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Population Density

Population density is total population size per unit of area.

Population densities depend on: Interactions within the environment Quality of habitat Density dependent factors Density independent factors

Carrying capacity is the maximum number of organisms that can be supported in a given habitat.

Population size can be measured by several sampling techniques.


Population Growth

Exponential vs. Logistical Growth


Survivorship in Populations


Reproductive Strategies

r- Selected (maximum growth rate, below carrying capacity)

Early reproduction Short life span High mortality rate Little or no parental

care Large investment in

producing large numbers of offspring

Below carrying capacity Examples:

Bony fish Grasshoppers

K-Selected (maximizes population size near carrying capacity)

Late reproduction Long life span Low mortality rate Extensive parental care Greater investment in

maintenance and survival of adults

At or near carrying capacity

Examples: Sharks Elephants


Limits on Population Growth

Density Dependent Limits Food Water Shelter Disease

Density Independent Limits Weather Climate

Water and shelter are critical limiting factors in the desert.

Fire is an example of aDensity independent Limiting factor.


Population Age Structure

Differences in environmental conditions and past history may cause populations to differ in their age distributions.

The future growth of a population depends on its current age distribution.


Human Population Growth

Human population growth does not currently show density effects that typically characterize natural populations.

In natural populations, per capita population growth rate decreases with population size, whereas global human population growth rate has a positive relationship.

Human population growth rate has been growing more than exponentially.

Limited resources eventually will cause human population growth to slow, but global human carrying capacity is not known.


r-selected Reproductive Strategy

r-selected Species: have high

reproductive rates tend to occur in

unpredictable environments

typically have type III survivorship curves


K-selected Reproductive Strategy

K-selected Species: occur near carrying

capacity experience effects

of population density

have low reproductive rates, high parental care

have type I survivorship curves.

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What are Wastes?

Basel Convention Definition of Wastes

“substances or objects which are disposed of or are intended to be disposed of or are required to be disposed of by the provisions of the law”

Disposal means

“any operation which may lead to resource recovery, recycling, reclamation, direct re-use or alternative uses (Annex IVB of the Basel convention)”


Kinds of Wastes

Solid wastes: domestic, commercial and industrial wastes especially common as co-disposal of wastes

Examples: plastics, styrofoam containers, bottles, cans, papers, scrap iron, and other trash

Liquid Wastes: wastes in liquid form

Examples: domestic washings, chemicals, oils, waste water from ponds, manufacturing industries and other

sources


Classification of Wastes according to their Properties

Bio-degradable

can be degraded (paper, wood, fruits and others)

Non-biodegradable

cannot be degraded (plastics, bottles, old machines,

cans, styrofoam containers and others)

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Classification of Wastes according totheir Effects on Human Health and the

Environment

Hazardous wastes

Substances unsafe to use commercially, industrially, agriculturally, or economically that are shipped, transported to or brought from the country of origin for dumping or disposal in, or in transit through, any part of the territory of the Philippines

Non-hazardous

Substances safe to use commercially, industrially, agriculturally, or economically that are shipped, transported to or brought from the country of origin for dumping or disposal in, or in transit through, any part of the territory of the Philippines


Sources of Wastes

Households

Commerce and Industry


Sources of WastesAgriculture

Fisheries


WHAT SHOULD BE DONE Reduce Waste

- Reduce office paper waste by implementing a formal policy to duplex all draft reports and by making training manuals and personnel information available electronically.

- Improve product design to use less materials.

- Redesign packaging to eliminate excess material while maintaining strength.

- Work with customers to design and implement a packaging return program.

- Switch to reusable transport containers.

- Purchase products in bulk.


WHAT SHOULD BE DONE

Reuse

- Reuse corrugated moving boxes internally.

- Reuse office furniture and supplies, such as interoffice envelopes, file folders, and paper.

- Use durable towels, tablecloths, napkins, dishes, cups, and glasses.

- Use incoming packaging materials for outgoing shipments.

- Encourage employees to reuse office materials rather than purchase new ones.


2. Key terms for the water cycle:2. Key terms for the water cycle:a. Precipitation: moisture that falls to

the ground (rain, snow, sleet, hail)

b. Evaporation: changing from liquid to gas (water to water vapor)

c. Transpiration: plants give off water vapor from their leaves to the air

d. Condensation: changing from gas to a liquid


II. Oxygen Cycle:

1. Plants make food by photosynthesis They use carbon dioxide (CO2) to make oxygen (O2)

2. Animals breathe out carbon by respiration

They use oxygen (O2) and breathe out carbon dioxide (CO2)

By the way … humans are animals too


Carbon Cycle: notice photosynthesis and respiration are back … they both involve CO2 (now we’re looking at the C for carbon)

fossil fuelsfossil fuels

photosynthesisphotosynthesis

carbon dioxidecarbon dioxidedissolved in waterdissolved in water

decompositiondecompositionof organismsof organisms

respirationrespiration

carboncarbondioxidedioxide

in airin air

photosynthesisphotosynthesis

combustioncombustionrespirationrespiration


nitrogen inatmosphere

animals

denitrifyingbacteria

nitrifyingbacteria

nitrifyingbacteria

ammonium

ammonification

decomposers

plant

nitrogen-fixingbacteria in soil

nitrogen-fixingbacteria in

roots

nitrates

nitrites

IV. The Nitrogen Cycle1. The nitrogen cycle mostly takes place underground.

2. Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation.

– Some nitrogen-Some nitrogen-fixing bacteria fixing bacteria live inlive innodules on thenodules on theroots of plants;roots of plants;others liveothers livefreely infreely inthe soil.the soil.


3. Ammonia released into the soil is transformed into ammonium.

4. Nitrifying bacteria change the ammonium into nitrate.

nitrogen inatmosphere

animals

denitrifyingbacteria

nitrifyingbacteria

nitrifyingbacteria

ammonium

ammonification

decomposers

plant

nitrogen-fixingbacteria in soil

nitrogen-fixingbacteria in

roots

nitrates

nitrites

– Nitrogen moves Nitrogen moves through the through the foodfoodweb and web and returnsreturnsto the soil to the soil duringduringdecomposition.decomposition.


geologic upliftingrain

weathering ofphosphate from rocks

runoff

sedimentationforms new rocks

leaching

phosphate in solutionanimals

plants

decomposers

phosphatein soil

V. Phosphate CycleV. Phosphate Cycle

1.1. PhosphatePhosphate is released by the is released by the weathering of rocks.weathering of rocks.

a. Phosphorus leachesPhosphorus leaches into groundwater into groundwater from the soil and from the soil and is locked in is locked in sediments. sediments.

b.b. Both mining andBoth mining and agriculture add agriculture add phosphorus into phosphorus into the environment. the environment.

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Kyoto Protocol Framework

stabilize greenhouse gas emissions to prevent anthropogenic interference with the climate system

emission targets for industrialized countries between 2008-2012 are collectively about 5% lower than 1990 emissions

US target is 7% reduction developing countries do not have quantified targets

six gases CO2, CH4, N2O, HFCs, PFCs, SF6


The Protocol is subject to ratification, acceptance, approval or accession by Parties to the Convention.

It shall enter into force on the ninetieth day after the date on which not less than 55 Parties to the Convention, incorporating Annex I Parties which accounted in total for at least 55 % of the total carbon dioxide emissions for 1990 from that group, have deposited their instruments of ratification, acceptance, approval or accession.

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