ABSTRACT
Two peatlands in central part of Kirov region (Zenginsky and Karinsky) are investigated. During three field seasons, soil profiles were made and peat samples by layers were collected. The content of total and mobile forms of zinc (Zn), copper (Cu), lead (Pb), and cadmium (CD) were determined by method of an inversion volt-amperemetry. It is revealed that content of the studied elements in general does not exceed average values for various soil types of area. On light-drained undeveloped part of a Zenginsky peatland, the content of total Zn in different profile layers varied from 0.16 to 2.60 mg/kg, mobile—from trace values to 1.60 mg/kg. The content of Cu changed from trace values to 0.90 mg/kg for total and up to 0.12 mg/kg for mobile forms. The content of total Pb fluctuated from 0.37 to 5.60 mg/kg, mobile forms—from trace to 2.90 mg/kg (Fig. 1.1). The low content of Cd is noted (up to 0.59 mg/kg of total and 0.038 mg/kg mobile). Biogenous and accumulative type of accumulation in top layers of peat deposit is accurately traced for all four elements. Development of a peatland led to change in content and redistribution of chemical elements in newly formed profiles. The content of total Cu varied from trace values 4up to 34.00 mg/kg; Zn—up to 126.00 mg/kg, in the lower mineral part of a profile—up to 40.00 mg/kg. The content of total Pb in profiles varied from trace values up to 17.00 mg/kg; the content of mobile forms did not exceed 2.30 mg/kg. Content of total Cd did not exceed 1.00...1.20 mg/ kg on average. Nevertheless, on some sites concentration of an element in separate layers reached 4.41...8.60 mg/kg. Content of mobile Cd is noted as trace. Residual layers of peat of the Karinsky peatland were also characterized by the insignificant content of heavy metals. Content of total Zn varied within 4.20...62.00 mg/kg, mobile form—from trace up to 1.46 mg/kg. Content of total Cu made 3.70...22.0 mg/kg, mobile forms—up to 0.69 mg/kg. Content of total Pb changed from trace values up to 4.10 mg/ kg; mobile forms had trace concentration. Content of total and mobile Cd did not exceed 1.90 mg/kg. The botanical composition of peat substantially influenced the content of chemical elements: it is revealed accumulation of the studied metals in layers with prevalence of wood remains—B. pubescens Ehrh., P. sylvestris L., and P. abies (L.) H. Karst. as well as Typha sp. and Phragmites sp. Economic use leads to an active mineralization of the top part of the remained peat mass. Profiles of the developed peat bogs are characterized by considerable fluctuations in content of heavy metals both in different profiles, and in the different horizons of the same profile. These facts indicate occurring of reorganization of soil processes and modes in the developed and drained soils.
