Biogeochemical cycles carbon

Smith S.V. and Mackenzie F.T. (1987) The ocean as a net heterotrophic system Implications from the carbon biogeochemical cycle. Global Biogeochem. Cycles 1, 187-198. 

Verrecchia, E. P. (1990). Litho-diagenetic implications of the calcium oxalate-carbonate biogeochemical cycle in semiarid calcretes, Nazareth, Israel. Geomicrobiology Journal, 8, 87-99. 

In the atmosphere CO2 is affected by processes that operate at different time scales, including interaction with the silicate cycle (see Chapter 2), dissolution in the oceans, and annual cycles of photosynthesis and respiration (see also Section 3). The relative effect of these processes is described below in the consideration of the whole carbon biogeochemical cycle and environmental aspects of biogeochemistry. Here, it is important to note that carbon dioxide is not reactive with other atmospheric species its MRT is 3 years (Figure 4). This value is largely determined by exchange with seawater (see Section 2). 

The interaction between carbon dioxide in the atmosphere and the hydrosphere is the principal factor for understanding large carbon biogeochemical cycles. As it has been mentioned above, the gases of the troposphere and the surface layer of the ocean persist in a state of kinetic equilibrium. 

What would be the consequences of man-made disturbance of the natural carbon biogeochemical cycle Choose an example and present a biogeochemical explanation. 

Substrate-induced respiration appears to be a less sensitive indicator of TNT impacts on the carbon biogeochemical cycle compared with the measurement... 

Apparently, there are many studies about the distribution, content, transfer, and transformation of carbon in sediment or soil to be performed. As one of three interdependent basic links in sediment (including soil-water-atmosphere systems), marine sediment plays an important role in oceanic or global environments. From now on, more attention should be paid to research into the functions of sediments in carbon biogeochemical cycles (Sun and Song, 2002). 

Feedbacks may be affected directly by atmospheric CO2, as in the case of possible CO2 fertilization of terrestrial production, or indirectly through the effects of atmospheric CO2 on climate. Furthermore, feedbacks between the carbon cycle and other anthropogenically altered biogeochemical cycles (e.g., nitrogen, phosphorus, and sulfur) may affect atmospheric CO2. If the creation or alteration of feedbacks have strong effects on the magnitudes of carbon cycle fluxes, then projections, made without consideration of these feedbacks and their potential for changing carbon cycle processes, will produce incorrect estimates of future concentrations of atmospheric CO2. 

An important example of non-linearity in a biogeochemical cycle is the exchange of carbon dioxide between the ocean surface water and the atmosphere and between the atmosphere and the terrestrial system. To illustrate some effects of these non-linearities, let us consider the simplified model of the carbon cycle shown in Fig. 4-12. Ms represents the sum of all forms of dissolved carbon (CO2, H2CO3, HCOi" and... 

Just as in the case for the hydrosphere, the atmosphere participates in all of the major biogeochemical cycles (except for phosphorus). In turn, the chemical composition of the atmosphere dictates its physical and optical properties, the latter being of great importance for the heat balance of Earth and its climate. Both major constituents (O2, H2O) and minor ones (CO2, sulfur, nitrogen, and other carbon compounds) are involved in mediating the amounts and characteristics of both incoming solar and outgoing infrared radiation. 

Stallard, R. F. (1998). Terrestrial sedimentation and the carbon cycle Coupling weathering and erosion to carbon burial. Glob. Biogeochem. Cycles 12, 231-252. 

Archer, D., Peltzer, E. T. and Kirchman, D. (1997). A timescale for dissolved organic carbon production in equatorial Pacific surface waters. Glob. Biogeochem. Cycles 11,435-452. 

Apart from CO2, CH4, and CO there are many gases containing carbon present in the atmosphere, terpenes, isoprenes, various compovmds of petrochemical origin and others. We will not discuss them further, although some, like dimethylsulfide (DMS, (CH3)2S), are of great importance in the biogeochemical cycles of other elements. The total amount of atmospheric carbon in forms other than the three discussed is estimated at 0.05 Pg C (Freyer, 1979). 

Pollard, D., Sitch, S. and Haxeltine, A. (1996). An integrated biosphere model of land surface processes, terrestrial carbon balance, and vegetation dynamics. Global Biogeochem. Cycles 10, 603-628. 

Hunt, E. R. Jr., Piper, S. C., Nemani, R., Keeling, C. D., Otto, R. D. and Running, S. W. (1996). Global net carbon exchange and intra-annual atmospheric CO2 concentrations predicted by an ecosystem process model and three-dimensional atmospheric transport model. Global Biogeochem. Cycles 10, 431-456. 

Kindermann, J., Wiirth, G., Kohlmaier, G. H. and Badeck, F.-W. (1996). Interannual variations of carbon exchange fluxes in terrestrial ecosystems. Global Biogeochem. Cycles 10, 737-755. 

C. J. and Schloss, A. L. (1997). Equilibrium responses of global net primary production and carbon storage to doubled atmospheric carbon dioxide Sensitivity to changes in vegetation nitrogen concentration, Global Biogeochem. Cycles 11,173-189. 

Post, W. M., King, A. W. and Wullschleger, S. D. (1997). Historical variations in terrestrial biospheric carbon storage, Global Biogeochem. Cycles 11, 99-109. 

Randerson, J. T., Thompson, M. V., Conway, T. J., Fung, I. Y. and Field, C. B. (1997). The contribution of terrestrial sources and sinks to trends in the seasonal cycle of atmospheric carbon dioxide. Global Biogeochem. Cycles 11,535-560. 

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