their subjects. The role of the supervisor is to guide the teacher in maximizing the application of his learning toward developing correct concepts, attitudes and skills in the learners.

The supervisor’s role is not to find fault but to identify the strengths and weaknesses of the teacher. Based on his observation of a teacher in an actual teaching sequence, the response or behaviour of the students, and the atmosphere of the learning situation, he can identify which good points need to be sustained and which poor points need to be improved or remedied. Supervision takes on some evaluation function because it involves observation and making some corrective or catalyzing action.

Evaluation may be defined as the process of gathering information which can be used as a basis for forming judgments, which in turn can be used as a basis for making decisions. This definition shows some commonality of function in evaluation and supervision.

Supervision is also sometimes confused or used with monitoring in mind. The two, although related, are not entirely identical.

Monitoring is periodically watching the progress of a programme or project in order to find out if it is being carried out as planned, taking note of weaknesses and strengths, and carrying out immediate corrective action where necessary.

In all three activities - supervision, monitoring and evaluation - there is a need for instruments to obtain needed information.

Instrumentation

An instrument is a device or tool meant for a specific purpose or function. For example, a paper and pencil test on concepts in environmental education can be considered an instru-

* Prepared by Dr. Milagros Ibe, Professor, College of Education, University of the Philippines, Diliman, Quezon City.


ment. Its purpose might be to determine the extent of the learners’ knowledge, understanding and ability to apply concepts and principles about the environment.

In supervision and monitoring, most of the instruments that will be needed go beyond paper and pencil tests. They would include non-cognitive assessment tools for assessing attitudes, perceptions, and beliefs. Or they could be tools for obtaining information through direct observations (like checklists) or interviews.

Types of Instruments

According to the response format or to the recording of the information, instruments can be either structured, semi-structured, or unstructured. The structured kind includes:

a. Rating scales;

b. Checklists;

c. Alternate or multiple-response items;

d. Likert scales;

e. Semantic differential.

In these instruments, options are given, and the respondent simply chooses the options that match his answers.

The unstructured kind includes:

a. Open-ended questions like those asked in an interview;

b. Sentence completion items;

c. Projective tests (e.g. “tell a story”; “draw a picture”; etc.);

d. Essays/story telling;

e. Situation tests;

f. Moral dilemmas.

Ranking items could be considered semi-structured. So are situation tests with given options but the respondent is asked to justify or support his choice of a particular option.

What to Consider in Choosing an Instrument

The choice of an instrument is based on the following factors:

Purpose. For what is the information going to be used? What is the instrument to measure? Is it to measure knowledge, attitude, perception or behaviour? For each of these, there are only particular instruments which will be appropriate. For example, a Likert-type scale is not designed to measure knowledge.

Type and nature of information to be obtained. Is the intent to measure perceptions or actual information/data? Or is it meant only to get some indicators of behaviour inclina- tions or beliefs?

Supervision and Monitoring of EE Classes 239

Ease of use and scoring. Some instruments yield qualitative information which is difficult to score (e.g. situation tests; sentence completion items). Others are easy to score but are difficult to administer to certain groups (e.g. Semantic Differential Tests).

Reliability of recording. The instrument must work in such a way that the respondent is clear about how he is to record his response. Otherwise, his answers will not be valid nor reliable.

Objectivity. The numerical or quantitative score yielded by the instrument should be the same for an individual no matter who scores it.

Practicability. This characteristic of an instrument relates to cost and efficiency in terms of time and in its ease of administration to large groups. Individual tests or interviews often fail to meet this criterion.

Steps in Constructing and Developing Instruments

1. Identify the key concepts for which measures are to be obtained and define them. For example, the concept of “environmental consciousness”. What does it mean? Or what does “Valuing our natural resources mean”?

2. Identify indicators of the concept. For example: When do we say that a person is “environment conscious”? What are the marks ofsuch a person. What behaviours show that a person values his environment?

3. Translate the indicators into items.

4. Select the item type or scale to use. Will you use a 5point or a 4-point scale? What scale descriptors will be appropriate?

5. Write the first draft of the instrument. This will consist of several items designed to measure particular knowledge, orientations, perceptions, practices/behaviours, or traits.

6. Critiquing of the first draft. This draft should be carefully examined by the constructor and should be shown to his colleagues in the same field for their comments and suggestions. This is to ascertain the face validity of the instrument. The concern at this point is “Does the instrument appear to be an appropriate measure of what is aimed to be measured?”

7. Revise the first draft based on comments and suggestions obtained.

8. Try out the revised form on 10 to 20 individuals to determine whether the instrument is comprehensive and to estimate the average time to get it administered or answered. Solicit comments from the try-out group. Identify items which were not understood or were not answered. These could be problematic items.

9. Revise based on suggestions. Prepare the third draft.

10. Administer the third draft.

11. Determine its validity and reliability indices.


Validity and Reliability

The validity of the instrument can be established through:

1. Content validity - through the sampling of items across the domain;

2. Face validity - by subjecting it to the comments of specialists in the field (e.g. specialists in environmental education and evaluation);

3. External Criterion validity - through comparison of scores of persons identified as possessing the trait and those who are known not to possess the trait.

The reliability of an instrument can be established through the use of the Kuder- Richardson Formula (KR-20) or the Coefficient Alpha. KR-20 is used if there is a clearly right/correct answer to an item, as in the case of an achievement test. Coefficient Alpha is used in non-cognitive assessment instruments where there are not right or wrong answers, as is the case in an-attitude inventory.

KR-20:

Reliability

where N

Pi

9i 2

Coefficient Alpha:

RTT

where Si2 = the squared standard deviation of the scores on item 1 correctly

RI- = the reliability index

N N i=l piqi =

N-l l-

2

= No. of items in the test = the percentage of the examinees who answered

item i correctly

= C1 - Pi) = squared standard deviation of the test scores

of the total group

N 2

N i=l Si = N-l

l- -- 2


Limitations of Educational Measures

Grades, scores in tests, and the scores in inventories are all samples of educational measures. They suffer from limitations. Specifically, they are only indirect measures rather than direct measures like the measures of length, time or speed we get in the physical sciences. Educational measures are relative and not absolute. They are used mainly for classification purposes.

For example, a scale for attitude toward conservation of natural resources is used simply to find out who has less favourable or more favourable attitudes. Educational measures are also incomplete; an instrument constructor or developer will not likely be able to include all possible items for measuring a trait or characteristic. Educational measures are open to errors of measurement. They cannot be 100 per cent reliable.

Problems of Measuring Non-cognitive Characteristiics

The problem of definition. Many of the terms we use and which we think we know are hard to define. For example: “environmental anxiety” or “social responsibility” are used by people in everyday conversation, but defining the term or phrase is another matter. Until we are able to define the term or trait both conceptually and operationally, we cannot measure it.

Response set. Some individuals have a particular way of responding. In a 5-point scale for example, some persons play things safe by taking the middle ground or “3” on the scale. Others might be overly generous, optimistic or liberal, hence are likely to score on the upper end of the scale. Others would be very conservative or stingy in their marks. Still others might have the response set which identifies the right hand end of the scale as the best answer even when the scale descriptors are reversed. All these lead to errors of measurement.

Faking. Some respondents, wishing to project a favourable image of themselves, give fake or incorrect answers.

Low validity and reliability. Errors of measurement lead to low reliability. Problems of trait definition and item sampling create low validity.

Problem of interpretation. Determining what a score means with respect to the trait being measured is difficult. What do variations in scores indicate? Do they mean real differences?

Guidelines for Writing Attitude Scale Items

1. Avoid statements which refer to the past rather than to the present.

2. Avoid statements that are factual or likely to be interpreted as factual.

3. Avoid statements that may be interpreted in more than one way.

4. Avoid statements which are irrelevant to the psychological object under consideration.

5. Avoid statements that are likely to be endorsed by almost everyone or almost no one.

6. Select statements that are believed to cover the entire range of the affective scale of interest.

Part I/ - Pedagogical Aspects 242

7. Use simple, clear and direct language.

8. Use short sentences, rarely exceeding 20 words.

9. Each sentence should present only one complete thought.

10. Avoid using specific determiners like always, none, never.

11. Use words like only, just, merely with moderation.

12. Use simple rather than compound or complex sentences.

13. Use words which are at the respondent’s level.

14. Avoid using double negatives.

Different Types of InstrumentsPechniques

1. Rating scales

2. Likert scales

3. Semantic differential

4. Alternate response items

5. Sentence completion

6. Open-ended items

7. Observation checklists

8. Situation tests

9. Projective techniques

10. Ranking items


1.

2.

3.

4.

5.

6.

7.

8.

9.

Sample Likert Scale Items

Instruction: Circle the letter which matches your extent of agreement or disagreement with each of the following statements. The letters have these meanings:

SA - Strongly Agree

A - Agree

U - Neutral/Undecided

D - Disagree

SD - Strongly Disagree

Begin here:

All of us are guilty of polluting the environment.

Modern technology leads to more evil than good.

This earth will be less polluted if birth control policies are adopted by every country.

The depletion of natural resources is brought about mainly by greed and love for money.

Environmental education should be given only to adults.

This world will be a better place to live in if man does not tamper with nature.

Population growth is not a serious problem because this country can support even 3 times its population.

We should re-use plastic knives, forks and spoons instead of throwing them away.

All food items should be packaged in plastic containers.

10. People have no right to question their neighbours’ way of disposing of their garbage.

Some reminders on writing Likert scale items:

1. Use simple, short, opinionated statements.

2. Be sure the statement conveys only one idea.

3. Avoid using factual statements.

4. Use statements on which opinions vary widely.

5. Avoid using double negatives.

SA

SA

SA

SA

SA

SA

SA

SA

SA

SA

A

A

A

A

A

A

A

A

A

A

U

U

U

U

U

U

U

U

U

U

D

D

D

D

D

D

D

D

D

D

SD

SD

SD

SD

SD

SD

SD

SD

SD

SD

-. -_- -.__. . --.


6. Try to have as many negatively oriented statements as positively oriented ones.

7. Have at least 10 statements in the set.

Ranking Type Items

Instruction: Rank these problems from the most to the least serious as they affect our school. Write “1” on the blank for the most serious, “2” for the next most serious, and so on.

1. Garbage disposal

2. Noise pollution

3. Overcrowded classrooms

4. No piped water

5. Air pollution/foul air

6. Rats and cockroaches

7. Polluted water

8. Clogged canalsidi tches

9. Traffic congestion on streets bordering the school

lO.Vandalism (writings on walls)

ll.Others (specify)


Practice/Behaviour Rating Scale

Rate how often you do the following behaviours by checking (/) the column that matches your answer.

Use this code:

V - Very Often

0 - Often

S - Seldom

N - Never

How often do you:

1. burn your garbage?

2. put your garbage in a big plastic bag for pick-up by the garbage truck?

3 _ . separate the plastic from other types of materials in your trash piles?

4. compost/bury your trash?

5. advice members of your family to conserve water?

6. check if all lights and electric appliances are turned off before you leave your house?

7. report a leaking street pipe to concerned authorities?

8. remind children in your neighborhood not to litter?

9. leave the faucet on while you brush your teeth?

10. use detergents for washing clothes and dishes?


