Biogeochemical peculiarities

The Caspian Sea is the largest inland water body on earth (386,400 km2, maximum depth 1025 m). With its long history of oil and industrial development, the Caspian is often regarded as severely polluted and ecologically degraded. The North Basin of the Caspian Sea is a large (25% of the Caspian Sea surface area), shallow (median 

Concentrations of V, Mn, Fe, Cr, Co, Cu, Zn, As, Se, Mo, Ag, Cd, Tl, Hg, Pb, and organic mercury (Org-Hg) were determined in liver, kidney, and muscle of healthy Caspian seals (Phoca caspica) collected in 1998. These concentrations were compared with those of seals infected with canine distemper virus (CDV) found stranded along the coastal areas in 2000 (Table 1). Concentrations of toxic elements (As, Ag, Cd, Tl, Hg, Pb, and Org-Hg) in Caspian seals stranded in 2000 were comparable or lower than those of samples collected in 1998 and in other pinnipeds. Thus it may be inferred that these elements were not the causative agents in the deaths of the seals. In contrast, concentrations of Zn and Fe were much higher in diseased Caspian seals than those in other pinnipeds. Zinc concentrations in all tissues of Caspian seals also increased during 1993-2000. Furthermore, negative correlations were found between blubber thickness and hepatic and renal Zn concentrations. These results imply the disturbance 

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We can see from Figure 3 that the moderate deficit of I, Co, Zn, Cu, Mo, B, and Mn with optimal ratios of trace metals to I and Si, is characteristic for all links of a biogeochemical food web. These biogeochemical peculiarities favor the optimal physiological regulation of exchange processes in animal and human organisms. However, a moderate deficit of essential trace nutrients weakens the human immune... 

The statistical estimation of heavy metal concentrations in the Spruce Forest ecosystems of the Boreal climatic zone is the subject of wide variation, with coefficient of variation from 36 to 330%. However, we can note the clear trend in biogeochemical peculiarities and relevant exposure to heavy metal uptakes by dominant plant species. 

The various steppe plant species indicate the individual biogeochemical peculiarities related to pollutants exposure. For example, we can discuss the results from the South... 

Many quantitative aspects of exposure pathways and their relevant application during environmental risk assessment depend on regional biogeochemical peculiarities and should be undoubtedly considered on the regional scale. Accordingly this part includes some characteristic examples and case studies from local up to regional and continental dimensions. We discuss the importance of the trans-boundary of pollutant exposure as well as the application of critical load methodology for risk estimates. 

Evstafyeva, E. V. (1996). Physiological and Biogeochemical Peculiarities of Adaptation in Various Environments. DrSc Thesis, Moscow University of Volk Friendship, 32 pp. 

The natural biogeochemical peculiarities (see Chapter 4, Section 4 and Chapter 6, Section 4), which favor the development of endemic diseases were complicated by anthropogenic activity. In the area of the Volga-Ural watershed and the Ustyurt plateau, this activity is connected with oil explorations and oil-chemical industry. The watershed of Amu-Daria and Syr-Daria rivers is the agricultural area with intensive irrigated cotton production with application of heavy rates of pesticides and fertilizers. 

Using the above-mentioned approaches, we may describe the peculiarities of biogeochemical structure for the main global ecosystems in various continents. Detailed... 

BIOGEOCHEMICAL AND PHYSIOLOGICAL PECULIARITIES OF HUMAN POPULATION HEALTH... 

The deficit of I, Co, Mn, and Zn, moderate excess of Si and disturbed ratios of trace metals to I and Si are characteristic features of the biogeochemical food web of this Pre-Volga sub-region of biosphere. Most of its natural water sources have a decreased content of fluorine. These peculiarities of biogeochemical food web favor the occurrence of tooth decay (caries) and endemic goiter. 

GEOGRAPHICAL PECULIARITIES OF BIOGEOCHEMICAL CYCLING AND POLLUTANT EXPOSURE... 

Table 3 presents the averaged data for the whole forest area of Boreal and Sub-Boreal zone. However, there are definite peculiarities of biological and biogeochemical cycles in the individual ecosystems. We will consider the Spruce Forest ecosystem of the Karelia region, Russia. These ecosystems occur in the wide area of the Karelia, south from 63° N. 

These peculiarities of urban area development led to the technogenic biogeochemical provinces, i.e., the areas with local increase of pollutants in different components of urban ecosystems such as soils, grounds, surface and ground waters, plants, atmosphere. These pollutants create ecological risk to human and ecosystem health by their accumulation in the biogeochemical food webs (food stuffs and water). 

In the ecosystems of the Asian part of Russia the values of critical loads for N, CL(N), and S, CL(S), compounds are shown to be less than in Europe due to many peculiarities of climate regime (long winter with accumulation of pollutants in snow cover) and depressed biogeochemical cycling of elements (see section 1). The minimum values of both CL(N) and CL(S) are <50 eq/ha/yr and the maximum ones are >300 eq/ha/yr (Figures 15 and 16). 

Here we will describe the main features of the Black Sea biogeochemical structure from the point of view of the changing of redox conditions. We will also analyze the main peculiarities of the seasonal and interannual variability of this structure primarily on the base data received in 1997-2006. The main attention we will placed on describing the structure and temporal variability of the chemical structure of the redox layer, the boundary layer between oxic and anoxic waters. 

Discuss the main peculiarities of carbon biogeochemical evolution. Present the isotopic record of this evolution in various fossil rocks. 

The spatial heterogeneity of selenium content in rocks, various soils, and especially the peculiarities of its translocation from soils to plants, lead to the formation of so-called selenium biogeochemical provinces (see Chapter 7 Biogeochemical mapping ). These provinces are characterized by a deficient or excessive concentration of this trace metal in all links of biogeochemical food webs. Selenium deficiency in fodder crops is related to the less than 30 ppm content of this element (Table 8). This leads to myopatia (white colored animal tissues), necrotic degeneration of kidney, exude diathesis. The addition of sodium selenite is used for prevention of these diseases. 

Discuss the interactions of biogeochemical cycles in microbial mats in aquatic ecosystems. Discuss the peculiarities of individual cycles of C, S, and N, and their interactions in microbial mats. 

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