How does energy move through an ecosystem?

• Energy moves from one organisms to another when it is eaten.

What are Trophic Levels• Each step in this transfer of energy is know as a

trophic level– The main trophic levels are producers, consumers, and

decomposers

What is the Food Chains ?• The energy flow from one trophic level to the

other• A food chain is simple and direct• It involves one organism at each trophic level– Primary Consumers – eat producers– Secondary Consumers – eat the primary

consumers– Tertiary Consumer-eat the secondary consumer– Decomposers – bacteria and fungi that break

down dead organisms and recycle the material back into the environment

What is a Food Web

• Most organisms eat more than JUST one organism

• When more organism are involved it is known as a FOOD WEB

• Food webs are more complex and involve lots of organisms

Transfer of Energy

• When a zebra eats the grass, it does not obtain all of the energy the grass has (much of it is not eaten)

• When a lion eats a zebra, it does not get all of the energy from the zebra (much of it is lost as heat)

Law of Thermodynamics2nd Law of Thermodynamics: energy is not transferred from one object/organism to the next with 100% efficiency.

Some of the energy is lost to the environment.

Energy Pyramid shows the amounts of energy that moves from one level to the next

Energy Flow

• The ecological pyramid shows the relative amounts of energy or matter.

• Producers make up the first level

• Consumers make up the second, third and higher

Energy Flow • Only about 10% of the energy

available within one trophic level is transferred to organisms at the next trophic level.

• The other 90% is used by the

organism to carry out its life processes or it is lost to the environment

• Biomass is the total amount of living tissue within a given trophic level.

Ecological Pyramid

Food Web: land and water connected

Food Web

• Notice that the direction the arrow points the arrow points in the direction of the energy transfer, NOT “what ate what”

Energy Transfer

• Only about 10% of energy is transferred from one level to the next

• The other 90% is used by the organism to carry out its life processes or it is lost to the environment

Ecological Pyramid

• An ecological pyramid shows the relationship between consumers and producers at different trophic levels in an ecosystem

• Shows the relative amounts of energy or matter contained at each trophic level

• The Pyramid shows which level has the most energy and the highest number of organisms

Ecological Pyramidonly 10% of energy is passed on through consumption

Ecological Pyramid

• Which level has the most energy?• Which level has the most organisms?• Which level has the least organisms?• Which level has the least energy?