Use of Visual Aids

1. Number of aids used‘?

0 1 2 3 4 5 6 None at all Very Many

2. Appropriateness of aids used?

0 2 3 4 Very Inappropriate Very Appropriate

3. Variety of aids used?

0 1 2 3 4 5 Very Little Very Much

4. What visual aids were used?

blackboard

charts

pictures

drawings

concrete objects (e.g., actual samples)

slides

others

5. Was the teacher at ease in using the aids?

Semantic Differential

Mark with “X” the blank space which corresponds to your judgment. Read both descriptions.

1. The materials used in this training programme are:

Interesting ___ ___ ___ ___ ___ ___ ---

Weak --- _-- --- --- --- --- ---

Useful --- _-- --- --_ --- ___ ---

Easy ___ --- --- -_- --- --- ---

Irrelevant ___ ___ ___ ___ ___ ___ ---

Comprehensive --- _-- ___ ___ ___ ___ ---

Inapplicable -__ _-_ ___ ___ ___ ___ --_

Boring

Strong

Useless

Difficult

Relevant

Narrow Applicable


2. The methods used in this training programme are:

Interesting Weak

Useful Easy

Irrelevant

Comprehensive

Inapplicable

___

-__

---

---

--_

---

---

-_-

_--

---

---

-_-

---

---

---

---

---

---

---

---

---

---

---

---

---

---

---

---

---

---

--- ---

---

---

---

--- --- Boring --- --- Strong --- --- Useless --- --- DiEficult --- --- Relevant --_ --- Narrow --- --- Applicable

Sample Test Items

Multiple Choice

1. Which statement(s) is (are) true of hard water?

i. The minerals in it cause scale formation.

ii. It requires more soap for washing.

iii. It contains certain minerals which make it ideal for drinking.

a) i only d) i and ii

b) ii only e) i, ii and iii

c) iii only

2. Which of the following is a pollutant of gasoline but not of diesel fuel?

a) hydrocarbons d) organic acids

b) carbon monoxide e) nitrogen oxide

c) aldehydes

3. Which of these is not a symptom of lead poisoning?

a) abdominal pain d) numbness of hands and feet

b) bleeding/hemorrhage e) anemia

c) tingling pain and cramping of muscles

4. “Black lungs” is a condition which often develops in:

a) carpenters d) coal miners

b) fishermen e) farmers

c) occasional smokers

5. Which of these is the most detrimental effect of oil spills from tankers?

a) They slow down the ship.

b) They slow down the movement of water animals.


c) They kill fishes and other marine life.

d) They could cause fires.

e) They make the water unfit for swimming and rowing.

6. In 1838 Schwann, on the basis of his own observations as well as the observations of others, advanced the tentative conclusion that all living things are composed of cells. This statement, when first made in 1938, was:

a) an assumption. d) an analogy.

b) an observation. e) a law.

c) a generalization.

Situation or Moral Dilemma

Paul and you have been very close friends since grade school. As high school students you help each other in your lessons. You tend to depend much on him.

One day you chance on Paul using drugs. He admits to you that he has been using drugs for almost a year. He threatens to harm you if you tell his parents. What would you do? Why? (open-ended type):

Structured type (with options provided)

1. I will tell his parents, even if he says he will harm me.

2. I will seek advice from other people like teachers.

3. I will follow his wish and keep his secret.

4. I will try to talk sense into him.

5. I will report him to the authorities.

6. Others (specify)

Because

“. _-..I .,.... “..“.___ .,“. .


Open Ended Items

Instruction: Answer the following questions.

1. In your opinion, what are the two or three most important problems that need to be solved in the years ahead to make Quezon City a better city?

2. Name the two most serious environmental problems in your community.

3. What do you consider an appropriate punishment for persons who carelessly throw their trash?

.

Sentence Completion Items

Instruction: Read the opening phrase or clause and then complete the sentence by writing on the blank the first thought that comes to your mind?

1. When I see garbage piled up in the sidewalk, I

2. The best way to get people to realize the depletion in our forest resources is to

3. People would be more concerned about environmental education if

Chapter 24

Research in EE: Its Implications for Classroom Teaching and Teacher Training*

The whole world’s attention is now focused on the state of the environment. Degradation of the environment brought about by developments in science and technology and the need to satisfy the demands of the growing population arc becoming more visible. As scientific and technological knowledge grow exponentially there is a corresponding increase in the demand for natural resources and in the number and complexity of environmental problems associated with their exploitation.

Environmental education aims to “aid citizens in becoming enviromentally knowledgeable, and above all, skilled and dedicated, willing to work individually and collectively, toward achieving and/or maintaining a dynamic equilibrium between quality of life and quality of environment.”

To achieve these aims we have to look again into the context in which environmental enhancement concepts are integrated into classroom teaching. Is it education about the environment, concerned with providing cognitive understanding including skills needed to obtain this understanding? Or is it education for the environment, that is, directed towards environmental preservation and improvement?

Why do Research on EE?

To answer this question we raise other questions.

1. What science and technology information helps solve environmental problems that are associated with the use of technological processes, products or tools?

2. How can integration of EE enhancement concepts into teaching develop the formal processes of thinking of students?

3. What kind of strategies would suit the needs of different students at different grade levels so that they develop into environmentally oriented individuals?

4. How can the gap between what has been achieved in EE in developed countries and in developing countries be bridged, and in a shorter time?

* Discussion paper by Dr. Merle C. Tan, IJP-ISMED, Diliman. Q.C., Philippines.


5. What socio-economic and cultural factors affect the success of EE programmes?

6. What teaching methods are necessary to enable students to understand these factors?

7. How can we encourage more participation in EE activities without causing conflict with government development programmes?

8. What educational technologies are suitable for increasing environmental consciousness? Which of these technologies can best be developed using indigenous resources?

9. What values could be taught and at what levels?

These are some of the reasons why we need to do research in EE.

Areas of Research in Environmental Education

These ideas may be applicable to any area of education.

1. General research includes:

a. The search for conditions in which learning is optimized or with studies on the abilities acquired by children at different stages of intellectual development based on learning theories;

b. Analysis and selection of subject matter and teaching approaches at different levels of education;

c. Curriculum development research based on learning theories.

2. Content-oriented research includes:

a. A critical analysis of a curriculum, often of a comparative nature;

b. Development of new curricular materials, courses and teaching units reflecting an interdisciplinary approach;

c. Introduction of new research methods and techniques into environmental education.

3. Research into methods of environmental education focused on methods of teaching which will enable students of all levels to understand and use knowledge about science and environment to achieve other objectives of environmental education.

4. Research into teaching aids and use of educational technologies studies the effects of slide presentation or VTR in EE - development work involving tapes, slides, OHP, computer in EE classes.

5. Research in Assessment and Evaluation

Assessment focuses on students’ attitudes, knowledge and abilities, courses of curricula, teachers’ working conditions and environmental influence on education as a whole.

Evaluation focuses on experimental techniques and apparatus, in-service needs of teachers involved in environmental education and teachers’ approaches to new curricula.

Research in EE 253

Many available studies about the environment are technical in nature. For example, those focused on determining sulphur dioxide level in air and their effects on rice, or the extent of pollution in Laguna de Bay are purely environmental science researches but are important inputs to the content of EE.

Examples of EE Research from UP-ISMED Library

Category 1. A Conceptual Framework for Environmental Education Adapted to the Philippines Environment by Paz C. Medel(l974).

Category 2. Development and Evaluation of Reading Materials for Promoting Public Understanding and Environmental Issues in the Philippines by Lilia M. Rabago (1981).

Category 4. Videotape Instruction vs Instructions by Conventional Method in Teach- ing Photosynthesis by M. Combatir, (1983).

Category 5. A survey of the Environmental Knowledge, Comprehension, Respon- sibility and Interest of the Secondary School Students and Teachers in the Philippines by Lcticia Cortes (1986).

Category 5. Development of an Instrument to Determine Students’ Views on Pollu- tion by Fe de Guzman (1986).

Category 5. Effect of Outdoor Activities on the Achievement of Grade 6 Pupils in Ecology by Y. Roman (1980).

Method of Data Collection

A. Interview/Questionnaire

0 using real situations/diagrams/pictures

0 using questions

l asking students to visualizc the problem at the molecular level

B. Concept/Attitude Inventory

C. Word Association

D. Writing about Issue or Problem in their Own Words

E. Multiple Choice

What Research can be done by teachers?

Research in EE is necessary to increase the effectiveness of knowledge and skills transfer from teacher to students. Teachers can do research at three stages.

1. Before the transfer process (motivation stage)

2. During the teaching-learning processes

3. After the transfer process (evaluation stage)


What are the implications of this research for classroom teaching and teacher training?

The implications may vary with the research but the fact is that it is not possible for teachers to effectively use a research approach to EE unless he/she gets involved in research.

Workshop

Choose as partner a participant you have not worked with in previous groupings.

1. Read one research paper

2. Give the following

a. objectives of the study

b. method of data collection

c. findings

d. implications for classroom teaching

e. implications for teacher training

3. Categorize the paper analysed based on the areas of research discussed.

4. List topics in environmental education that teachers can research on.

Sample Output

1. Title of paper: Development of an Instrument to Measure Student View on Pollution

2. Researcher: Fe S. de Guzman

3. Type of Research: Research on Assessment and Evaluation

4. Objectives:

a. To find out students’ views on pollution.

b. To develop instruments from interview results in order to identitjl students’ views in pollution.

5. Method of Data Collection:

a. Taped individual interviews of 24 students from Form 3 and 4. Interviews were based on students’interpretation of pictures related to pollution. These interviews were transcribed.

b. A 24-items multiple choice question based on interview results was given.

6. Findings of the Study:

a. The sample group interviewed showed varied views of pollution.

b. The result of the second method showed similar response to the first method.

c. Regardless of their educational level, the students’ pattern of response was similar.

ResearchinEE 255

7. Implications to Classroom Teaching:

a. Teachers should be knowledgeable of the content of EE to determine which student views are non-scientific.

b. The ideas that students have prior to teaching are important in planning lessons and correcting whatever “wrong” ideas they have.

c. Research findings on pollution concepts can be incorporated into the content of an EE curriculum.

. -.---.-.. _-..

Appendices

.

.

Appendix I

Exemplar Lesson Plans

Lesson Plan 1

Topic: Alcohol and Alcoholism

Strategy: Role play

Objectives

At the end of the lesson, the student should:

l Have acquired planning and organizing skills in coming up with a play;

l Be able to discuss social effects of alcohol addiction;

l Have acquired skills in communicating and cooperating with other group members;

l Be able to deduce social and value-related aspects from their observations of the play;

l Be able to evaluate social values gathered from the portrayals in the play;

l Be able to clarify a stand on issues.

Instructional Materials

Classroom furniture (appropriately arranged), newsprint for background drawing of the scenes, coloured drawing pens, appropriate attire, a bottle labelled wine or alcoholic drink.

Procedure

1. Prepare a brief description of the scenes that are to be portrayed in the play, e.g.:

Scene 1:

A drunken father gets home late at night. A quarrel starts involving the father, the mother and their teenage daughter. Meanwhile, the next-door couple (neighbours) is disturbed by the quarrel.

Appendices 258

2.

Scene 2:

The drunken father suffers the consequences of being late to his office. &Iis boss summons him to his office.

