week 2 ecological processes

7/29/2019 Week 2 Ecological Processes

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Week 2

SYCPA Regents Prep

LivingEnvironment

Ecological Processes


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Week 2 Ecological Processes

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This packet provides a review of concepts that may be tested in the NYS Living

Environment Regents and is based on the NYS Core Curriculum. This course will cover individual

topics over 6 weeks as listed below:

Week 1 - Scientific Method

Week 2 - EcologyWeek 3 - Human Body SystemsWeek 4 Molecular Biology & Genetics

Week 5 - LabsWeek 6 - Evolution & Human Impact

The order of these topics is chosen based on their average weight in past Living

Environment Regents.

The individual packets will consist of a review for the specific topic followed by past

regents questions.

Good Luck!

SYCPA Say Yes Collegiate Prep Academy


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Ecological Processes Review

Biospheres

Vocabulary: abiotic factors, biotic factors, carrying capacity, competition, predator, prey, parasite,

host, scavenger, decomposer, autotroph, producer, herbivore, primary consumer, carnivore,secondary consumer, omnivore, heterotroph, food chain, food web, energy pyramid, transpiration

Biotic vs. AbioticOrganisms with similar needs may compete with one another for resources, including food,space, water, air, and shelter. In any particular environment, the growth and survival oforganisms depend on the physical conditions including light intensity, temperature range,mineral availability, soil type, and pH. Physical or non-living factors such as these whichinfluence living things are called abiotic factors. Living factors which influence living thingsare called biotic factors. Some examples of biotic factors include disease and predation.

Energy FlowEnergy flows through ecosystems in one direction, typically from the Sun, throughphotosynthetic organisms or producers, to herbivores to carnivores and decomposers. Thechemical elements that make up the molecules of living things pass through food webs andare combined and recombined in different ways. At each link in a food web, some energy isstored in newly made structures but much energy is lost into the environment as heat.Continual input of energy from sunlight is required to keep this process going. Energypyramids are often used to show the flow of energy in ecosystems.

Material CyclesThe atoms and molecules on the Earth cycle among the living and nonliving components ofthe biosphere. Carbon dioxide and water molecules used in photosynthesis to form energy-rich organic compounds are returned to the environment when the energy in thesecompounds is eventually released by cells through the processes of cell respiration andother life activities. The number of organisms any environment can support is calledits carrying capacity. The carrying capacity of an environment is limited by the availableenergy, water, oxygen, and minerals, and by the ability of ecosystems to recycle the remainsof dead organisms through the activities of bacteria and fungi.Living organisms have thecapacity to produce populations of unlimited size, but available resources in theirenvironments are finite. This restricts the growth of populations and

produces competition between organisms.

Organism RelationshipsOrganisms interactions may be competitive or beneficial. Organisms may interact with oneanother in several ways. Some of these relationshipsinclude producer/consumer, predator/prey, orparasite/host relationships. Other organismsinteractions include those in which one organism may cause disease in, scavenge,ordecomposeanother.


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Feeding RelationshipsEnergy flows through ecosystems in one direction, typically from the Sun, throughphotosynthetic organisms including green plants and algae, to herbivores to carnivores and

decomposers. Green plants and algae are called autotrophs orproducer organisms, as theycapture solar energy to make sugars in the process ofphotosynthesis. Herbivores orprimary consumers use the producer organisms to providethem with their food. Carnivores are secondary consumers as they eat the primaryconsumers as their source of food. Some organisms are capable of functioning as primaryconsumers (eating plant material) and as secondary consumers (eating animal material).These organisms are called omnivores. Humans are examples of omnivores. All consumersare examples of heterotrophic organisms, as they can not make their own food using thesun, but depend upon the ingestion of other organisms for their nutrition.

Food ChainsIf an ecosystem is to be self-sustaining it must contain a flow of energy. One wayof representing the flow of energy through the living components of anecosystem is through the use of a food chain. A food chain indicates the transferof energy from producers through a series of organisms which feed upon eachother.

A Food Chain

Note that the arrows in the food chainpoint to the organisms which are doing

the eating. Thus the arrows in the food

chain represent the flow of energythrough the ecosystem.

