Nitrogen cycle units

Table 12-2 Fluxes in the global nitrogen cycle (units are Tg N/yr)...

The Royal Society, The Nitrogen Cycle of the United Kingdom A Study Group Report, The Royal Society, London, 1983. 

Fig. 12-2 Partitioning of the various forms of nitrogen in the atmosphere. Units are Tg N. (Reprinted with permission from R. Soderlund and T. Rosswall, The nitrogen cycles. In O. Huntizger (1982). "The Natural Environment and the Biogeochemical Cycles," p. 70, Springer-Verlag, Heidelberg.)...

Figure 1.15 Schematic budget of the global nitrogen cycle in preindustrial times (black) and how it changed as a result of human intervention (red). Fluxes are in units of Tg N year and inventories (bold italics) inTg N. The flux estimates are based on Gruber and Galloway (2008).

Figure 2 Stepwise decomposition of particulate organic nitrogen (PON) in arbitrary units versus time during a dark incubation. Nitrogen is transformed, first to NH4+ by bacterial ammonification and finally to NOa and NOs by the two-step process of bacterial nitrification. These same processes are responsible for the global ocean formation of NOs in the deep sea. These data are the idealized results of pioneering nitrogen cycle investigators, T. von Brand and N. Rakestraw, who unraveled these processes more than 50 years ago.

The addition of an arbitrary unit of nitrogen to the nitrogen cycle in nature is estimated to create an 800-fold flow in N cycling (93). It is no wonder that... 

Royal Society Study Group. 1983. The Nitrogen Cycle of the United Kingdom. London Royal Society. For the study s update see Johnston, A. E., and D. S. Jenkinson. 1989. The Nitrogen Cycle in UK Arable Agriculture. London Fertiliser Society. 

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