Scene 3:

The drunken father has an appointment with his doctor on his liver problem. The doctor advises him regarding his critical condition. .

Assign a group of students to play the following roles to be portrayed in the three scenes:

drunken father

battered wife (victimized wife)

teenage daughter (neglected daughter)

couple ( neighbours affected by the alcoholic)

a doctor

the drunkard’s employer

3. Give the assigned group the brief descriptions of the scenes.

4. Instruct the group to study the play and make appropriate preparations.

5. Ask the students to do library research or interview a doctor on aspects related to behaviour of an alcoholic, diseases associated with alcoholic drink, background information on this health hazard.

6. At the end of the role play:

l Elicit from the students the sympathy they have for the characters being played.

. Finally, ask the students about the good uses of alcohol as well as bad effects of alcohol and then make them state their stands on the issue, “Should alcoholic drinks be banned or not?”

7. Give the students the following test as a form of evaluation. If time is short, the discussion on whether or not alcoholic drinks be banned will take an evaluative nature.

Cognitive

e.g. Which of the following products of alcohol oxidation in the liver causes nausea?

a. formaldehyde

b. formic acid (methanoic acid)

c. acetaldehyde (ethanol)

d. acetic acid

e. butanoic acid

Exemplar Lesson Plans 259

Attitude

e.g. Circle the letter which shows your extent of agreement or disagreement with each of the following statement.

SA : Strongly Agree, N : Neutral, SD : Strongly Disagree, A : Agree, D : Disagree

The consumption of alcoholic beverages should be discouraged among teenagers.

Value

e.g. Every day your neighbours quarrel because one of the family members is an alcoholic. What should you do? Rank your decisions as such:

1. is the most important

2. is the second most important and so on

a. Advise the other family members to get the drunkard to see a doctor.

b. Ignore your neighbor’s problems.

c. Talk sense into him by discussing the health hazards of alcoholism.

Why?

Behavioural Techniques

e.g. Rate how frequently you do the following behaviour by putting (x) in the column provided.

V : Very Often, S : Seldom, 0 : Often, N : Never

How often do you do the following whenever you have a serious personal problem?

a. Drink alcoholic drinks to get over it.

b. Discuss the problem with an elderly person or a close friend.

C. Sleep on the problem.

d. Put the blame on other people who you think caused the problem.

e. Analyse the cause of the problem yourself and see what can be done about it.

Appendices 260

Lesson Plan 2

Topic: Air Pollution from Burning of Fuel

Target group: Lower Secondary School

Objective

To compare the polluting effect of burning various fuels.

Materials

1 burner half-filled with alcohol

1 burner half-filled with kerosene

1 candle

3 evaporating dishes

1 matchbox

Procedure

Light the candle and allow it to burn for 30 seconds. Place an evaporating dish with its bottom 2 cm over the flame of the candle for 1 minute. Repeat the same procedure for the two burners.

Answer the following:

1. Describe the colour of the three flames.

2. Is there any substance deposited at the bottom of the evaporating dish placed over the candle tlame? If there is, what is the substance called?

3. Did the same thing happen at the bottom of the evaporating dish which was placed over the kerosene flame?

4. How about the evaporating dish placed over the alcohol flame?

5. Which of the three fuels used in this activity will contribute to air pollution? Which ones will not?

Teaching Hints

If this activity was introduced in a chemistry class discuss the nature of the deposit and the chemical reaction involved in producing the deposit (unburned carbon and soot). Relate the results of the activity to the plan of using alcohol as a substitute for crude oil as fuel. Discuss the advantages and disadvantages of using alcohol of a mixture of gasoline-alcohol (gasohol) as fuel especially in the transportation industry.


If this lesson is a physics class, it has to be modified to enable students to compare the heating values of the different fuel source. The advantage/ disadvantages of using alcohol fuel can follow.

If this lesson were in a biology class, ask student to do some activity like the production of alcohol through fermentation. Introduce the advantages and disadvantages of using alcohol as fuel during the post-laboratory discussion.

Evaluation

Items include the cognitive, manipulative, and affective aspects of the alcohol-as-fuel issue.

Lesson Plan 3

Topic: Conservation of Natural Resources

Target Group: Lower Secondary School

Objectives

At the end of the lesson, the students should be able to:

l Identify the different natural resources;

l Identify and understand the role of natural resources in everyday living;

l Enhance their level of awareness on the state of degradation and depletion of natural resources; and

l Suggest measures for protecting and conserving natural resources through such things as campaign programmes and poster-making.

Methods

A. Motivation/Set Induction

1. Pictures showing different natural resources such as water, soil, forest, wildlife, fossil fuel like petroleum oil and minerals.

2. Interaction on the pictures to find out the level of awareness of the current status of natural resources in their respective localities.

B. Lesson Proper/Activity Proper

1. Division of the class into groups for activity work. Each group is assigned a natural resource.

2. Group discussion about the natural resource assigned to it. Each group has to discuss where the natural resource comes from or give a short description of the

natural resource, how it is used in the group members’dailylives, why these natural resources are getting depleted or degraded and how these resources can be protected, preserved or conserved, Each group can also suggest campaign strategies for use in carrying out its plan.

3. Group presentation of output.

4. Class reaction on each group output.

5. Summary of the points/items presented. Bringing out of concepts arising from the items presented.

C. Assignment

The students are asked to take note of the environmental problems concerning the natural resources in their locality for sharing during the next class session.

Instructional Materials

Pictures or posters or transparencies, OHP, blackboard, chalk.

Concepts to be included

1. Natural resouces such as fossil fuel, minerals, water, soil, forests and wildlife are there for man’s use and happiness. As such, they must be properly utilized.

2. Improper use of natural resources will lead to their degradation and depletion.

3. Renewable/nonrenewable resources must be properly managed and protected to optimize and maximize their utility.

4. Conservation measures are necessary in the proper management of natural resources.

Sample Evaluation Items

1. What makes a resource renewable, nonrenewable?

2. Which of the following natural resources are renewable? nonrenewable?

(a) fossil fuels, (b) water, (c) soil, (d) wildlife, (e) forest

3. What human activities related to use of natural resources lead to environmental degradation? .

4. How can these natural resources be conserved?

5. What can you do to conserve natural resources?


Lesson Plan 4

Topic: Overpopulation

Target Group: Lower Secondary School

Objectives

l Students explain the concept of overpopulation and its effect.

l Students develop awareness on the overpopulation problem.

Concepts

1. Overpopulation depends on birth, deaths and migration patterns.

2. Overpopulation can cause poverty, pollution unemployment, overcrowding, crime, high cost of living, etc.

Procedure

Step 1. Teacher shows a picture and allows the student to think for about one minute. Then teacher asks questions from one to three students based on the pictures.

Questions:

l What messages can you get from the picture?

Answers: Overcrowding, too many people in one small area, overpopulation.

l What causes overpopulation?

Answer: Birth, deaths, and migration pattern.

Step 2. Teacher divides the student into four groups (5-6 students/group). Each group will be given a case study (Appendix 1) on overpopulation. Student reads the case study then discusses and answers the question. (5-6 minutes).

Step 3. Each group presents its output. (8-10 minutes)

Step 4. Teacher discusses the similarities in the output of each group. Students write the similarities on the blackboard. (5 minutes).

Step 5. Teacher shows pictures on the problem of overpopulation. Asks students to tell what problems arise from overpopulation.

Answer should include: pollution; unemployment; high cost of living; overcrowding; congestion.

Step 6. Teacher asks students to give suggestions on how to overcome the overpopulation problem?

Appendices 264

Family planning

Migration to other places/towns with less population density

Materials

pictures about the effects of overpopulation (2 pictures)

a case-study

transparency, overhead projector

blackboard and chalk

Evaluation

Teacher ask students to write:

l Problems of overpopulation in their notebook;

0 Suggestions to overcome the overpopulation problem at the individual (student) level and at the government level.

Appendix I1

Sample Instruments for Assessing Students’ Achievement

Part A: Multiple Choice

Direction: Choose the best answer for the following items. Write your answer on the sheet provided. Please do not write anything on the questionnaire.

1. Besides water and solar energy, which of the following is required by green plants for photosynthesis?

a. nitrogen gas b. oxygen gas

c. carbon dioxide gas d. noble gases

2. Which of the following are among the gases produced when fossil fuels are burned?

a. CO2 and 02 b. CO2 and SO;!

c. SO2 and 02 d. CO;? and N2

3. Why is the rhinoceros threatened with extinction?

1. Its natural habitat, the forest, is being cleared rapidly for development.

2. Its horns are much sought after as souvenirs and medicine.

3. It is a dangerous animal.

4. It is a slow moving animal.

a. (1) and (2) b. (U(2) and (3) c. (2) and (3) d. (1) and (4)

4. How would you teach students ways to conserve the giant leatherback turtles?

a. Take them to the turtle beach and watch the turtles hatch their eggs.

b. Show them films about artificial hatching of turtle eggs and caring of the baby turtles before releasing to the sea.

Appendix II 266

c. Tell them about artificial hatching of turtle eggs and caring for the baby turtles before releasing to the sea.

d. Ask them to catch a giant leatherback turtle and put it in a cage and take good cart of it.

5. A teacher wishes to teach his students the effects of excessive logging in forests around the country. Which is the most effective way of doing this?

a. Ask students to read from the textbook.

b. Ask students to interview government officials assigned to take care of the forest.

c. Take students to a logged over forest.

d. Ask students to clip news about logging from the local dailies.

6. Oil has just been discovered off the coast and people are excited over its economic implications. As a teacher how would you handle the event?

(1) Prepare a scicncc lesson on oil.

(11) Ignore the oil discovery.

(111) Write a letter of protest to the government asking it to stop the oil exploration.

(I”) Discuss the positive and negative aspects of oil production, refineries and uses of oil.

a. (I) and (II) b. (I) and (III)

c. (II) and (III) d. (I) and (IV)

7. The principal sources of air pollution in big cities are:

a. homes and industries

b. agriculture and industries

c. motor vehicles and industries

d. motor vehicles and homes

8. Which of the following human activities contribute the least to pollution?

a. digging a compost pit for garbage disposal

b. throwing waste into the river

c. burning off garbage

d. dumping waste on street pavements

9. One source of pollutant which may cause diseases like cholera is:

a. mine tailings b. domestic waste

c. industrial waste d. soil erosion

Sample Instruments for Assessing Students’ Achievement 267

10. Which of the following metal pollutants causes brain damage‘?

a. Copper b. Iron

c. Lead d. Calcium

e. Sodium

11. Heavy metals associated with the Minamata and Itai-Itai diseases are:

(1) Mercury

(11) Cadmium

(III) Sodium

(I”) Iron

(“) Lead

a. I and II only b. I, II and III

c. V only d. IV and”

e. All of the above

12. Which of the following activities produce noise most damaging to the ear?

a. Disco music and sound

b. Drilling on the concrete pavement of the street

c. Airplane llying over residential areas

d. Traffic noise in a busy street

e. Cheering of the crowd in a stadium

Use the following data on the population behaviour in Country A for items 13 - 14.