The algae and floating

plants aretheproducers in this

food chain. The aquaticcrustaceans are

the primary

consumers which eatthe producers.

Fish are secondary

consumers eating the

primary consumers.

A food chain may also

contain third level or

other consumers asindicated by the

raccoons in this food

chain.


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Food Webs

In a natural community, the flow of energy and materials is much morecomplicated than illustrated by any one food chain. A food web is a series ofinterrelated food chains which provides a more accurate picture of the feeding

relationships in an ecosystem, as more than one thing will usually eat a particularspecies.

A Food Web

Energy flow in a

food web alsostarts with the

producer

organisms

through the

various levels ofconsumer

organisms as in afood chain.

Energy Pyramids

An energy pyramid provides a means of describing the feeding and energyrelationships within a food chain or web. Each step of an energy pyramid showsthat some energy is stored in newly made structures of the organism which eatsthe preceding one. The pyramid also shows that much of the energy is lost when

one organism in a food chain eats another. Most of this energy which is lost goesinto the environment as heat energy. While a continuous input of energy fromsunlight keeps the process going, the height of energy pyramids (and therefore the lengthof food chains) is limited by this loss of energy.

An Energy Pyramid


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The picture at the left is an energy pyramid. Producer organismsrepresent the greatest amount of living tissue orbiomass at the

bottom of the pyramid. The organisms which occupy the rest of

the pyramid belong to the feeding levels indicated in each step.

On average, each feeding level only contains 10% of the energyas the one below it, with the energy that is lost mostly being

transformed to heat.

Material Cycles:

Water Cycle

The atoms and molecules on the Earth cycle among the living and nonliving components ofthe biosphere. Some of the water molecules which are used in photosynthesis are returnedto the environment. The change of water from the liquid to the gas state is calledevaporation, while the water lost to the atmosphere by the activities of plants is referred toas transpiration water loss. This water vapor eventually condenses to form clouds, and is

returned to the earth as precipitation. This process is called the water cycle. The processesof cell respiration and excretion also releases some water to the environment as well.

The Water Cycle


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Carbon-Oxygen Cycle

Carbon dioxide molecules are used in the process of photosynthesis to form energy-richorganic sugar compounds. These carbon dioxide molecules are returned to the environmentby the process of cell respiration, when the energy from these compounds is eventuallyreleased by cells. Some carbon is also returned to the environment by the decomposition ofdead organisms.

Oxygen is required by many living things to release the energy in their food in the process ofaerobic cellular respiration. Oxygen is released to the environment as a waste product of theprocess of photosynthesis.

The Carbon-Oxygen Cycle


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Other compounds, such as nitrogen, are cycled in the environment when organismssynthesize proteins from simpler compounds and then return these nitrogen compounds tothe environment when they die and decompose.

Role of Decomposers

The number of organisms any environment can support is the carrying capacity of theenvironment. Carrying capacity is limited by the available energy, water, oxygen, andminerals, and by the ability of ecosystems to recycle the remains of dead organisms throughthe activities of decomposers such as bacteria and fungi.

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Ecosystems/Communities

Vocabulary: limiting factors, ecological succession, symbiotic, parasitism,mutualism, commensalism, pioneer species, climax community

Abiotic FactorsAbiotic factors are those non-living physical and chemical factors which affect theability of organisms to survive and reproduce.

Some Abiotic Factors

light intensity temperature range type of soil or rock pH level

(acidity or alkalinity)

water availability dissolved gases level of pollutant

Abiotic factors vary in the environment and determining the types and numbers of organisms that exist in thatenvironment. Factors which determine the types and numbers of organisms of a species in an ecosystem arecalled limiting factors. Many limiting factors restrict the growth of populations in nature. An example of thiswould include low annual average temperature average common to the Arctic restricts the growth of trees, asthe subsoil is permanently frozen.

Biotic Factors

Biotic factors are all the living things or their materials that directly or indirectly affect an organism in its


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environment. This would include organisms, their presence, parts, interaction, and wastes. Factors such asparasitism, disease, and predation (one animal eating another) would also be classified as biotic factors.

