Soils chemical composition

Compare the biological and biogeochemical characteristics of Tundra and Polar ecosystems. Explain the role of climate and soil chemical composition in the formation of biogeochemical turnover in Tundra ecosystems. 

Soil analysis is usually aimed at evaluating its agricultural characteristics. The soil chemical composition is very diverse and the definition of pollutants in soil, natural as well as anthropogenic, depends on the soil type, locality and also on the composition assumed to be normal . The comparison with assumed normal levels of particular components is achieved by using standard samples of soils, or of similar soils from a different region. Standard soil samples are not commonly available and thus, the second... 

Soil moisture is important characteristic for passing of ontogerty stages by organism from the moment of seed germination. Moreover, this oharacteristie has immediate impact on soil chemical composition because of having inflnence on transition of chemical elements from immobile forms to mobile. 

The final composition of stream water is the product of the weathering reactions and related processes outlined above. However, the chemical processes are influenced and controlled by an intricate combination of environmental factors that are characteristic for each drainage system. Therefore, the composition of the bedrock in an area and the residual material left at the surface as soil and subsoil exert a strong influence on the chemical composition of mnoff from the area. The reactions of water with this material are the ultimate geological control and are the source of soluble weathering products. 

This will depend upon the type and quality of soil and its chemical composition, i.e. the composition of salts and minerals, content of moisture and normal rainfall during the year. Table 22.1 obtained from BS 7430 and Table... 

The combined influences of runoff generation mechanisms, runoff flowpaths, and soil properties together control runoff chemistry. In spite of the wide range of interactions that characterize terrestrial environments, a few broad generalities can be offered, as the chemical composition of streamflow typically contains... 

The acidity of soils also strongly affects the availability of metal cations such as K, Mg, and Ca. Most soils contain significant amounts of clay, whose chemical composition is dominated by aluminosilicates. Silicates are anionic, and the anions can be neutralized either by accepting protons or by associating with metal cations. When soil is too acidic, protons replace these metal cations, and the soil becomes depleted in these essential nutrients. 

As baghouse dust accounts for a minimum of the total foundry solid waste, less attention is placed on characterizing this wastestream. Few data are available giving its physical properties and chemical composition. Visually, it is a very fine powder, dark gray in color. The dust may demonstrate physical properties that are similar to clay soils. 

The chemical composition of the soil and groundwater, specifically the amount of natural organic matter (NOM) and other reduced species, such as iron (II) or manganese (II) often analyzed as the chemical oxygen demand (COD) of the soil, or the soil oxidant demand. 

Over 98% of the soil is made up of only eight major chemical elements, listed in Table 51, in order of decreasing abundance. The 90-odd others make up the remaining 2% many occur in the soil as secondary or minor elements, while a large number of still others are present in only very low, often trace, concentrations. Thus all soils contain main, minor, and trace elements combined into chemical compounds and aggregated into complex particles of varying shape, size, and chemical composition (see Textbox 8). 

Leinweber P, Schulten HR, Korschens M (1995) Hot water extracted organic matter chemical composition and temporal variations in a long-term field experiment. Biol Fertil Soils 20 17-23... 

Soils have to be dried under controlled conditions so as to avoid changing their chemical composition. You should remember that microbial activity can affect the levels of some analytes, such as phosphorus and potassium. 

Table 2. Chemical composition of soils in Australian Tropical Rain Forest ecosystems (after Congdon and Lamb, 1990, see Bashkin, 2002).

The biodiversity of Mangrove ecosystems is the most profound in the islands and coastline of the Indo-West-Pacific region, where the occurrence of 44 varieties has been reported. On the Atlantic Ocean coast Mangrove ecosystems are especially widespread in the Caribbean region. The chemical composition of plant species and soils of Mangrove ecosystems have been recently discussed (Dobrovolsky, 1994). 

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