No. of pop. Births Deaths Emigration Immigration Total Year Population

1985 220 ooo 9oooo 30000 50000 1000000

1986 280 000 100000 10000 40 ooo 1210000

13. What is the National population growth rate in 1985?

a. 0.12 c. 0.14

b. 0.13 d. 0.15

Appendix II 268

14. What is the National population growth rate in 1986?

a. 0.15 c. 0.17

b. 0.16 d. 0.18

15. The following table indicates the sources of Electric Energy from 1977 to 1982 in Country B. (In million barrels of oil equivalent, MMBOE).

Oil 17.1 21.0 20.7 20.5 19.9 20.0

Total 20.9 25.7 28.1 31.0 32.0 34.0

Based on the above table, which of the following statements is true?

16. Below is a table of the Energy Demand from 1983 to 1985.

a) Coal has been increasingly used as fuel.

b) Geothermal energy has been used since 1979.

c) Oil is the major source of electric energy.

d) All of the above.

Source

Coal

Geothermal

Demand (in billion Kwh)

1983 1985

8.96 14.51

7.64 9.59

By how many per cent did the demand for coal increase in 1985’

a) 7.64 b) 14.51

c) 61.94 d) 86.25

e) 100.00

17. Which of the following sources of energy is renewable?

a) petroleum b) alcohol c) coal d) nuclear


18. Which of the following is/are characteristic(s) of a good fuel?

I. gives off much heat

II. inexpensive

III. burns completely

IV. renewable

a) I only.

c) I, II and III only.

e) all four.

b) I and II only.

d) I, II and IV only.

19. Which of the following sources of energy contributes the least to environmental problems?

a. solar c. petroleum

b. coal d. nuclear

Part B. Essay Test

Direction: Read the following value situations and answer the questions that follow after each account. Write your answers on a separate sheet.

1. Mr. Pedro complains that his well has stopped flowing because his neighbour, Mr. Joe, is pumping too much water from the same aquifer. Mr. Joe replied that there is no restriction to pumping of water and that the aquifer belongs to no one. It is a case of first come, first served. Do you agree with Mr. Joe? Why?

2. School A belongs to an elite class. During school breaks, the compound is always littered with left-over food such as apples,oranges, cakes, fritters, etc. In a nearby empty parking lot, street children usually huddle together, begging for food. How can the school change the bad habit of food wastage through a positive learning experience?

3. You have a piece of land planted with various trees which include mahogany. The Forest in the locality is being denuded at an alarming rate. Your family, being environmentally conscious, tries to preserve that area as Sanctuary for various flora and fauna. A member of the family falls very ill and all your financial resources are drained. For quite some time, one affluent neighbour has been offering a handsome price for all the mahogany found in your place. The money you would get is enough to tide the family needs over. Will you accept the offer of your neighbour? Explain your answer.

4. You and your friends collect rare kinds of shells as a hobby. Lately, you have been involved in an environmentally conscious group which promotes conservation of the natural resources. Suddenly, it dawns upon you that the activities your group are doing (the collection of the rare kinds of shell) are creating damage to the environment. How will you convince your friends to stop collecting rare shells?

5. Joseph uses chemical fertilizers and pesticides on his vegetable plot. Reynold uses organic fertilizers and does not apply pesticide on his vegetable plot. Joseph’s plot yielded more vegetables than that of Reynold? Does this mean that Joseph’s methods are better than Reynold’s? What factors must be considered in making a comparative assessment of the 2 methods?

6. You are the chairman of Barangay Malaya where a flourishing chemical plant employs about 500 bread winners. Your eldest son is the general manager. You received a directive from the provincial governor to close down the factory because of its inability to comply with the emission control standard. What would be your course of action? Explain the reason for your course of action.

7. You are the manager of a factory. You are to decide between using coal and using solar energy for the plant. With coal, you can raise your production target. However, coal causes pollution and is non-renewable. On the other hand, solar energy is cheap and inexhaustible. However, the technology is not yet fully developed and might slow down production. Which power source would you choose? What criteria would you use in decision making?

Part C. Attitude Test

Direction: Check (/) the letter which matches your extent of agreement or disagreement with each of the following statements.

SA: Strongly Agree

A: Agree

u: Neutral/Undecided

D: Disagree

SD: Strongly Disagree


1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

Overpopulation problems in certain areas can be solved by migration.

Over-population problems can be taught in formal school only.

Increase in crime rate is related with overpopulation.

Married people must have at least 4 children.

Family Planning is the most suitable method to decrease population growth.

Developing countries should have more people in order to increase their production.

Children are future investments; the more children a family has the better for the country.

Overpopulation may lead to poverty.

It is preferable to live in a city with modern facilities than in the countryside.

Water from the river should be purified before it is consumed.

Food additives are not hazardous to the health.

The use of fertilizers may affect human’s health.

For a healthy life, human should be concerned with the quality of air, water and food.

Hunting of seals and other polar animals for food and fur is alright for Eskimos.

Cutting down our forests will increase revenue for the country.

Mining brings more benefits to the local community than problems.

Air and water pollution are serious problems in many industrial countries.

Highly developed countries use more natural resources than the less developed ones.

19. Overpopulation is to be avoided to assure a reasonable standard of living for future generations.

20. Human’s utilization of natural resources is influenced by his culture.

21. Pollution is a problem associated with industrial countries as a price of progress.

’ 22. It is not necessary to clean the drain of rubbish because any way it will be washed away by rain.

Appendix II 272

23.

24.

25.

26.

27.

28.

29.

30.

31.

32.

The government is doing enough about cleaning up abandoned hazardous wastes.

Private citizens should be given a role in the choice of disposal site for hazardous waste.

The large sums of money spent on environmental pollution control could be put to better use on other things like new hospitals.

We are all responsible in one way or the other for the depletion of the ozone layer.

Water pollution is not a serious problem because 80% of the world’s surface is water.

“Water purifies itself by running two miles from the source of incoming waste” so there is no need to worry about water pollution.

An ordinary citizen can do a lot to prevent pollution of the environment.

Environmental education should be incorporated into the school curriculum.

The bad effects of air pollution are outweighed by the benefits of industrialization.

Community-based education on water and air pollution will help to reduce pollution problems.

Appendix Ill

Sample Instruments for Evaluating Training Programmes

A. Evaluating Training Outcomes

Part I. Multiple Choice

Directions: Choose the best answer for the following items. Write your answer on the sheet provided. Please do not write anything on the questionnaire.

1. What should be done to conserve natural resources?

a. do not use natural resources;

b. use natural resources wisely ;

C. restore natural resources;

d. replace worn-out resources.

2. Which of the following pollutants is degradable?

a. sewage;

b. pesticides;

C. radioactive wastes;

d. organic chemicals from industries.

. ___^ --

Appendix Ill 274

3. Which statement about water pollution is not correct?

a. the pollution of streams is more likely to occur where there are large numbers of people;

b. pollution is always a result of poverty;

C. the organic waste from domestic sewage and industrial wastes are oxygen demand- ing waste;

d. water purifies itself when allowed to run down an open stream.

4. Which method of solid waste disposal produces air pollution?

a. composting;

b. sanitary landfill;

c. dumping near waterways;

d. incineration/burning.

5. Which method will best decrease noise levels?

a. control noise at the source;

b. intercept noise between sound and receiver;

C. reduce sound at the receiver;

d. pass laws to reduce noise.

6. What causes the so-called “greenhouse effect”?

a. increased amount of carbon dioxide in the atmosphere which traps the heat radiated from the ground;

b. increased vegetation on the surface of the earth;

c. increased rate of melting of polar ice caps due to increased temperature of the atmosphere;

d. increased destruction of the ozone layer.

7. Increased carbon dioxide and other gases like methane and nitrogen oxides in the atmosphere is caused by:

a. extensive deforestation and burning of fossil fuels?

b. using sprays or propellants and refrigerants found in air conditioners, freezers, refrigerators?

c. breakdown of inorganic substances?

d. using chemical fertilizers?

Sample Instruments for Evaluating Training Programme 275

8. Adding too much chemical fertilizers into the soil may result in:

a. increased acidity of the soil;

b. making the pH of the soil neutral;

c. increased alkalinity of the soil;

d. rapid growth of plants.

9. Which of the following statements illustrates the law of conservation of matter and energy’?

I. energy from the sun is converted into chemical energy through photosynthesis and enables animals to perform different activities.

II. there is continuous supply of energy from the sun.

III. matter is returned back to the soil through decomposition.

IV. the amount of matter on earth is constant.

V. energy can assume several forms and transformation is 100% efficient.

a. I and IV only. b. I and II only

c. I, II and III d. all except 5

10. Which of the following statements is correct?

I. most pollutants are harmful to health.

II. air pollution is a global problem.

III. pollutants destroy buildings and the beauty of the environment.

IV. gaseous pollutants like sulphur oxides lead to acid rain.

a. I only b. I, III and IV

c. all d. II only

-II_- _.._ ~-. --. .-.-...-. _ __-.

Appendix Ill 276

11. Which of the following statements is NOT correct?

a. nitrogen oxides and unburned hydrocarbons react with sunlight to produce pollutants like ozone;

b. ozone is beneficial to plants and prevents the earth’s surface from absorbing too much ultraviolet rays from the sun;

C. ordinary smog caused by smoke and fog disappears as hot air rises;

d. photochemical smog remains longer in the troposphere and is manifested by a brown haze near the horizon.

12. Some direct causes of scarcity of fishes in ASEAN waters are attributed to the following:

a. use of fine sieve fish net;

b. dynamite fishing;

c. fish-poisoning by chemicals;

d. all of the above.

13. Eutrophication is caused by:

a. agricultural fertilizer run-off;

b. detergents (with alkyl phosphate);

C. industrial wastes;


14. ASEAN governments are trying to develop and conserve forests and wildlife sanctuaries. This action supports the idea that:

a. wildlife protected in parks and reservation areas is important for ecological balance;

b. forests and their wildlife support continuance of our cultural heritage;

c. forests and wildlife are sources of valuable information and scientific studies;



15. At the international level the best argument against the operation of Nuclear Power Plants is that:

a. the hot water released into the sea will kill marine life;

b. there is no place yet to dispose of radioactive spent fuel;

c. the plant may leak and emit radioactive substances;

d. the uranium fuel is expensive to process.

16. Mining degrades the environment because it removes minerals and rocks from land -

a. allowing the growth of unwanted vegetation;

b. polluting the land and water with mine wastes;

C. reducing the fertility of the soil;

d. causing land to sink due to the construction of tunnels.

17. Why does continued forest cutting shorten the usefulness of dams?

a. rivers are clogged;

b. tons of eroded soil are deposited in reservoirs;

C. water evaporates from reservoirs faster;

d. water in the reservoirs increases.

18. About 30 per cent of topsoil in many countries is eroded yearly. Which of the following should be done to control soil erosion?

a. build dikes;

b. improve irrigation system;

c. ban logging activities;

d. reforest mountain areas.

19. Garbage thrown into bodies of water kill fishes because the decaying garbage:

a. adds carbon dioxide to water;

b. gives off a bad smell;

C. removes the food eaten by fishes;

d. uses up oxygen needed by fishes in respiration.

Appendix Ill 278

20. A geothermal plant generates electricity from the energy of

a. burning coal;

b. flowing river;

C. steam from underground;

d. waterfalls.

21. In a technological world,which of the following human problems causes or aggravates the other three?

a. pollution;

b. over population;

C. safe waste disposal;

d. depletion of energy resources.