Some Biotic Factors

parasitism disease predation

Ecological Succession

The environment may be changed greatly through the activities of organisms, includinghumans, or when climate changes. Although sometimes these changes occur quickly, inmost cases species gradually replace others, resulting in long term changes in ecosystems.These changes in an ecosystem over time are called ecological succession. Ecosystems mayreach a point of stability that can last for hundreds or thousands of years. If a disaster

occurs, the damaged ecosystem is likely to recover in stages that eventually result in a stablesystem similar to the original one.

Feeding RelationshipsOrganisms may interact with one another in several ways. One example of an organisminteraction is that of a producer/consumer relationship. A producer is any organism capableof making its own food, usually sugars by photosynthesis. Plants and algae are examples ofproducers. Aconsumer is any organism which eats another organism. Several different typesof consumer organisms exist. A herbivore is a consumer which eats primarily plant material.

A deer is an example of a herbivore. A carnivore consumes primarily animal material. Anomnivore eats both plant and animal matter. Humans are examples of omnivorousorganisms.

A predator is a type of carnivore that kills its food. The organism the predator feeds upon iscalled its prey. A wolf and rabbit would provide an example of a predator/preyrelationship. Scavengers feed upon organisms that other organisms have killed. A crowfeeding off dead carrion in the highway would be an example of scavenger in this instance.


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Scavengers Feeding

The cartoon above represents a typical situation wherevultures are acting as scavengers feeding on a dead

rhinoceros.

Symbiotic Relationships

Close living associations are called symbiotic relationships. Parasitism is an example of such arelationship. In this situation, the parasite feeds upon the tissues or fluids or anotherorganism, but usually does not kill the organism it feeds upon, as this would destroy its foodsupply. The organism the parasite feeds upon is called the host organism. An example of thissort of relationship would be fleas on a dog or athlete's foot fungus on a human.

Types of Symbiosis

parasitism: the parasite benefits at the expense of the host mutualism: both organisms benefit from the association commensalism: one organism is benefited and the other is

unharmed

Other Relationships

Some organisms such as certain pathogenic bacteria may cause disease in other

organisms.Decomposer organisms use the energy of dead organisms for food and break themdown into materials which can be recycled for use by other organisms. Bacteria of decay andmany fungi are examples of decomposer organisms.

Ecosystem StabilityThe interrelationships and interdependencies of organisms affect the development of stable


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ecosystems. The types of animal communities found in an ecosystem is dependent upon thekinds of plants and other producer organisms in that ecosystem.

SuccessionThe environment may be altered in substantial ways through the activities of humans, other

living things, or when natural disasters occur, such as climate changes and volcaniceruptions. Although these changes are sometimes occur very quickly, in most cases speciesreplace others gradually, resulting in long-term changes in ecosystems. These gradual longterm changes in altered ecosystems are called ecological successions. Ecosystems tend tochange with time until a stable system is formed. The type of succession which occurs in anecosystem depends upon climatic and other limitations of a given geographical area.

A Typical New York State Succession

Pioneer organisms are the first organisms to reoccupy an area which has been disturbed bya disruption. Typical pioneers in a succession include grasses in a plowed field or lichens onrocks. These pioneer organisms modify their environment, ultimately creating conditions

which are less favorable for themselves, but establishing conditions under which moreadvanced organisms can live. Over time, the succession occurs in a series of plant stageswhich leads to a stable final community which is very similar to the plant community whichoriginally existed in the ecosystem. This final stable plant community is called a climaxcommunity. This community may reach a point of stability that can last for hundreds orthousands of years.

A Pond Succession Sequence


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It has been observed that when natural disasters occur, such as a floods or fires, thedamaged ecosystem is likely to recover in a series of successional stages that eventuallyresult in a stable system similar to the original one that occupied the area.

A Typical New York State Succession

This chart represents a typical succession which is observed in

New York State. The annual grasses represent thepioneer or first

organisms in this succession. The beech-maple forest wouldrepresent a typical Northern New Yorkclimax community. The

climax community will last hundreds or thousands of years unless

again disrupted. A forest containing oak and/or hickory treeswould be a more typical Southern New York climax community.

