Geochemical characteristics of soils in natural and disturbed landscapes of the Tunka basin

Abstract

The paper evaluates the distribution of chemical elements in the soil of the Tunka basin (the Republic of Buryatia, Tunka National Park). In this regard, we studied their gross concentration in natural and agrogenically transformed soils: arable land, fallow lands, hayfields, and pastures. The distribution of chemical elements in the soils of the Tunka basin is extremely uneven, except for Fe, Al, Mg, P, Sr, Zn, and Co. The concentrations of chemical elements, as a rule, do not exceed standard values, except for Cr, Ni and Pb. Opposite patterns characterize the nature of the interaction of mercury with chemical elements of groups of different geochemical classifications, depending on the degree of anthropogenic load. In natural soils, the concentration of mercury increases with an increase in the concentration of silicon and phosphorus and a decrease in other heavy metals: Fe, Pb, Cu, Co, Ti, Ni, V, Cr, as well as aluminum and magnesium. In disturbed soils, Hg is directly proportional to all of the above elements other than manganese. The change in the content of most of the studied chemical elements with depth in natural soils decreases with depth. In disturbed soils, there is no such tendency due to mixing of the soil layer in the upper 50 cm layer due to the use of land for arable land.