22. Mercury is a waste product of certain industries. It is often dumped into streams, rivers and oceans. Why is this a problem?

a. mercury is expensive;

b. mercury compounds are toxic;

C. mercury is a heavy metal;

d. mercury is not soluble in water.

23. Which of these best describes environmental issues?

a. everyone agrees on problems and solutions

b. there is controversy over nearly all problems and solutions

C. the problems can be solved by technology;

d. the problems must be solved by the government.

24. How can food be produced without harming the environment?

a. use organic fertilizer;

b. increase the use of pesticides;

c. plant one kind of vegetation on larger farms;

d. increase the use of inorganic ferilizer.


25. What is the best orientation towards nature to enable the survival of humans?

a. co-exist with nature by understanding and protecting it;

b. cultivate all suitable lands and eliminate all consumers that compete with humans and their animals;

C. maximize production with use of irrigation, pesticides, and inorganic fertilizers;

d. increase technological activities designed to control the environment.

26. Suppose your father owns a cement plant. The plant gives off pollutants of fine particles that cause lung diseases to employees and townspeople. Which of the following would you do?

a. put up a sign informing people of the dangers of inhaling the fine powder;

b. set aside a part of the employees’ salaries to pay for anti-pollution device;

c. put up an anti-pollution device;

d. wait for signs of bad effects of the polluted air before taking action.

27. As defined by the Unesco Tbilisi Conference, Environmental Education is characterized by:

a. a problem solving approach;

b. an interdisciplinary approach;

C. a community-based approach;


28. The science teacher can make science lessons value-oriented through the use of:

a. examples and applications;

b. existing degraded conditions;

c. local issues;


29. Which of the following characterizes environmental science education?

a. it is concerned with realistic situations;

b. it includes action as an integral component;

c. it involves the clarification of values;


-..- . . ___--__

Appendix Ill 280

30. Sustainable development implies that:

a. conservation and development can be mutually reinforcing;

b. some portions of the earth should be set aside as untouched reserves;

c. development models should meet the needs of the present without comprising the ability of future generations to meet their own needs;


Part II. Essay Test

Directions: Write your answers to the following items on a separate sheet of paper. Please be brief.

1. Please explain any of the following concepts:

a. eutrophication c. nuclear energy

b. food chain d. ozone depletion

2. Identify five possible behavioural objectives on the three domains of learning.

3. Discuss at least three environmental concepts.

4. Describe a motivational strategy.

5. Describe an instructional methodology.

6. Describe the evaluation methods.

Sample Instruments for Evaluarina Training Programme 281 -

B. Evaluating Training Programme

Programme:

Dates:

Programme Content (circle your answer)

1.

2.

3.

4.

5.

Was the programme content as organized (sequence of activities) supportive of the expected outputs?

Can you relate the situations in the lectures to your own job?

Did you find participation in the application exercises beneficial?

Are the activities congruent with the outlined programme content?

How useful were the visual aids in elucidating lecture topics? (OHP, slides, etc.)

Overall Programme

6. How applicable is your learning in this programme to your own job?

7. How frequently were you challenged by the content and the exercises?

8. To what degree did you feel that the content and exercises were relevant to your job?

Difficult to understand

1 2

Seldom

1 2

Seldom

1 2

Not clear

1 2

Of no use

1 2

Easy to understand

4 5

Consistently

4 5

Consistently

4 5

Very clear

4 5

Very useful

4 5

Not applicable Very applicable

1 2 3 4 5

Seldom Consistently

1 2 3 4 5

Not relevant Very relevant

1 2 3 4 5

9. How would you rate the physical facilities in which the programme was held?

Presentation

10. How would you describe the lecturers’ knowledge of the subject matter?

11. How did you find the lecturers’ style of delivery?

12. Were the concepts, principles and techniques explained in an understandable manner?

13. Did the lecturers invite and encourage individual participation?

14. Did the lecturers maintain control of the discussion and work groups?

15. Did the lecturers use visual aids for reinforcement of discussion points?

16. Did the lecturers hold your interest?

Appendix III 282

Poor

1

Limited

1

Uninteresting

1 2

Seldom Understandable

1 2

Seldom

1 2

Seldom

1 2

Seldom

1 2

Seldom

1 2

Exceptional

4 5

Extensive

4 5

Dynamic

4 5

Consistently understandable

4 5

Consistently

4 5

Consistently

4 5

Consistently

4 5

Consistently

4 5

17. Please comment on any question (overall programme, programme content or presentation) to which you gave a rating of 1.

Question No. Comments

18. Do you have any additional comments regarding programme or presentation strengths and weaknesses?


Participant Profiles

Your answer to the following questions are for our research purposes only. You may sign or not, as you wish.

A. Your position title

B. Educational level

C. Name and address of school connected

D. Years in teaching

E. Signature

C. Evaluating Peer Teaching Demonstration

Teacher’s Name:

Topic Taught:

Please rate the teacher on the following skills by checking the column that matches your judgement. Use the scale below.

E = Excellent G = Good

VG = Very Good P = Poor

A. Rate the teacher’s ability to:

1.

2.

3.

4.

5.

6.

7.

Get the learner’s interest from the start.

Use appropriate examples/ illustrations to clarify concepts.

Relate the lesson with environmental issues/ problems.

Ask interesting/ challenging questions.

Make abstract concepts concrete.

Use appropriate visual aids.

Elicit students’ views and ideas.

--_l__- .-. . ..---__

Appendix III 284

8. Make use of student ideas.

9. Sustain students’ interest throughout the lesson.

10. Lead students to draw out generalizations.

11. Integrate values into the lesson.

12. Use appropriate strategies for evaluating students’ learning.

6.

1. What environmetal issues were tied up with the lesson?

2. What specific values did the teacher integrate in the lesson?

3. What specific strategy was used in the lesson?

C. Comments:

Points to focus on on:

A. Role Playing

1. Relevance of the situation to the lesson

2. Characterization by the actors

3. Values/attitudes projected

4. Variety in values/attitudes which different learners can identify with.


B. Discussion

1. Extent of participation of group members

2. Elicitation of varied viewpoints

3. Respect Car one another’s viewpoint

C. Laboratory Techniques

1. Safety measures and precautions taken

2. Laboratory skills

3. Sequence of procedures

4. Generalizations arrived at

Appendix IV

Worksheets for Organizing Field Investigations

A. Ecosystem Structure and Function

1. Topic: Vegetation Structure of a Grassland.

2. Objectives: To characterize the vegetation structure of a grassland ecosystem using two techniques:

l Floristic methods which focus on the species structure of the vegetation; and

l Physiognomic methods which describe the physical structure of the vegetation in terms of the life-forms present.

3. Resources Needed:

l Transect lines;

l One-metre-square quadrats;

l Plastic bags with labels;

0 Plant cutters;

l Reading material: Section on Raunkaier’s life-forms in the paper “Ecosystem Structure and Function”;

l Reference material: book on taxonomy of Philippine weeds and grasses.

4. Strategy (1.5-hour Session):

l Explain in 5-10 minutes the floristic and physiognomic methods of vegetation description and analysis;

l Divide the class into two groups. Equip each with a transect line and three quadrats;

l Visit a nearby grassland habitat;

l Each group will lay down a transect line across the field. One group may set up a north-to-south and the other an east-to-west transect line;

l At 10 or 15 metre intervals lay down a quadrat. Thus, each group will have three quadrats, each of which will be 10 or 15 metres away from one another;

Appendix IV 288

. Examine each quadrat in terms of the different plant species within the one metre-square area in terms of:

- Species list that includes the taxonomic names of all the species within the quadrat. (In case the identification cannot be done in situ, place it in a plastic bag and label it as Herb or Grass 1,2 or 3 etc. from Quadrat 1,2 or 3 as the case may be. Bring this to the laboratory for identification using a taxonomic reference book.)

- Life-forms, using Raunkaier’s scheme.

- Plant cover that would estimate the relative importance of each species or life-form in each quadrat. Plant cover is usually taken as the area covered by the aerial parts of the plant or as the basal area occupied by each plant, depending on the convenience or facility of the worker. The plant cover for each species or life-form is expressed as percentage cover, i.e. per cent of the one metre-square area covered by the plant. When aerial parts overlap, the percentage covers of all the species or life-forms in each quadrat may exceed 100 per cent. This does not happen if the basal area of each plant is used.

- Density, which is a measure of the number of individuals of a particular species or life-form per unit area, which in this case is the one metre-square of the quadrat.

- Frequency or the probability of a particular species or life-form being encountered and hence listed in any given quadrat. For instance, if a particular species occurs in all the three quadrats its frequency is taken as 100 per cent.

l Along the edges or limits of the quadrat frame may be found plants whose other parts also extend beyond the quadrat. These edge plants may or may not be included in the listing. But once the worker decides to consider them as a part of a sampled quadrat, then this should also be done in the other quadrats as a matter of consistency;

l After examining the quadrats, the groups will return to the laboratory to consolidate their data and, should there be enough time, to identify plant specimens;

l Fill up the Quadrat Record Sheets using the floristic and physiognomic data from each quadrat;

l The average data on plant cover, density and frequency for each species or life-form from the three quadrats will also be tilled into a Quadrat Record Sheet.

Worksheets for Organizing Field Investigations 289

Quadrat Record Sheet: Floristic Method

Site:

Date: Quadrat Size:

Transect Line:

Name of observer:

Quadrat Number:

Species Percent Cover

Density (Individuals per Square Meter)

Percent Frequency

-______ --.. ---- -_._.-

Appendix IV 290

Quadrat Record Sheet: Physiognomic Method

Site:

Date:

Quadrat Size:

Transect Line:

Name of observer:

Quadrat Number:

Raunkaeir’s Percent Life-Forms Cover

Density (Individuals per Square Meter)

Percent Frequency


B. Energy Flow and Nutrient Cycles in the Biosphere

1. Topic: Net Primary Production in a Grassland

2. Objective: To describe a technique for estimating net primary production in a grassland using the Wiegert-Evans method. (This method needs at least two sampling periods).

3. Resources Needed:

l Wooden or bamboo stakes;

l Nylon string;

l Trowels;

l Plastic bags;

l Pan balances;

0 Plant cutters;

l Reference material: Wiegert, R.G. and F.C. Evans, 1964. Primaryproduc&r and the dimppearmce of dead vegetation on an old jield in south-eastern Michigan. Ecology 45:49-63.

4. Strategy (1.5 hour-Session):

l Explain in 5-10 minutes the Wiegert-Evans method of measuring net primary production in a terrestrial habitat.

l Divide the class into five groups. Equip each with a plant cutter, 12 stakes, nylon string, a trowel and plastic bags. Bring them to a nearby grassland.

l Each group will select three adjacent sites that are quite similar in plant density and species composition. Construct a 0.1 metre-square plot in each site with the use of stakes and nylon string to delimit the plot’s boundaries. Label the plots as 1,2 and 3.

l From Plot 1, the living and dead plant materials will be collected. All the dead material or litter will be gathered and placed in a plastic bag. The living parts above the ground will be clipped off and placed in another plastic bag. The soil will be scooped out to a depth of around 20 centimetres or down to where the roots penetrate and placed in a third plastic bag.

l From Plot 2, all of the living plant material above the ground will be cut off and placed in another plastic bag. The dead plant material will be left. No soil sample will be taken from this plot. Plot 2 will provide an estimate of the rate of disappearance of dead shoot material during the measurement period.

l Plot 3 will be left intact or undisturbed.

l In the second measurement period, the dead plant material from Plot 2 will be collected into a plastic bag. All the living material, dead plant parts or litter, and soil down to a depth of 20 centimetres will be collected in different plastic bags. (This, however, cannot be performed during the course.)

l The materials collected from the plots will be brought to the laboratory. The root material from the soil samples will be obtained by repeated washings and flotation.

