1. FLOWS OF ENERGY AND MATTER 2.3

2. Energy Budget:

3. Boxes and Circles represent Storage and Arrow thickness represents magnitude of flow Only a very small part of the total sunlight reaching the Earths surface is ever transformed into energy used by living organisms. A study of an Illinois cornfield suggested only 1.6% was actually used by the corn.

4. Pathways of radiation through ecosystem ■Conversion of light energy to chemical energy ■Transfer of chemical energy from one trophic level to another (efficiency varies) ■Overall conversion of ultraviolet and visible light to heat energy by organisms in ecosystem ■Re-radiation of heat energy to the atmosphere

8. Energy currency: C-H bonds photosynthesis respiration

12. Summary: ■Energy is conserved in ecosystems –First law of Thermodynamics ■Chemical energy used by “buffalo and bacteria” must be less than the chemical energy generated via primary production, due to unavoidable inefficiencies in energy capture. ■Photosynthesis is the dominant source of energy in most ecosystems through conversion of light to C-H bonds in organic material.

13. Summary: ■The flow and fate of carbon is tightly linked to energy flow. ■This fact is fundamental to understanding how carbon and energy flow are –linked to other elements and nutrients –support patterns of biodiversity –connect carnivores, herbivores, and plants

14. Work Cited ■Beman, J. (2010) Energy Economics in Ecosystems. Nature Education Knowledge 3(10):13