Energy Flow and Chemical Cycles

2. Energy Flow and Chemical Cycles

3. Objectives • Discuss energy flow through different ecosystems • Trace cycles of Carbon, Nitrogen, and water

4. Ecosystem All the energetic interactions and material cycling that link organisms in a community with one another and with their environment

5. Energy and Production

6. Energy is not created or destroyed. It changes form and place When energy changes form some of it is lost as entropy (heat) Laws of Thermodynamics

7. Production

8. Species efficiency Efficiency = NPP/GPP Corn .85 Deciduous trees .42 Prairie grass .66 Physical environment Water Heat Difference in productivity

9. Secondary ProductionAnimals Energy, once consumed goes to maintenance, and waste. Little is left for production. 10% rule .

10. Homeotherms High assimilation, high metabolism, thus low production efficiency

11. Poikilotherms Low metabolism, low assimilation, thus even lower production efficiency

12. Food Chains and Food Webs

13. Food Chain– series of steps by which energy stored in plants is passed through an ecosystem Fig. 5.14 Definitions

14. Definitions • Food web – several interrelated food chains Fig. 5.15

15. Components • Producers – plants • Herbivores – convert plant tissue into animal tissue • Carnivores – eat other animals, levels • Omnivores – eats both plants and animals

16. Components • Scavengers – animals that eat dead plant and animal matter • Saprophytes – plant and fungi that absorb dead material • Decomposers – everything is a decomposer

17. Biophages – use living matter Saprophages – use nonliving matter Another way of viewing energy relationships(Heterotrophs)

18. Grazing food chain – energy flows through the biophages Detrital food chain – energy flows through the saprophages. Fig. 23.3 Fig. 23.4 Fig. 23.5 Two Major Food Chains

19. Chemical Cycles

20. Water cycle • Fig. 16.3

21. Water Cycle

22. Carbon Cycle • Fig 5.16

23. Carbon Cycle

24. Nitrogen cycle • Fig. 5.17

25. Nitrogen cycle

26. The End Have a good weekend!