Appendix IV 292

. All the plant material should be placed in the oven at 100 degrees C until constant weights are obtained. (Since this cannot be done here, the fresh weights will be taken instead - but this is not the actual practice: the dry matter should be used in production measurements).

o The dry weights will be taken and recorded in a Standing Crop Table. (In this exercise, however, the fresh weights will be entered just for familiarization purposes.)

l The following calculations can be accomplished only after a second measurement has been done:

- The rate of disappearance of plant litter or dead shoot material from the undisturbed Plot 3 (R) may be estimated from the weights of the litter from Plot 1 (Wc), which serves as the initial reading, and from Plot 2 (WI) by the equation:

R (in grams/gram/day) = Loge (W()/WPVlPV)

t where t is the length of the production period or the number of days from the first to the second measurement.

The quantity of dead material disappearing from Plot 3 (x) during the production period will then be determined from the amount of dead material at the beginning (au) and end (al) of the production period and the rate of disappearance of dead material as measured in 4.11.1. The formula to be used is:

X (in grams per plot) = VR,

where au is the weight of plant litter or dead shoots from Plot 1; al is the weight of the litter or dead shoots from Plot 3.

The death of living shoot material (d) during the production period will then be calculated from the change or difference in the weight of dead material (x) and the quantity of dead material disappearing during the production period (al- au). The following equation will be used:

d (in grams per plot) = x + (al- au)

- The net production of shoot material during the production period will be estimated from the change in the weight of living shoot material during the period (bl-bc) and the weight of shoot death, using the formula:

y (in grams per plot) = (bl- bo) + d

- where bo is the weight of living shoot material from Plot 1; and bl is the weight of living shoot material from Plot 3.


l The net production of shoot material (y) will then be combined with the increase in root biomass during the production period to give an estimate of total net production (TNP, in grams dry weight of biomass per plot), as shown in the following equation:

TNP (in grams dry weight of biomass per plot) = y + (el- eo)

where el is the root biomass from Plot 3; and eg is the root biomass from Plot 1.

l Total net production may also be expressed in gram-calories of energy if estimates of the caloric value of the different plant materials weighed can be obtained. The area of plot for primary production may be extrapolated into square metres, hence grams per square metre instead of per plot will be used. The data obtained from the different equations and formulae above may also be recorded in a Table on Net Primary Production.

Plot Site:

Standing Crop Table

Plot Size:

Date of Measurement:

Name of observer:

Plot Number Living Shoot Material Dead Shoot Material Total Root Material

I Disappear ante Rate of Dead Material

Plot Number

P)

Appendix IV 294

Table of Net Primary Production

Disappear ante of Dead

Material during

Production Period (X)

Change in Standing Crop of Living Shoots

(bl - bg)

ncrease in Root

Biomass

(a- eo)

Total Net Production

during Period

(grams per plot)

Total Net Production

during Period (gram

calories per square

meter)


C. Environmental Impact Assessment

Tasks

A. Read the background paper on the proposed project.

Determine:

1. the most probable environmental impact

2. whether or not the project should be implemented

B. Assume a scenario where the project will be allowed

1. Propose solution (s) to the effluent/ emission problems generated by this industry/ factory.

2. Examine the pollution control alternatives and select the most cost effective solution.

C. Suggest how this activity could be used in science/ environmental education classes.

Environmental Setting

Biogeophysical Characteristics

The observed general characteristics of the site are its flatness, its being an alluvial plain and the absence of rocks. The general vicinity is basically agricultural, with secondary growth vegetation. Fruit-bearing trees like mango, santol, banana and star apple are planted within the residentialbarangay areas. The site is surrounded by ricefields.

The nearest surface water of consequence is classified as class C river and is about 600 metres north of the project area.

A sixty (60) foot deepwell was recently drilled at the site and yielded potable water.

The problem of air pollution within the project area has not surfaced before and therefore no historical data is available.

Socio-Economic Characteristics

The project area and general vicinity are primarily agricultural. Built-up areas are predominantly residential. Size of cultivated land per farmer ranges from 1 to 3 hectares. Such plots have been generally farmed from 1 to 10 years although some have been cultivated for as long as 50 years. Rice is the most commonly planted crop during the rainy season. Yield is normally 200 cavans/hectare of the fertilized field. Only a small percentage of the rice planted is for family consumption; most is sold. A major problem encountered in farming is lack of capital and absence of access to credit. The production cost per hectare can reach as high as P/10,000. The average selling price this year is P/4 per kilo for wagwag and P/3.70 per kilo for other varieties.

A. Demography

Municipal population is about 52,730with a family population of8735 with a total average size of six members. Fifty-eight per cent (58%) comprise the working age group, ap-

Appendix IV 296

proximately 15-64 years old while forty-two per cent (42%) compose the economically dependent population.

The three major causes of morbidity are trichuriasis, ascariasis and bronchitis while the leading causes of mortality are broncho-pneumonia, heart diseases and pulmonary tuber- culosis.

The project site vicinity is under the jurisdication of three barangays, data on which are as follows:

Barangay #1

Area - 168.36 hectares Population - Total number of families - 20 Average family size - 5 to 6 members

Barangay #2

Area - 112.75 hectares Population - Total numer of families - 23 Average family size - 5 members

Barangay #3

Area - 165.82 hectares Population - Total number of families - 28 Average family size - 5 members

Table 1. Occupation

Total 61 80 80 77


Table 2. Skills

Data on water facilities show that thirty-three per cent (33%) of the population rely on deep wells as their main source of water supply while only one per cent (1%) use shallow wells. The rest did not indicate their water source.

Toilet facilities are either water sealed (30%) or septic tanks (11%). Open drainage is more commonly used.

Garbage disposal is by burning (36%), dumping (21%) and burying (14%). Overall cleanliness is rated good by 59%, fair by 22% and poor by 22%.

B. Man-made Facilities and Activities

These refer only to the feeder roads and other ordinary facilities and activities related to the demand of the sitios and barrios.

C. Aesthetics and Human Interests

Except for the simple rural and peaceful environment, the locality offers nothing more in the field of aesthetics, and human interests.

D. Cultural Status

The barrio people are mostly farmers and chicken raisers who depend on their crops and poultry income. As mentioned, they live a simple lifestyle typical of rural areas.

--

Appendix IV 298

E. Recreation

Simple rural life takes away the urgent need for recreation. To the barangay folks, huddling while planting crops or doing the laundry in a river is already recreation. Drinking sessions among men, however, are a popular past time. There are no man-made resorts in the locality.

Description of the Proposed Project

Location

The plant compound will use up approximately 10.2 hectares. The area is surrounded by ricefields and several poultry farms. The northside section of the proposed compound is traversed by a river about 600 metres from the plant (current classification is Class C).

Type of Industry

Light Metal Industry

Production Capacity - one (1) metric ton per day Some of the raw materials used are coal, coke, iron, limestone, foundry returns, metal turnings, alloys, carbon additives, fluxes, and sand additives.

Main Product Line - Electric Range (capacity of 500 to 2000 watts)

Project Life Span Plant Operation -

Major elements flowchart:

- 25 years Eight (8) hours per shift/day at six (6) days a week

of the manufacturing process are provided in the following

. 1 Heat Treatment /

I

Finishing

:

Production

I Cleaning I


Characteristics of Wastewater to be discharged

a. Industrial Wastewater discharge:

Maximum Flowrate - 35 m3/day

Average Flowrate - 25 m3/day

Minimum Flowrate - 15 m3/day

Parameters

Colour Units (apparent colour) Turbidity, ppm SiO2 Settleable matter ml/L PH Total solids, mg/L. Total dissolved solids, mg/L Suspended Solids, mg/L

Fe, mg/L Cu, mg/L Zn, mg/L Ni, mg/L Mn, mgL

b. Domestic Wastewater (Plant Staff/Personnel)

Average Volume of Discharge

B.O.D. Suspended Solids PH

Characteristics

Concentrations

800 500

4 1.3 - 3.8

5000 4100 900 129 0.01 0.1

120.1 1.80

2.0 m3/day

200 mg/L 240 mg/L 6.7 - 8.8

Source of Air Pollution

a. Foundry Shop

Cupola Furnace

Specifications:

Charging door area =

Tuyere Air - 1810 cfm -

maximum’ gas temperature at cupola outlet - 2000 degrees F.

32 inch ID cupola maximum incineration temperature to be maintained at cupola outlet 1200 degrees F,

4.5 ft 2 inches;

Dust loading ranging from 1.10 to 1.32 gr/scf in the 20 to 44 microns.

b. Assumptions

The whole facility is a closely coupled unit from the cupola to the evaporated cooling chamber and the insulated duct between the evaporative cooling chamber.

Appendix IV 300

Other Relevant Information

A 20,000-head poultry farm and cockpit are located about 100 metres from the proposed site.

Earnings from the cockpit are approximately P 30,000 per month and from the poultry sales P 90,000 per month.

A 15,000-head piggery is also located about 500-600 metres from the proposed plant. Income derived from this is about P 67,000 per month.

Notes:

1. It should be stressed that there is no single answer to this casework although some options may be preferable to others.

2. In order to assist the participants to evaluate the alternatives, cost data for the relevant equipment, chemicals, electricity, drainage and installation are given. For the purpose of comparing alternative schemes, it is necessary to consider the total cost.

3. Assumptions should be made in instances where there are gaps.

D. Water Ecosystem

Objectives

1. To predict probable physical, ecological, and socio-economic consequences of a particular development activity; and,

2. To identify possible alternatives to mitigate or prevent the effects of environmental impacts of such development activities on man and the natural ecosystems.

Materials

A list of development activities will be provided including information on some possible physical, ecological, and socio-economic consequences of these activities.

Methodology

1. Identify a particular development activity in the list provided.

2. List the probable benefits that may be derived from the identified development activity.

3. State the probable economic costs that may be incurred in pursuing the identified development activity.

4. Describe the probable environmental costs that may be expended in pursuing the identified development activity. By referring to the list provided, you should be able to:


a. Identify specific physical changes associated with the development activity you have chosen; and,

b. Predict the probable ecological consequences that may be brought about by such alteration/modification of the physical environment of the impact area, and describe in some ways whether these effects:

l will be restricted to a particular species population or will grossly affect the community in the target ecosystem;

l will be directly or indirectly affecting a species population or community;

l will be immediately felt by a species population or community or may take place at a later time.

5. Name and describe possible alternatives that may most likely minimize or mitigate the probable environmental impacts of the identified development activity. State the probability of such alternatives being considered to decide whether such development activity ought to be done or not. Justify your position on the chosen alternative(s).

Evaluation:

A class discussion will be held to evaluate the assessment made by students/groups on the environmental impacts of development activities and the mitigating measures proposed. Some lead questions may be raised to initiate such discussion.

a. Were all probable impacts identified?

b. Were the effects of environmental impacts of development amenable to quantification? Can these be monetized?

c. How feasible were the mitigating measures proposed?

d. Should all development activities be subjected to an environmental impact assessment?

