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  • Essay / Soil Composition Research - 782

    As described above, Quaternary glacial, glaciofluvial and alluvial deposits are absent but may occur in protected landform positions. The main soil-forming materials are the ubiquitous Triassic trapean rocks. According to Sokolov et al. (2002), the soils of this province develop mainly from residues of rocky substrates or their loose derivatives of collluvial and solifluctional origin. In general, the mineral and chemical composition of “sedimentary mantles” resembles the underlying bedrock (Sokolov et al., 2002). Due to low thermal regimes, chemical weathering is hampered, while physical and cryopedogenic processes dominate soil genesis. Cryopedogenic processes that lead to gel materials according to USDA (2009) mainly based on the change in physical volume of water to ice by 9% and vice versa. Additionally, on thermal contractions of frozen materials by continuous cooling and moisture migration in a frozen system along a thermal gradient (Bockheim et al., 1997). In addition to cryopedogenic processes, Sokolov et al. (2002). (1) Braunification leads to primitive soils with weak and shallow cambic horizons described in Sokolov et al. (2002) described as typical pale soils (from Russian Palevye). In soil taxonomy, they have a haplic epipedon, not to be confused with the prefix Pale in nomenclature. They have a relatively homogeneous profile with almost no vertical difference in texture, resulting from development from colluvial or solifluction deposits. Usually pale soils are covered with a layer of raw humus. (2) Podsolization, a top-down relocalization of low molecular weight organomineral compounds (chelates; Al-Fe-humus complexes) in acidic soils due to hindered microbial turnover (Scheffer und Schachtschabel, 2002). ...... middle of article ...... is generally the lack of nutrients in soils of northern ecosystems and the key determinant of C stocks, sequestration and growth rates of the vegetation. The short growing season at high latitudes also favors the accumulation of C and N rather than their turnover. Following Walker (1996), we can summarize the mechanisms controlling element movement and nutrient cycling in permafrost-affected soils as: "(1) the characteristics of the parent materials and alteration. prices; (2) migration of water and heat during freezing; (3) the biotic components present in the vegetation cover and the relative rates of production and decomposition; (4) enzymatic activity rates of soil organisms; (5) vertical and horizontal movement of water in the soil during the growing season'. The interaction of the described factors controls the processes of primary production and turnover, which, in turn, affect the dynamics of C..