Information-Modeling Technology for the Environmental Monitoring - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 66

Fig. 1.32 Reserves, fluxes, and cycling times of nitrogen in the atmosphere-biosphere-geosphere

system (Harrison et al. 2005; Vitousek 2004). Notation Pt = 10 15 tons, Tg = 10 12 g, Gt = 10 9 tons

fl

such as cation, assimilation, and dissimilation. The

structural schemes of these processes have been described in detail by many
authors. Their complexity level is determined by the goal of studies, availability of
data on the rates of transformation of the nitrogen-containing compounds and their
supplies, by the level of detailing, etc.
Nitrogen moves in the biosphere by a complicated meandering structure of

fixation, mineralization, nitri

fl fluxes consisting of a hierarchy of cycles at various levels of life organization. From

the atmosphere, nitrogen enters the cells of microorganisms, from which it goes to
soil and then to higher plants, animals, and humans. Dying off of living organisms
results in the turn of nitrogen to the soil, from which it is either consumed by plants
and living organisms or is emitted to the atmosphere. About the same scheme of
nitrogen oxide cycling is inherent to the hydrosphere. The characteristic feature
of these cycles is their openness connected with the available processes of removal
of nitrogen from the biospheric balance into rocks, from where it returns much
slower. Taking into account the nature of the nitrogen cycle in the biosphere and its
reservoir structure enables one to formulate a global scheme of nitrogen

uxes.
To simplify the calculation scheme presented in Fig. 1.35 , advection processes in
the balance equations of nitrogen cycle can be described by a superposition of the
fl

fl

uxes H 14 and H 15 . The computer realization of these equations introduces into
them some corrections for the agreement between the dimensionalities of the