Using Natural ResourcesOrganisms and Their EnvironmentEnergy and ResourcesPollution and Recycling

Objectives Explain the structure of an ecosystem Describe the effects one species can

have on an ecosystem Discuss two ways natural forces can

change ecosystems Discuss two ways humans can change

ecosystems

Key Terms Ecosystem Community Succession Hydroelectric power

Organisms and Their Environment What is an Ecosystem?

A mix of living and nonliving pieces of the environment

All ecosystems are not the same size The Earth is a very complex ecosystem A rain puddle is smaller and less complex

Living things are adapted to their ecosystem

Ecosystems are divided into communities, populations, and organisms

Organization:from large to small

Organisms and Their Environment Changes in Ecosystems

Factors can change an ecosystem Balanced ecosystems remain stable A change in one factor can affect the

whole ecosystem Sunlight, air, soil, water, animals, plants,

etc. Ecosystems will gradually return to their

original conditions Succession: repopulation over time

Succession

Organisms and Their Environment Evaluating changes in ecosystems

Short term changes, (the seasons) Long term changes, (volcanic eruptions) Climatic changes affect ecosystems, (ice

age) Changes can be caused by human activity

Building dams interrupt water supplies Changes can be caused by introduction of

nonnative species Birds, insects, amphibians are examples

Objectives Identify different sources of energy used by

living things and trace each source back to the sun

Describe the advantages and disadvantages of particular energy sources

Describe the types of conversion processes needed to produce electricity

Identify the efficiency of energy conversions

Key Terms Fossil fuels Nonrenewable resources Renewable resources Geothermal energy

Energy and Resources The search for resources

The sun is a source of energy Plants change energy from the sun into

chemical energy – converting solar to chemical

Fossil fuels form deep underground from once living matter, (dinosaurs, plants)

Fossil fuels can be solids, liquids, or gases The supply of fossil fuels is limited

Nonrenewable resources

Some see the supply of fossil fuels as a joke!

Energy and Resources Alternative sources of energy – renewable

Solar cells and solar power plants make electricity directly from sunlight

The energy of wind can be used by windmills The energy of water may be sued by

turbines in dams Geothermal energy may be collected from

“hot spots” in the Earth’s crust Nuclear energy is produced from atomic

fission

Renewable Energy Sources

Energy and Resources The efficiency of energy conversion

Energy is wasted when input is greater than output Wasted energy is generally found as heat

Wasted energy may be collected for further use Heat may be used to warm homes during

cold spells

Objectives Compare the economic and

environmental impacts of different energy sources

Identify pollutants created by use of fossil fuels

Describe types of pollution in air, water, and on land

Identify ways to reduce, recycle, and reuse.

Key Terms Pollution Global warming Eutrophication Recycling

Pollution and Recycling What causes pollution?

Natural causes – dust and ash Manmade pollution is more common –

(combustion) Air pollution

Combustion of fossil fuels carbon dioxide – one of the main pollutantsother pollutants are sulfur dioxide and nitrogen dioxide

Pollution and Recycling Water pollution

Pesticides and fertilizers May be found in quantities that make the water

“unfit” May cause eutrophication and kill water organisms

Pollution on the Land Contaminants in the soil are hard to remove

Some poisons stay in soil for long periods of time Landfill space is running out

Trash is the greatest pollutant on land

Pollution and Recycling Reducing pollution

Choosing alternatives often involves trade-offs Reusable grocery bags rather than paper or

plastic Reducing the use of energy and products

can cut down on pollution Turning off light switches when not in a room

Recycling is another way to prevent pollution Reusing materials to create new products