E. Energy and Mineral Resources Degradation

This part serves two purposes: (a) evaluation of the trainee’s understanding of the subject, and (b) illustration of the practical application of the concepts and skills presented in the paper.

The problems or exercises given below must be addressed using the reference materials provided for in this module, in addition to whatever stock knowledge the students have. These problems are intended to sharpen the understanding of the students of the environmental effects of mining, including their analysis and evaluation. They also draw attention to some of the common pitfalls that environmental regulators meet in dealing with mining.

1. Each student should list down the three most important mining operations in your locality or country with which you are familiar. Under each of them tabulate the social and economic benefits and costs that you can attribute. Examine the list carefully and weigh the benefits against the cost to determine intuitively if, on balance, it is for the good of society to allow such mining operations. What conclusions do you arrive at? Is this a satisfactory method

Appendix IV 302

of decision making? What problems did you encounter? Explain or make suggestions on how to improve the method.

2. Constitute yourselves into groups of about five members each. For each group prepare a list of at most 10 criteria (benefits and costs) which can be used to judge whether a project (regulation or policy) is beneficial or not, using the Kaldor-Hicks criterion, as described in the text. The group must be able to agree after discussion on the final list. Then assign weights (proxy for pecuniary measure) to each criterion, the sum of which should not exceed 100, to reflect the relative importance of each. Then consider that the possible score under each criterion for each mineral project ranges between zero and five.

To get the weighted score for each project multiply the weight of each criterion by the corresponding score, then take the sum of the weighted scores for the project. To get the weighted average score, divide the weighted sum by 100. This weighted score can be used to rank projects. The higher the weighted score the better the project is. Do your calculations in table form.

3. For each group select by consensus five mining operations you are familiar with which you will compare using their weighted average scores. For each project calculate the weighted average scores. Arrange the projects in a table according to decreasing value of their average weighted scores. Which project is most beneficial and which is the least? On the basis of your personal knowledge about the mining projects, do you agree with the ranking just arrived at? Explain. Suggest some ways by which the ranking decision can be improved.

4. For each group select a representative to a General Class Committee which will draft the set of criteria and their weights for evaluating mineral projects. The Committee shall apply those criteria in evaluating mineral-related projects which the group shall agree on as most familiar or important. Ideally, the Committee must present its findings to the class. Discuss the advantages and disadvantages of this method of decision making.

5. Prepare a list of forms or methods of reclaiming mined out areas, mine wastes, etc. Comment on whether they are satisfactory or if such methods can lessen the environmental costs of mining. Can you envision a reclamation scheme in which the reclaimed, mined out areas and wastes may become more desirable than the original unmined land? Explain. Should such reclamation schemes be the goal of environmental policies related to mining? What objections do you think will be raised against such an idea? Are such objectives reasonable? Explain.

6. In the Philippines fines or charges have been imposed in proportion to the amount of tailings dumped by the mining firms into the water system. Such fines are collected by the government and channelled to the general fund of the national treasury. Some officials concluded that “the market mechanism does not work in controlling pollution” as evidenced by the complaints of fishermen, farmers and local politicians and the continued siltation of river beds, irrigation canals and rice paddies downstream. Evaluate the preceding comment and explain why the economic mechanism does not seem to work under the situation. Are there flaws in the regulation or its implementation? Explain how this market method of controlling siltation can be improved to achieve the desired objective.

7. Suppose a shallow-seated large gold deposit is situated under a lush virgin forest in a government forest reservation near the seashore where there are coral reefs rich in fish. A feasibility study shows that 2000 hectares of forest cover will be affected in 30 years; erosion is likely to take place in the affected area along with possible destruction of a three km. stretch of coral reef which may decrease fish catch by as much as 20 per cent compared to the period


before mining. However, it is estimated that about 30 million ounces of gold (assume $36O/oz) will be produced during the 30 year mining life, with expected profit of 40 per cent. Direct employment in the mine is estimated at 5000 persons; government royalty is 5 per cent of gross production; income tax is 30 per cent of net profit; domestic purchases of goods and services comprise 60 per cent of total costs, which include infrastructure and maintainance. Suppose the President constituted a commission to study whether the mining operation should be allowed or not, and you are appointed the commission chairman. Will you recommend the mining operation proceeds based on existing information? How will you go about arriving at a decision? Outline the procedure you intend to follow, including the information you will require to arrive at a decision. Do you think the decision you are going to make has an important bearing on national interest? Why? Can you venture making a tentative “go” recommendation based on the given information? Explain.

F. Community-based Environmental Education

Objective:

To design an appropriate student activity or project for an environmental problem/ issue in a given community.

Materials:

. transparency sheet

0 pentel pen

Procedure:

1. Form yourselves into groups of 2-5 participants according to your area of specializa- tion.

,

2. Select a community with needs and resources known to one or more numbers of the group.

3. Identify an environmental problem or issue in the community.

4. Briefly describe an appropriate student project/ activity or outline the procedure of project/ activity addressing the environmental problem/ issue.

5. List the underlying science concepts, skills and values of the project.

6. Fill in the form (next page) on a transparency sheet and present your project/ activity to other participants.

7. Revise your project/ activity based on the suggestions of other participants.

8. Reproduce your write-up and distributed copies of other participants.

Appendix IV 304

Sample 1

Country

Grade Level

Estimated Time to Complete Activity:

Community Need

Physics Concepts

Scientific Skills

Scientific Values

Community Resources

Materials Needed

Objectives:

Philippines

Grade 10 (Age 16)

7 hours (4 class hours)

Minimizing noise pollution

Musical sound and noise, loudness, intensity, amplitude, quality, and noise pollution.

Observing and estimating waveforms, interview skills, and comparing.

Patience, cooperation, honesty in gathering data, and concern for public welfare.

Trains and railway station, busy streets, business establishments, TV repair shop.

Tape recorder, blank tape, oscilloscope, cartolina, pentel pen

At the end of the activity, the students should be able to:

1. Identify the sources of noise in the community;

2. Record the sound/noise produced from different sources in the community;

3. Compare the waveforms of musical sounds and noise;

4. Explain the health hazards of noise pollution;

5. Discuss ways of eliminating or mini&zing noise pollution in the community; and 6. disseminate to community information about health hazards of noise pollution and ways of minimizing it.

Teaching Hints:

1. This activity is best taken after the properties of sound waves are discussed in the class.

2. Steps 1 to 3 of the procedure may be done outside class hours.

3. Askstudents to record soundsonlyon the noisy places in thecommunitysuch as streets, railway station, market, business establishments, and inside publicvehicles with stereo.

4. Divide the class into groups of 4-5 students. Assign each group to monitor only one area. Step 1 should be done before the groups are given their particular assignment.

5. If there is no oscilloscope in the school, bring the tape to a TV repair shop.

6. Post the reproduced waveforms on the blackboard.


7. Present the decibel scale in class (see Physics In Your Environment, p. 140) after discussing question Q6.

Pre-Activity Discussion:

Motivate the class by asking students about the latest popular music. Ask them why they like music. Then ask their opinion on weather the ban of stereo in public vehicles should be strictly enforced. Lead the discussion to the sources of noise in their community.

Discuss the particular questions they should ask a doctor on the hazards of noise pollution. Remind them to be courteous when interviewing a person. Remind them to be careful when monitoring busy streets.

Procedure:

1. Make an observation tour around the community. Identify the places or areas in the community that are relatively noisy. Find out the sources of the noise either by observing or by interviewing residents in the area.

2. Using a casette recorder and a blank tape, record the noise in the area you are assigned for five minutes at different times of the day. Indicate the area, source(s) of noise/sound, and time of the day the sound/noise being recorded in the tape. Make sure the volume setting of the recorder is the same everytime you record.

3. Record different types of musical sounds.

4. Replay the different recorded sounds in class and observe their waveforms on the oscilloscope. Copy the waveforms on a piece of paper.

5. Observe the amplitude and frequency of the waves.

l Describe and compare the waves of musical sounds and noise.

l Which sounds were the loudest? Which sound waves have the biggest amplitude? the smallest amplitude?

l Which sound waves have the highest frequency? the lowest frequency?

l At what time of the day in a certain area, is the noise loudest?

l Which sounds were most unpleasant?

l What characteristics distinguish noise from musical sound?

l Interview a medical doctor about the health hazards of noise pollution and report summarized results of interview in class.

7. Suggest ways of minimizing noise pollution in the community.

8. Disseminate this information to the community by means of posters. Include in the posters the health hazards of noise pollution.

9. Place the posters in the barangay center, market, and other places where many people go to.

Post-Activity Discussion:

Discuss the problems encountered by students in the activity. Elicit suggestions from them on how to overcome the problems. Ask students how this activity can be improved. Instruct the students to observe the effect of their posters on noise pollution. Ask students to report their observations one week later. After students report on the effect, if any, of posters on noise pollution, discuss the limitations of posters, as well as students’ observations. Further actions may be discussed. These actions need not be implemented, especially if no additional physics concepts are learned. It suffices for students to realize the adequacy or inadequacy of one set of actions.

Sample 2

Title

Location

Grade Level

Age of Students

Estimated Time to complete Activity :

Environmental Problem/Issue :

Science Concepts

Scientific Skills

Scientific Values

Community Resource(s)

Other Materials Needed

Brief Description of Activity:

Save Electricity

Kampong Air, “Water Village”

Lower Secondary

11-13 years

2 weeks

Saving on Household Electricity

Energy; Conservation; Electricity as a Source of Energy; Watt; Ampere; Voltage; Power.

Reading meters; calculating power.

Prudent use of energy; responsibility; concern for others; civic-mindedness; awareness.

schoolgrounds; human resources; duplicating machine.

pencil; crayons; paper; notebooks.

1. Students learn/review concepts and skills in calculating electrical power consumption and the charges for the same. They also learn how to read meters.

2. Students do a simple research on the average electrical consumption of a family of four based on hypothetical data such as the number of appliances used and duration of use, and finally come up with a standard charge for such a family.

l Collect technical data of the electrical appliances from manuals, shops, or the manufacturers.

l Collect data on how to calculate the charges from the district electric company.


l Interview an electrician or an officer from the electrical company on how to compute electrical charges.

l Analyze data and tabulate results in a form most easily understandable to the students.

3. Prepare pamphlets and posters on how to use electrical appliances wisely so as to conserve electricity.

4. Students launch an Energy Conservation Campaign by visiting homes and interviewing residents. The interviewee’s electricity bill will be compared with the standard electricity bill which the students have calculated. The students will talk about good habits which help to conserve energy in the use of electrical appliances. The other aspect of the Energy Conservation Campaign will entail putting up posters on bulletin boardsand in public places, townhalls, schools, market places, bus stations, etc., (after prior permission from authorities is granted.)

Sample 3

Title

Community

Grade Level/Age of Students :


Environmental Problem/Issue :

Science Concepts

Scientific Skills

Scientific Value

Community Resources



Green is Clean and Beautiful.

Metropolitan

Lower Secondary/l4 years old.

2 weeks.

To help purify the air by planting green areas.

Green plants give off oxygen and take in carbon dioxide during the process of photosynthesis.