Populations


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Vocabulary: ecology, population, community, ecosystem, biosphere, cycling,biodiversity, habitat, niche

Carrying Capacity

Carrying capacity is the maximum number of organisms the resources of anecosystem can support. The carrying capacity of the environment is limited by theavailable abiotic and biotic resources (limiting factors), as well as the ability ofecosystems to recycle the residue of dead organisms through the activities ofbacteria and fungi.

Ecological OrganizationEcology is the study of the interactions of living things with each other and their physicalenvironment. The living things on earth may be organized into four different levels ofecological organization. These levels of organization are indicated in the table below.

Levels of Ecological Organization

1. populationall the members of one species in an

area

2. communityall the members of the different

interacting species in an area

3. ecosystem

all the members of a community plus

the abiotic (physical) factors

influencing them

4. biosphere entire region of the earth whereliving things may be found

A Representation of A Community


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This is a community of many different organisms which could

exist on milkweed. The community contains many organisms of

different species in one location.

A Pond Ecosystem

This is a pond ecosystem. There are many organisms of differentspecies in this location interacting with the air, water, and land

components of this environment.


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Nutritional InteractionsAll ecosystems must have three basic kinds of nutritional interactions in order to be stableand self-sustaining. These nutritional interactions involve producers, consumers, anddecomposers.

A producer organism is one that is capable of trapping the Sun's energy to make glucosesugar in the process of photosynthesis. Plants and algae are examples of producerorganisms. Sometimes producer organisms are called autotrophs. Consumer organismsdepend upon and eat other organisms for their food. Sometimes consumer organisms arecalled heterotrophs. Many different categories of consumer organisms exist.A herbivore eats primarily plant material, while acarnivore eats primarily other animals.An omnivore is a consumer that eats both plant and animal material. Humans are anexample of an omnivore. A decomposer is a special category of consumerorganism.Decomposers break down dead organic matter and change it to simpler nutrientswhich can be recycled in the ecosystem.

Circle of LifeIn order for an ecosystem to sustain life, several conditions must be met.

Some Conditions for a Stable Ecosystem

A constant source of energy and a living system capable ofincorporating this energy into organic molecules. (Thismeans plants and/or algae are needed to convert solar

energy to the energy of sugars by the process of

photosynthesis.)

A cycling of materials between organisms and theirenvironment. (Some material cycles include oxygen,

carbon dioxide, water, and nitrogen.) Decomposers, such

as bacteria of decay and some fungi are needed in everyecosystem to return and recycle necessary materials to the

environment.

The greater the number of different populations that interact within an

ecosystem, the more stable and self-sustaining the ecosystem becomes. Thenumber of different populations within an ecosystem is sometimes referred toas biodiversity. These interactions contribute to the overall maintenance of theecosystem.


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Niche ConceptCompetition occurs when two different species or organism living in the sameenvironment orhabitat use the same limited resources such as food, water,space, light, oxygen, or minerals. A resource which restricts the growth of a

population is sometimes called a limiting factor. The more similar therequirements of the organisms involved, the more intense their competition willbecome. If two different species compete for the same food source, reproductivesite, water, or other limiting factor, one species may be eliminated. Thisestablishes one species per niche in an ecosystem. A nicherefers to an organismsrole, especially its feeding role, in a community. This allows different species tocoexist and helps to contribute to the overall stability of the ecosystem.

Niche Concept

Three different species of a kind of bird called a warbler are

coexisting in this tree, even though the eat the same kind of food.

These birds are feeding in different levels of this tree. In this way,these birds have evolved to occupy differentniches.


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Human Biosphere/Influence

Vocabulary: biodiversity, monoculture, greenhouse effect, endangered species,exotic/invasive species, acid precipitation, global warming, CFCs, SEQR,

biodegradable

BiodiversityDue to evolution, there is a great number of different organisms which fill many differentroles in ecosystems. The number of different organisms in an ecosystem is calledbiodiversity. Increased biodiversity increases the stability of the ecosystem. Biodiversity alsoensures the availability of diverse genetic material that may lead to future discoveries withsignificant value to humans. As diversity is lost, potential sources of these materials forthese discoveries may be lost with it. A great diversity of species provides for variationswhich increase the chance that at least some living things will survive in the face of largechanges in the environment.

