1. 1 Energy Flow in an Ecosystem Three hundred trout are needed to support one man for a year. The trout, in turn, must consume 90,000 frogs, that must consume 27 million grasshoppers that live off of 1,000 tons of grass. -- G. Tyler Miller, Jr., American Chemist (1971)

2. 2 Energy Flow Energy in an ecosystem originally comes from the sun Energy in an ecosystem originally comes from the sun

3. Energy Pyramid 2 nd 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.

4. Sample Energy Pyramid

5. 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 (growth, walking, running, etc.) or it is lost to the environment (undigested food becomes feces, bones, etc.).

6. 6 Other Ecological Pyramids Biomass Pyramid Biomass Pyramid : A pyramid of biomass is a representation of the amount of energy contained in biomass, at different trophic levels for a given point in time. (biomass is the dry weight of organic material) Pyramid of Numbers Pyramid of Numbers : represents the number of organisms in each trophic level copyright cmassengale

7. 7 Biomass Pyramid copyright cmassengale

8. 8 Pyramid of Numbers copyright cmassengale