2. Lindeman 1942

12. External energy source PRIMARY PRODUCERS CONSUMERSDECOMPOSERS ABIOTIC ENVIRONMENT Figure 51.1

13. Figure 54-14 THE GLOBAL CARBON CYCLE Organisms, chemical processes in ocean: 40,000 All values in gigatons of carbon per year Atmosphere: 778 (during 1990s) Net uptake via photosynthesis by plants: 3.0 Net uptake via photosynthesis, chemical processes: 1.5 Rivers (erosion): 0.8 Organisms, soil, litter, peat: 2190 Aquatic ecosystems Terrestrial ecosystems Human-induced changes Land-use change (primarily deforestation): 1.6 Fossil-fuel use: 6.3

14. Land use Fossil fuel use Year Annual flux of carbon (10 15 g) 65432106543210 1860188019001920194019601980 Figure 51.12a Human-induced increases in CO 2 flux over time

15. http://commons.wikimedia.org/wiki/File:Mauna_Loa_Carbon_Dioxide-en.svg

18. <35 35–55 55–90 >90 Productivity ranges (g/m 2 /yr) Figure 51.3b Marine productivity

19. 0–100 100–200 200–400 400–600 600–800 >800 Productivity ranges (g/m 2 /yr) Figure 51.3a Terrestrial productivity

20. Figure 54-2 0 Net primary productivity (kgC/m 2 /year) 3 2 1

21. Figure 54-3 NPP per unit area Area covered, by ecosystem type Total NPP Terrestrial Aquatic

24. Figure 54-16 THE GLOBAL NITROGEN CYCLE Nitrogen-fixing cyanobacteria: 15 All values in gigatons of nitrogen per year Atmospheric nitrogen (N 2 ) Protein and nucleic acid synthesis Bacteria in mud use N-containing molecules as energy sources, excrete N 2 : 310 Decomposition of detritus into ammonia Internal cycling: 1200 Industrial fixation: 100 Lightning and rain: 3 Internal cycling: 8000 Permanent burial: 10 Runoff: 36 Mud Nitrogen-fixing bacteria in roots and soil: 202