BiodiversityAs a result of evolutionary processes, there is a diversity of organisms and a diversity of rolesin ecosystems. Biodiversity refers to the differences in living things in anecosystem. Increased biodiversity increases the stability of the ecosystem as it provides formore genetic variation among species. A great diversity of species increases the chance thatat least some living things will survive in the face of large changes in the environment.

The Need for Biodiversity


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Human Influences on BiodiversityWhen humans alter ecosystems either by removing specific organisms, seriousconsequences may result. Human beings are part of the Earths ecosystems. Human

activities can, deliberately or accidentally, change the equilibrium in ecosystems. Humans aredestroying other species as a result of population growth, consumption, and technology.

Human destruction of habitats through direct harvesting, pollution, atmospheric changes,and other factors is especially threatening current global biodiversity.

An example of a human activity which has decreased biodiversity is the useof monoculture in modern agricultural practices. Monocultureinvolves planting one varietyof a species over a huge area. This leaves this area more vulnerable to predation or diseaseand the loss of many or all species.

Uses of BiodiversityIn addition to the aesthetic beauty added to the world by many different

organisms, biodiversity also ensures the availability of a rich variety of genetic material thatmay lead to future agricultural or medical discoveries with significant value to humankind. Asdiversity is lost, potential sources of these materials may be lost with it.

Interrelationships

The Earth has limited resources to support the organisms that live on it. Increasing humanpopulation numbers are putting great pressure on many of these limited resources anddeplete those resources which can not be renewed. Many different natural processes occurwithin those ecosystems influencing humans. Some of these processes include atmosphericquality. soil generation and conservation, energy flow, the water cycle, waste removal andrecycling. Human activities are altering the equilibrium involved in these natural processesand cycles. If these changes due to human activities are not addressed, the stability of theworld's ecosystems may irreversibly affected.

Technological Developments

Human activities which have harmed ecosystems have resulted in a loss of diversity in bothliving things and the nonliving environment. Examples of these changes include land use, thecutting of vast areas of forest, and pollution of the soil, air, and water. Another way humanshave changed ecosystems in a harmful way is by adding or removing specific organisms to

these ecosystems Our ever increasing demand for energy has impacted ecosystemsnegatively as well. Many environmental risks are associated with our use of fossil andnuclear fuels.

Many factors associated with human populations have influenced environmental quality.These include population growth and distribution on our planet, our use of resources, the


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ability of technology to solve environmental problems, as well as the role of economic,political, ethical, and cultural views in solving these problems.

ImprovementsIndividual choices and the actions of society can contribute to the improvement of our

environmental problems. Our choices which must include an assessment of the risks, costs,benefits, and trade-offs of new technologies and continued human expansion. All changesand proposed improvements need to consider both the human and environmental impact ofthe change.

Interrelationships

The Earth has limited to resources to support populations of humans and other organisms.Our ever increasing human numbers is depleting many of our planet's resources and placingsevere stress on the natural processes that renew many of our resources.

Ecosystem Processes

Natural ecosystems are involved in a wide variety of natural processes influencing humansand other organisms. The activities of humans in the environment are changing many ofthese natural processes in a harmful fashion. Some of these natural processes and a briefdescription of a human influence on these processes is indicated in the table which follows.

Human Influence on Some Ecosystem Processes

Ecosystem Process Human Influence

Generation of SoilsAgricultural practices have exposedsoil to the weather resulting in great

loss of topsoil.

Control of the Water

Cycle

The cutting of forests and other

human activities have allowedincreased uncontrolled runoff

leading to increased erosion and

flooding.

Removal of Wastes

Untreated sewage wastes and runofffrom farms and feedlots have led to

increased water pollution.

Energy Flow

Some industries and nuclear plantshave added thermal pollution to the

environment. The release of some

gases from the burning of fossil fuels

may be slowly increasing the Earth'stemperature.


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(Greenhouse Effect).

Nutrient Recycling

The use of packaging material which

does not break down, burning ofrefuse, and the placing of materials

in landfills prevents the return ofsome useful materials to theenvironment.

