1. Energy Flow Within an Ecosystem
Ecology
Energy Flow Within an Ecosystem

2. Objectives
Evaluate the efficiency of energy transfer among organisms in an ecosystem.

3. The following standard will be addressed:
Standards Addressed
The following standard will be addressed:
B-3.6

4. KEY CONCEPT Pyramids model the distribution of energy and matter in an ecosystem.

5. Feeding Relationships
An Ecological Pyramid shows how energy flows through and ecosystem.
Initial source of energy is from the sun.
Base is autotrophs.
Energy decreases at each level
The total amount of energy transferred from one level to the next is only about 10%

7. Matter and Energy Flow in Ecosystems
There are three types of Ecological Pyramids:
1)Pyramid of Energy
2)Pyramid of Numbers
3)Pyramid of Biomass

8. An energy pyramid shows the distribution of energy among trophic levels.
energy transferred
energy
lost
Energy pyramids compare energy used by producers and other organisms on trophic levels.
Between each tier of an energy pyramid, up to 90 percent of the energy is lost into the atmosphere as heat.
Only 10 percent of the energy at each tier is transferred from one trophic level to the next.

9. Pyramid of Energy

10. A pyramid of numbers shows the numbers of individual organisms at each trophic level in an ecosystem.
tertiary
consumers
secondary
primary
producers 5
5000
500,000
5,000,000
A vast number of producers are required to support even a few top level consumers.

11. Pyramid of Numbers

12. Other pyramid models illustrate an ecosystem’s biomass and distribution of organisms.
Biomass is a measure of the total dry mass of organisms in a given area.
tertiary
consumers
secondary
primary
producers
75 g/m2
150g/m2
675g/m2
2000g/m2

13. Pyramid of Biomass
Biomass refers to the amount of living material found in all the organisms of a specific level.