Content of heavy metals (Zn, Pb, Cu and Cd) in peat and plants of cutover peatlands

Abstract

Two peatlands in the central part of the Kirov region (Zengino and Karino) were investigated. During three field seasons, soil profiles were compiled and peat samples by layers were collected. The content of total and mobile forms of zinc, copper, lead and cadmium was determined by inversion voltammetry. The content of the studied elements does not exceed the average values for various soil types of the region. Development of the peatland led to a change in the content and redistribution of chemical elements in the newly formed profiles. The botanical composition of peat is substantially related to the content of chemical elements: the accumulation of metals in layers with prevalence of wood remains was revealed. Economic use leads to active mineralization of the top part of the remained peat mass. The profiles of developed peatlands are characterized by considerable fluctuations in the content of heavy metals both in different profiles and in different horizons of the same profile. Plants growing on dried peatlands accumulate low doses of the investigated metals that do not exceed standards of maximum allowance concentrations. Rosa majalis accumulate zinc, lead and cadmium in the least degree. The highest concentration of all four elements is found in the leaves of Salix caprea.