Soils biogeochemical cycles

Biomass Redistribution Associated with Deforestation and Fire. The influence of deforestation on biogeochemical cycles is dependent upon a number of factors associated with the unique characteristics of the ecosystem (climate, soils, topography, etc), the quantity of the total nutrient pool stored in aboveground biomass (Table II), and the level of disturbance (i.e. the degree of canopy removal, soil disturbance, and the quantity of wood or other forest products exported from the site). The quantity of biomass consumed by one or more slash fires following deforestation can also dramatically increase nutrient losses, influence post fire plant succession, and hence, postfire biogeochemical cycles. 

The soil may represent a thin film on the surface of the Earth, but the importance of soils in global biogeochemical cycles arises from their role as the interface between the Earth, its atmosphere, and the biosphere. All terrestrial biological activity is founded upon soil productivity, and the weathering of rocks that helps to maintain atmospheric equilibrium occurs within soils. Soils provide the foundation for key aspects of global biogeochemical cycles. 

We assume that our readers have a background in science attainable by completing a university level course in introductory chemistry. We also expect our readers to be involved in one of the disciplines integral to the study of biogeochemical cycles. This includes appropriate subdisciplines of chemistry, biology, and geology, and the sciences that deal with soils, atmospheres, and oceans. 

Denier van der Gon HAC, van Breemen N, Neue HU, Lantin RS, Aduna JB, Alberto MCR, Wassmann R. 1996. Release of entrapped methane from wetland rice fields upon soil drying. Global Biogeochem. Cycl. 1996 10 1-7. 

Guggenberger G, Haider KM (2002) Effect of mineral colloids on biogeochemical cycling of C, N, P, and S in soil. In Huang PM, Bollag J-M, Senesi N (eds) Interactions between soil particles and microorganisms. Impact on the terrestrial... 

Bouwman AF, Boumans LJM, Batjes NH (2002) Emissions of N20 and NO from fertilised fields summary of available measurement data. Glob Biogeochem Cycles 16 1058 Christensen S, Simkins S, Tiedje JM (1990) Spatial variation in denitrification dependency of activity centers on the soil environment. Soil Sci Soc Am J 54 1608-1613 CONCAWE (2006) Well-to-wheels analyses of future automotive fuels and powertrains in the European context. Study of European Council for Automotive R D, EUCAR, European Commission, Brussels... 

Baisden WT, Amundson R, Brenner DL, Cook AC, Kendall C, Harden JW (2002) A multi-isotope C and N modeling analysis of soil organic matter turnover and transport as a function of soil depth in a California annual grassland soil chronosequence. Global Biogeochem Cycles 16 1135. doi 10.1029/2001GB001823... 

The biogeochemical cycling picture is designed to summarize the circulation features in various components of ecosystems such as soil, surface and ground water, bottom sediments, biota and atmosphere (Figure 1). 

Table 1. The values of biogeochemical cycling (C ), active temperature (Ct) and relative biogeochemival (Ct,r) coefficients in various soil-ecosystem geographical regions of the World (Bashkin and Kozlov, 1999). 

Table 3. The ranges attached to biogeochemical cycling data to assess the migration capacity of soil-ecosystem types.

System 13. soil-plant cycle soil-forming geological rocks (I) soil (IV) soil living matter (community of soil organisms) (V, VI, VII) aerosols, atmosphere air (12a, III) plants (VIII) their biological reactions, endemic diseases (VIII). In the complex system 13, the inner relationships and biochemical and biogeochemical mechanisms are shown for natural and agroecosystems. The system 11 and link IX show the ways for interrelation of system 13 with terrestrial animals. 

The regulation of biogeochemical cycles by microbial populations is of most direct importance in the cycling of N, S, P, and C. Most of the ecosystem pool of these elements resides as organic forms in forest floor and mineral soil compartments. These organic complexes are subjected to microbial transformations, which regulate nitrate, sulfate and phosphate ions dynamics and availability. In turn, this influences indirectly... 

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