1. Energy Flow in Ecosystems
How Ecosystems Work
Energy Flow in Ecosystems

2. Ecological Pyramids

3. Ecological Pyramids
Show relative amounts of energy or matter within trophic levels of food chains and food webs

4. Energy Pyramids shows amount of available energy at each level
most energy is consumed at each level for biological processes or lost as heat
only about 10% of energy is transferred to next level
0.01%
0.1% 1%
10%
100%

5. Trophic Levels
Each time energy is transferred, some of the energy is lost as heat.
Therefore, less energy is available to organisms at higher trophic levels.
One way to visualize this is with an energy pyramid.

6. 0.01%
0.1% 1%
10%
100%

7. Heat Heat Heat 100% 10% 1% Autotrophs Herbivores Carnivores Consumed

8. Biomass Pyramid
represents available food (organic matter)

9. Pyramids of Numbers
represents the number of individuals at each trophic level

10. Energy Loss Affects Ecosystems
Decreasing amounts of energy at each trophic level affects the organization of an ecosystem.
Energy loss affects the number of organisms at each level.
Energy loss limits the number of trophic levels in an ecosystem.

11. Review How does energy flow through an ecosystem?
Draw a food chain with at least 3 consumers.
What do the arrows indicate?
To show all of the feeding relationships in an ecosystems, biologist use a/(an) __ __.
How much energy is transferred from one organism to the other?
What happens to the energy that is not transferred?
What is biomass?
What information is found in a biomass pyramid?
What is represented by a pyramid of numbers?
Review

12. The End