Observation; communicating; surveying; making decisions; planning; designing.

Appreciation of nature; sense of clean living; learning about cooperation, patience, hard work and sense of service to society.

Forestry Department.; Horticulture Department.

Seeds; plants/trees; tools and equipment for gardening and planting; fertilizers.

1. Discussion in the classroom to decide which area to concentrate on.

2. Conduct a survey in the district to find out about the extent of the problem in the area.

3. Seek the advice of Bangkok Metropolitan Authority in designing the students’work plan and obtaining the materials necessary to carry out the project.

Appendix IV 308

4. Campaign on the issue by putting up banners and posters/distributing leaflets to encourage the community to beautify their surroundings.

5. Select 10 households near the school to carry out the mini-project.

6. Students working in groups will start planting in the immediate vicinity of the school as well as in the compounds of about 10 households.

7. Students will see to it that the plants are growing well and gradually extend their programme to the other houses in the community.

8. There will be a “Tree Planting Day” when everyone will be out to plant trees to beautify the environment.

Sample 4

Title .

Grade Level/Age of Students :


Environmental Problem/ Issue :

Science Concepts

Scientific Skills

Scientific Values

Community Resources


Procedure:

Population Growth

Grade 8, (16 years).

1 week

Population Growth in Bangkhen.

Birth Rate; Death Rate; Migration; Carrying Capacity; Exponential Growth; Population Dynamics and Family Planning.

Collecting data; calculating and comparing.

Patience; cooperation; honesty in gathering data; and concern for public welfare.

Statistics Department.

Data from Statistics Department; poster.

1.

2.

3.

4.

5.

6.

Students collect raw data on: birth rate; death rate; migration; production of food; income and poverty; and land space for a five year period (1983-1988) from the Statistics Department in Bangkhen.

Students calculate growth rate and carrying capacity and plot a graph and compare the growth rate for each year.

Compare the growth rate with that in another place in Thailand.

Collect data from hospital/clinic on Applications of Family Planning in Bangkhen.

Students discuss the growth rate and make conclusions and suggestions on the growth rate related to food, land space, pollution, water supply, family planning.

Disseminate this information to the community by means of a poster. Include information on Family Planning in the poster.


Sample 5

Group

Title

Grade Level/ Age of Students

Estimated Time to complete

Environmental Problem/ Issue

Science Concepts

Scientific Skills

Scientific Values

Community Resource(s)


: Natural Resources

: Conservation of Marine Turtles

: 1st year Secondary School.

: l-2 weeks

: Threatened extinction

: Life Cycle; Conservation of Turtles; Marine Pollution; Feeding Habits; and Food Chain.

: Observation; interviewing; data collection; and predicting.

: Concern for wildlife and conservation; and community cooperation.

: Beach resort; fishing boats; hotels/ houses along the beach.

: Posters; local mass media; tape recorder; blank tape; and appeal letters.


1. Grouping of students: Collecting data/information; writing letters; interviewing; making posters;

2. Writing Letters. Students discuss with village folk the benefits of conserving the turtle and request the community to send letters to the newspaper, mass media and the authorities to promote turtle conservation, reduce pollution of the sea and improve the attitude of the fishermen to turtle survival.

3. Interview: Local people, tourists, government officials, the people who work in the hotel, people who sell turtle eggs. The aim is to highlight the declining number of turtles coming to lay eggs and the unnecessary killing of turtles caused by fishermen and waste such as plastic bags.

4. Collection of Data and Information. Students are asked tocollect data and information from libraries, newspaper cuttings, brochures, etc. This will be used in writing letters to the mass media, the authorities, the village chiefs, hoteliers and tourist agencies stressing:

l The value of more turtles coming to shore e.g. more tourists will come.

l The devastation caused by human consumption of turtle eggs or turtles and the need for a ban or punitive laws.

Appendix IV 310

l The need for pollution prevention measures e.g. less littering on beaches, seas and rivers.

5. Making Posters. Groups are assigned to make attractive posters to be posted on trees on the beach, handbills with slogans for distribution and pasting at strategic places.

Sample 6

Title

Age of Students

Estimated Time

Environmental Problem

Science Concepts

Scientific Skills

Scientific Values

Community Resources

Description of Activity:

: Water Pollution.

* . 13-14 years old.

: 1 week

: Pollution in Kuantan River.

: Unmanaged effluents from factories result in water pollution which is hazardous to aquatic life.

: Observation and comparison; recording of data; use of scientific instruments; improvisation of science gadgets; and correct techniques in collecting water sample.

: Systematism; orderliness; perseverance; cooperation; respect for authority; resourcefulness; and objectivity.

: Kuantan River; Human Resources; chemist; microbiologist; and local town council officials.

1.

2.

3 _ .

4.

5.

6.

7.

8.

9.

A class of 40 students is divided into 8 groups of 5 students per group.

Assign 4 groups to carry out procedures upstream (i.e. before factory) and 4 groups downstream (i.e. after factory).

Of the 4 groups (upstream and downstream) 2 groups monitor abiotic and 2 groups monitor biotic.

Abiotic: pH; turbidity; colour; smell; and light penetration.

Biotic: microscopic and macroscopic; and aquatic life in the river water.

Experiments at sites.

Experiments on collected water sample.

Consultations with chemist and microbiologist.

Discussion/presentation of findings.

Index

.

Abiotic Factors . . . .

Acid Rain . . . . . .

Adult Education . . . .

Aquatic Ecosystem . . .

Aqueous Matrix . . . .

Atmosphere . . . . .

Autotrophs . . . . .

Basic Needs . . . . .

Benthos . . . . . . .

Bioethics . . . . . .

Biofuel . . . . . . .

Biogeochemical Cycle . .

Biomass . . . . . . .

Biosphere . . . . . .

Biotic Factors . . . . .

Carbohydrates . . . .

Carbon Cycle . . . . .

Carbon Dioxide . . . .

Carnivores . . . . . .

Carrying Capacity . . .

CFC . . . . . . . .

Chronic Pulmonary Disease

Community . . . . .

Concept Maps . . . .

Consumers . . . . . .

Consumption Explosion .

Cost Benefit Analysis . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

.......

Curriculum . . . . . . . . . . . . . . . .

. . . . 17,18

. . . . 92,93,163

. . . . 166

. . . . 115

. . . . 19

. . . . 33

. I . . 17

. . . . 176

. . . . 23

. . . . 202

. . . . 230

. . . . 58,61

. . . . 53

. . . . 41

. . . . 17

. . . . 17

. . . . 63

. . . . 61,62

. . . . 49

. , . . 164

. . . . 85, 87,98

. . . . 10

. . . . 211,212

. . . . 185,186

. . . . 17,74

. . . . 165

. . . . 134

. . . . 12, 183,184

_____l____---... -._

Decision Makers . . . . . . . . . . . . . . . . . 6,147

Decomposers . . . . . . . . . . . . . . . . . . . 49

Deforestation . . . . . . . . . . . . . . . . . . 9596

Ecological Concepts . . . . . . . . . . . . . . . . 174,175

Ecology . . . . . . . . . . . . . . . . . . . . . 7,13,27

Ecosystem . . . . . . . . . . . . . . . . . . . . 8,30,71,115,119

Edaphic Factors . . . . . . . . . . . . . . . . . . 19

Educational Game . . . . . . . . . . . . . . . . . 221

EIA Methodologies . . . . . . . . . . . . . . . . 152

Energy . . . . . . . . . . . . . . . . . . . . . 41,42

Environmental Awareness . . . . . . . . . . . . . . 167

Environmental Education . . . . . . . . . . . . . . 163,166,171

Environmental Impact Assessment . . . . . . . . . . . 148,150

Eutrophication . . . . . . . . . . . . . . . . . . 106,108

Evapo Transportation . . . . . . . . . . . . . . . . 19

Family Planning . . . . . . . . . . . . . . . . . . 205

Fermentation . . . . . . . . . . . . . . . . . . . 46

Film . . . . . . . . . . . . . . . . . . . . . . 218

Flood . . . . . . . . . . . . . . . . . . . . . 163

Food Chain . . . . . . . . . . . . . . . . . . . 49

Food Web . _ . . . . . . . . . . . . . . . . . . 49

Global Warming . . . . . . . . . . . . . . . . . . 228,230

Green House Effect . . . . . . . . . . . . . . . . 90,163,228

Green Revolution . . . . . . . . . . . . . . . . . 3

Hazardous Wastes . . . . . . . . . . . . . . . . . 95

Herbivores . . . . . . . . . . . . . . . . . . . 49

IEEP . . . . . . . . . . . . . . . . . . . . . 166

Instrumentation . . . . . . . . . . . . . . . . . . 238

Instruments . . . . . . . . . . . . . . . . . . . 237,238

In-Service Training . . . . . . . . . . . . . . . . . 167

Itai Itai . . . . . . . . . . . . . . . . . . . . . 100

IUCN . . . . . . . . . . . . . . . . . . . . . 164

Living Organisms . . . . . . . . . . . . . . . . . 14

Mangrove Forests _ . . . . _ . . . . . . . . . . . 4

Marine Pollution . . . . . . . . . . . . . . . . . 108

.

Minemata Disease ................. 99

Minerals . . . ................. 123

Molasses . . . ................. 230

Monitoring . . . ................. 237,238

Mycorrhiza . _ . ................. 27

Natural Resources ................. 177

Nekton . . . . ................. 23

Network . . . ................. 152

Neuston ....................... 23

Nitrogen Cycle .................. 64

Nitrogen Fixation ................. 28

Noise Pollution .................. 215

Nutrient Cycle .................. 43

Nutrition .................... 44

Oxidation .................... 46

Ozone ..................... 83,163

Pedagogical Aspects ................ 4,163

Pestisides .................... 106

Phosphorous Cycle ................. 65

Photochemical Smog ................ 103

Photosynthesis .................. 17

Pollution .................... 175

Population Dynamics ................ 72

Practicum .................... 206,207

Predation .................... 27

Pre-service Training ................ 167

Primary Production ................. 46

Problem Solving .................. 17

Producer .................... 17

Productivity ................... 28

Pyramid ..................... 52,53,54,74

Radiation .................... 37

Red Tide .................... 108

Research In EE .................. 251

Resource Recovery ................. 140

..__ ---_ - . . _-__

Secondary Production ......

Simulation ..........

Simulation Modelling ......

Solar Output .........

Solar Radiation ........

Species Diversity .......

Stockholm Conference .....

Sulphur Cycle ........

Sustainable Development ....

Teacher Training .......

Teaching Material .......

Terrestrial Community .....

Thermodynamics .......

Toxic Chemicals ........

Toxic Effects .........

Trophic Level ........

Tropical Forest ........

Tropical Rain Forest ......

Ultravoilet Radiation ......

UNEP ...........

University Education ......

Values Education .......

Vocational Education ......

Water Resources .......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

......

. . 48

. . 221,222

. . 157

. . 35

. . 25,26

. . 25,26

. . 166

. . 66

. . 139,140

. . 168,251

. . 227,253

. . 22,23

. . 46

. . 102

. . 100

. . 28

. . 95,96

. . 17

. . 84

. . 92,110,166

. . 168

. . 189,191

. . 167

. . 110, 178

.” -

sourcebook in environmental education for secondary school teachers

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