Content and Mobility Metals in Oligotrophic Peat Soils of the Cryolithozone of Western Siberia

Abstract

The ongoing climatic changes have the greatest impact on natural ecosystems in high-latitude areas, as warming climate, as well as increasing anthropogenic load associated with the development of Arctic zone, contribute to the degradation of frozen peatlands and an increase in the thickness of seasonally thawed layer of soil. The relevance of studying peat oligotrophic soils (Cryic Histosols) of the northern territories of Western Siberia is associated with the fact that their degradation enriches natural waters by organomineral substances, which containing a large number of chemical elements, including heavy metals, contributing to changes in the hydrogeochemical properties of natural waters of the North. The article describes the main properties of peats sampled from different horizons of soil profiles laid down at key areas covering the territory of YNAO from north to south and from west to east. The chemical composition of soils was analyzed at the IPA SB RAS using standard methods. The concentrations of gross and mobile forms of metals (Fe, Ca, K, Na, Mg, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) were investigated by optical atomic emission spectrometry and flame atomic absorption spectrometry, respectively. It has been determined that a characteristic feature of the distribution of concentrations of chemical elements in peat oligotrophic soils of the northern part of Western Siberia is the presence of two maxima within the soil profile. The first is confined to the upper horizons showing signs of degradation, while the second is confined to the upper part of the permafrost. Statistical analysis using principal component method showed that low ash content, pH and C/N ratio are associated with high mobility of K, Cu, Zn and Mg. The mobility of Fe, Mn, Pb, Cd, and Cr is associated with an increase in ash content, pH, and Ntotal in the upper part of permafrost organogenic rocks.