Biogeochemistry, defined

Vegetation has been classified into a number of reaction types (Ernst, 1993). Within the group of plants that react to their environment (reactors), those with visible (or overt) reactions can be distinguished from those with non-visible (or covert) reactions. In the case of geobotany as defined by Ernst (1993), visibility means to the unaided human eye, that is colour, morphology, presence, abundance or absence of species. Cole has pointed out (Cole and Smith, 1984) that is was not until about 1945, when rapid routine methods of analysis for large numbers of samples became available, that biogeochemistry, that is the study of the chemical composition of plants from various habitats, was used for mineral exploration in many parts of the world. 

Similarly, in Canada the natural background is defined as that fraction of ambient metal considered to be dependent on the biogeochemistry of the site, in contrast to the fraction that reflects historical human activity. However, in some areas of the world,... 

The biosphere is defined as the terrestrial and aquatic ecosystems, including the oceans. As mentioned above, microbial processes have a strong, in many cases controlling, influence on the biogeochemistry of nitrogen in these systems. These processes themselves constitute a cycle (Figure 1). The individual processes are briefly defined below. 

Present a definition of environmental biogeochemistry and define the process of environmental pollution from a biogeochemical point of view. 

Biogeochemical cycles are defined in part by the chemical elements present and their distribution in various parts of the Earth. This chapter describes how the elements that made up the solar nebula were formed. The condensation and differentiation of the elements within the nebula to form the planets are then outlined. These processes gave Earth the inventory of elements that begin to define its biogeochemistry. 

In order to define the research field of this newly created science, Vernadsky introduced his interpr ation of the term the biosphere. He had used the term biosphere siiKe 1911, but first gave a clear definition in 1923, after the beginning of his synthetical works in biogeochemistry (Vassoevich, Ivamiv, 1977, p. 69, Vernadsky, 1923, pp. 38-39). The biosphere of the Earth appears as one of the geospheres occupied and organised by life and thus can be seen as a geological envelope. 

One can also approach this question fi-om a rather morphological viewpoint, something Vernadsky defined as. .secondary" in his theory of biogeochemistry. It was along these lines, though, that a younger contemporary of Vernadsky, V. N. Beklemishev (1890-1962), created a detailed theory of the biosphere as a living system. The attention of historians of science had already been drawn to the necessity of a comparative analysis of these two theories (Svetlov, 1994). 

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