Sample Q4 answers

1. C (see Mackenzie Fig 14.7a and think of the “seasonal” biosphere in short video we saw at end of March 28 lecture- seasonal CO₂ shifts are greatest where vegetation experiences the greatest seasonal)

2. A

3. C (formally known as fullerenes, they are also known as “Bucky Balls”)

4. B (about 10% passes on, and about 90% lost)

5. B

6. D

7. C

8. C (Fig. 7.4- technically we did not get to this in lecture, but you are probably ahead in your reading)

9. B

10. D (from one of Al Gore’s AIT clips)

11. D

12. C (for temperature effects alone, although cool-season C3 grasses would have advantages with higher CO₂ levels)

13. C

14. A

15. A (see classnotes for March 26, look at “Global maps” link)

16. C

17. atmosphere, biosphere, oceans, lithosphere (this would include coal, oil, natural gas), soils (Table 7.2; we did not get to this in lecture, but you have probably read ahead)

18. Generally it is conversion of natural ecosystems to other uses such as urban areas (urbanization) or transportation (roads) or reservoirs behind dams (energy, water storage, etc) or agriculture. Deforestation would be an example, which involves conversion of land from forest to agriculture or grazing (or maybe even cities). Also natural grasslands may be changed to agriculture. Usually such changes result in loss of carbon from the ecosystems, but in some cases such as the abandonment of farmland carbon can be increased. This will not be on quiz- we did not get close to this)

19. Living and dead organic matter in tropical forest biomes is dominated by living plant parts (roots, stems, trunks, leaves) with a smaller fraction of dry matter in dead material (litter and soil), whereas dry matter in grasslands is overwhelmingly in dead material (in litter and soils), with a small fraction in living plant parts (review “Figure from lecture” link at the end of the March 23 lecturenotes)

20. Competition for light resources tends to be much greater on land than in water, and on land the best way to compete is to grow fast and tall, above you neighbors. Consequently, a very high investment in plant structural components on land is needed (trunks, stems) as wood, compared to marine biosphere where such structural components are not needed.

21. Non-native species that have entered an area (accidentally or purposely) with the result that they become established and compete with (maybe outcompete) native species. See your notes and my ClassNotes from March 28

22. Dominance of photosynthesis in spring and summer draws down CO2 from the atmosphere, and dominance of respiration returns CO2 to the atmosphere in Fall and Winter. (“seasonal biosphere” is key to where the effect is greatest, as related to question #1).

23. embayment between river and open ocean (like Chesapeake Bay and San Francisco Bay), where salinity is quite variable (usually low near surface and high near bottom). It will be affected by tides and nutrients being washed off the land, and many commercial fish species will spend at least a portion of their life in these highly productive areas. (coral reefs are the “rain forests of the seas”)

24. warmer temperatures could promote geographical expansion of malaria, but reduction of precipitation at lower latitudes could inhibit spread of malaria

25. See March 23 classnotes and Mackenzie

26. NPP=GPP-respiration (see your Mar 26 notes and classnotes and Mackenzie)

27. C3 grasses are “cool-season” grasses, and C4 grasses are “warm season” grasses. Invasive C3 grasses may gain a competitive advantage as atmospheric CO2 increases. [Note, many plants worldwide such as trees are C3 plants, but they are not grasses]