Some Detrimental Human ActivitiesHumans are part of the Earth's ecosystem. Human activities can eitherdeliberately or inadvertently alter the balance of an ecosystem. This destructionof habitat, whether accidental or intentional, is threatening the stability of theplanet's ecosystems. If these human influences are not addressed, the stability of

many ecosystems may be irreversibly affected. Some of the ways that humansdamage and destroy ecosystems are indicated in the table below.

Some Ways Humans Adversely Influence Ecosystems

Human Influence Effect on Ecosystems

Population growthOur increasing numbers are using excessiveamounts of the Earth's limited resources.

Overconsumption

Industrialized societies are using more

resources per person from our planet than

people from poor nations.

Advancing

Technologies

Often we introduce technology without

knowing how it will influence the

environment

Direct Harvesting

This has resulted in a large loss ofrainforest and the many products associated

with its biodiversity.

Pollution

Land, air, water, and nuclear pollution have

had many adverse influences on

ecosystems.

Atmospheric

Changes

These include the addition of Greenhouse

gases mostly due to the burning of fossilfuels and depletion of our stratospheric

ozone layer.

Other pollutants also have negative effects

on living things.


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Technological Developments

Human technologies which degrade the environment result in a loss of diversity in the livingand nonliving environment. Biodiversity refers to the differences in living things in anecosystem. Many of our technologies and resource use practices have resulted in anirreversible loss of biodiversity.

Some examples of human activities which have negatively influenced other organismsinclude our land use practices and pollution. Excessive land use decreases the space andresources available to other species on the planet. Air, soil, and water pollution changes thecomposition of these environmental resources, making them harmful and unusable forother species and sometimes ourselves.

Endangered Species

Endangered species are those species which are threatened with destruction due to habitat

destruction or other factors. Animals which were once endangered but are presentlysuccessfully reproducing and increasing their numbers are the bison, gray wolvesand egrets. Other endangered animals which are currently responding toconservation efforts and beginning to make a comeback are the whooping crane,bald eagle, and peregrine falcon. Even with these successes, the future of manyendangered species remains in doubt.

Exotic SpeciesThe importation of some organisms have caused problems for native organisms.Organisms which are imported into an area from another region are called exoticspecies. Many examples of this are found world-wide. Some common examplesof exotic species having negative effects would include the rabbits and deerwhich were imported into Australia. These exotic species won the competitionwith many native herbivorous marsupials and became nuisance species. Thestarling was brought into the United States from Europe. The starling has outcompeted many of our native songbirds. We also have alien invasive species

which have caused problems in New York State. These include the plants such asthe Water Chestnut, Eurasian Water milfoil, and Purple Loosestrife and animalssuch as the Alewife and Zebra Mussel.

The Purple Loosestrife


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Purple loosestrife is a plant native toEurope. It was brought to North America

in the early 1800's by immigrants whovalued its beautiful purple flowers. It is

now a serious pest of wetlands. Once

purple loosestrife enters a wetland, it takesover. Common native wetland plants, such

as cattails, cannot compete with purple

loosestrife. Once these native plants arechoked out, the wildlife that depends on

them for food and shelter are also

eliminated.

Use of Fossil Fuels

Fossil fuels are becoming rapidly depleted. The use of these fuels are adding to

out air pollution problems. The search and demand for additional fossil fuelresources also impact ecosystems in a negative way. Industrialization has broughtan increased demand for and use of energy.

One of the ways the increased burning of fossil fuels has had a harmful influenceof the environment is by causing an increased incidence of acid precipitation.

How does Acid Precipitation occur?

Most acid rain influencing New York State is caused by sulfur dioxideand nitrogen dioxide pollution from the burning of fossil fuels in the

Western and Midwestern United States. These gases combine with


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water vapor in the atmosphere and fall back to the earth over New Yorkand the Eastern United States as acid precipitation.

Some Problems Associated With Acid Precipitation

Destruction of limestone and marble monuments due toincreased chemical weathering

Acidification of aquatic ecosystems destroying the life inthem

Damage forests and other plants in a variety of ways

Our increased burning of fossil fuels and the release of excess carbon dioxide to

the atmosphere associated with their combustion is also contributing tothe Greenhouse Effect orglobal warming. It is believed the increase in level ofcarbon dioxide and some other gases is not allowing much infrared or heatradiation to escape the planet into outer space. This is causing our planet toslowly warm The graphs in the table below show the link between increasingearth carbon dioxide levels and the increase in global average temperatures.

