Ecosystems, Energy, and Matter |
1. |
Describe the fundamental relationship between autotrophs and heterotrophs in an ecosystem. |
2. |
Explain how the first and second laws of thermodynamics apply to ecosystems. |
3. |
Explain how decomposition connects all trophic levels in an ecosystem. |
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Primary Production in Ecosystems |
4. |
Explain why the amount of energy used in photosynthesis is so much less than the amount of solar energy that reaches Earth. |
5. |
Define and compare gross primary production and net primary production. |
6. |
Define and compare net primary production and standing crop. |
7. |
Compare primary productivity in specific marine, freshwater, and terrestrial ecosystems. |
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Secondary Production in Ecosystems |
8. |
Explain why energy is said to flow rather than cycle within ecosystems. |
9. |
Explain what factors may limit production in aquatic ecosystems. |
10. |
Describe an experiment that provided evidence that iron availability limits oceanic primary production in some regions. Explain how iron availability is related to nitrogen availability in these regions. |
11. |
Explain why areas of upwelling in the ocean have exceptionally high levels of primary production. |
12. |
Distinguish between each of the following pairs of terms:
a. primary and secondary production
b. production efficiency and trophic efficiency |
13. |
Explain why the production efficiency of a human is much less than the production efficiency of a mosquito. |
14. |
Distinguish among pyramids of net production, pyramids of biomass, and pyramids of numbers. |
15. |
Explain why aquatic ecosystems may have inverted biomass pyramids. |
16. |
Explain why worldwide agriculture could feed more people if all humans consumed only plant material. |
17. |
Explain the green-world hypothesis. Describe five factors that may act to keep herbivores in check. |
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The Cycling of Chemical Elements in Ecosystems |
18. |
Describe the four nutrient reservoirs and the processes that transfer the elements between reservoirs. |
19. |
Name the main processes driving the water cycle. |
20. |
Name the major reservoirs of carbon. |
21. |
Describe the nitrogen cycle and explain the importance of nitrogen fixation to all living organisms. Name three other key bacterial processes in the nitrogen cycle. |
22. |
Describe the phosphorus cycle and explain how phosphorus is recycled locally in most ecosystems. |
23. |
Explain how decomposition affects the rate of nutrient cycling in ecosystems. |
24. |
Describe how net primary production and the rate of decomposition vary with actual evapotranspiration. |
25. |
Describe the experiments at Hubbard Brook that revealed the key role that plants play in regulating nutrient cycles. |
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Human Impact on Ecosystems and the Biosphere |
26. |
Describe how agricultural practices can interfere with nitrogen cycling. |
27. |
Explain how “cultural eutrophication” can alter freshwater ecosystems. |
28. |
Describe the causes and consequences of acid precipitation. |
29. |
Explain why toxic compounds usually have the greatest effect on top-level carnivores. |
30. |
Describe how increased atmospheric concentrations of carbon dioxide could affect Earth. |
31. |
Describe the causes and consequences of ozone depletion. |
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