Regularities of formation of mountain-forest soils’ microelement composition of western caucasus

Abstract

Purpose of work. Identification of the features of the mountain soils microelement composition formation under the forest vegetation of the Western Caucasus with a homogeneous nature of soil-forming rocks.. Research мethods: The determination of the microelement composition of mountain soils was determined in the Teberda Nature Reserve, in the upper part of the Teberds river basin within the range of Malaya Khatipara. Chemical analysis of the soil is carried out by generally accepted methods. In soils, the content of strongly bound Pb, Cu, Zn, and Cd compounds by acid decomposition using 5 M HNO3 was analyzed. Mobile forms of trace elements are converted into a solution using an ammonium acetate buffer solution. The metal content is determined by voltammetric and atomic absorption methods. Features of the microelement composition of parent rocks are revealed by comparison with clarks of chemical elements in the upper part of the continental crust. The trace element composition of soils is compared with clarks of chemical elements in the soils of the world. Research results. Differences in the microelement composition of brown mountain forest soils formed under different types of forests have been revealed. The trace element composition of soils under fir forests is characterized by large concentrations of Cu, Cd, and Zn; under the pine trees – high Pb levels; under birch stands – relatively low concentrations of Pb and Zn; Soils of beech forests are characterized by minimal concentrations of Cd. Exposure differences in the manifestation of the climatic and biological factors of soil formation are reflected in the features of the microelement composition of soils. Between the content of trace elements in mountain forest brown soils and the distribution of humus, positive correlation relationships of medium strength for Cu, Cd were revealed; weak for Pb. Conclusions. The formation of trace elements is determined in mountain soils by changes in the conditions of soil formation and the intensity of weathering processes – soil formation with the height and exposure of the slopes. The microelement composition of brown mountain forest soils under deciduous forests is strongly transformed in comparison with parent rocks. The influence of the mineralogical composition of parent rocks in a certain way affects the microelement composition of brown mountain forest soils under coniferous forests