Relationship Between

Global Temperature and Carbon Dioxide Levels


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Some Consequences of Global Warming

Rising sea levels and coastal flooding Changed precipitation patterns which may result in

droughts in some regions and increased levels of crop

failure

An increase in insect borne diseases in temperate regionssuch as New York State as milder winters fail to kill the

disease carrying insects. (The increase in the incidence of

West Nile virus may be an example of this.)

Ozone DepletionCFC's (chloroflurocarbons) are very active chemicals associated with certainhuman manufacturing processes and products. This CFC pollution fromrefrigerants and plastics are destroying our thin ozone shield high up in ouratmosphere or in the stratosphere. This layer of ozone normally shields us fromexcessive incoming ultraviolet radiation. Some consequences of this everincreasing ozone depletion appear to be an increased incidence of skin cancersand cataracts in the human population.

Nuclear Energy

While nuclear energy avoids many of the pollution drawbacks associated with theincreased burning of fossil fuels, there are many risks associated with the use ofnuclear fuels for energy. Environmental dangers exist in reference to obtaining,using, and storing the wastes from these fuels. Many of the waste products ofused nuclear fuel stay in the environment for thousands of years and releaseradiation which is harmful to humans or other living things. Additionally, the waterused to cool many nuclear reactors must be released eventually to the


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environment. The thermal pollution associated with this released heat into thewater is potentially dangerous to the aquatic life in the area where this hot wateris released.

Other Factors Influencing Environmental QualityMany different factors besides industry and resource use have influences onenvironmental quality. Some factors include population growth and distribution,resource use, the capacity of technology to solve environmental problems, as wellas economic, cultural, political, and ethical views.

Some Examples of Political or Cultural Views Influencing

Environmental Quality

Wealthy people in the developed world tend to have fewerchildren.

Some countries like China have laws concerning thenumber of children a couple may have without penalty.

In some countries such as many in Latin America, familiestend to be larger as birth control violates religious and

societal norms.

In some poor cultures in third world countries, havingmany children is seen as a means of having economic

security in old age.

Through a greater awareness of ecological principles and application of theseprinciples to our natural environment, humans can help assure there will besuitable environments for succeeding generations of life on our planet.

Individuals in our societies will always have to make decisions on proposalsinvolving the introduction of new technologies. Individuals in these societies need

to make decisions which will assess the risks, benefits, trade-offs, and costs ofthese new technologies. The economic rewards of these technologies must beproperly balanced with any adverse consequences these new technologies mayhave on the environment. It may be impossible to completely assess theconsequences of introducing a new technology, but critical questions in referenceto its introduction must be asked.


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While the overall impact of humans on the planet's ecosystems have beennegative, humans have done many things to improve the overall quality for livingthings in ecosystems we have damaged or destroyed. Activities having possibleadverse effects on the environment in New York State are subject to review

by SEQR (State Environmental Quality Review Act). Some other ways in whichhumans have attempted to minimize negative impacts or improve the ecosystemswe are all a part of are listed in the table which follows.

Some Positive Influences of Humans on the Ecosystem

Sustaining endangered species by using habitat protectionmethods such as wildlife refuges and national parks.

Passing wildlife management laws, such as game laws andcatch restrictions.

Adding lime to Adirondack lakes in an effort to neutralizetheiracid pollution so the original living things in these lakescan be reintroduced.

Design new products which meet basic needs withoutgenerating pollution.

Inspection of all materials before entering the country toprevent pest introduction.

Increased use ofbiodegradable packaging materialswhich will recycle themselves quickly to the environment.

Use fuels which contain less pollutants, such as low sulfurcoal and oil.

Remove pollutants by using such devices as afterburnersor catalytic converters before they enter the air.

Review provided by regentsprep.org and The NYS Core Curriculum


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Ecological Processes Regents Questions

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week 2 ecological processes

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