Trace elements in soils in the northern and the central Tian-Shan (Kazakhstan - Kyrgyzstan)

The paper examines and compares heavy metal contents in soils from two altitudinal sequences in the northern and the central Tian-Shan mountains (Kazakhstan and Kyrgyzstan). The soil horizons of 11 sites were described, sampled, analysed, interpreted and classified. Results show that pedological processes similar to those responsible for the development of steppe chernozems are active even at very high elevations. This is probably in part due to the presence of blankets of aeolian silt deposited recently and in the past. In order to verify the degree of accumulation and possible ecotoxicity, the distribution and mobility of Cd, Cr, Cu, Zn, Pb, and Ni within soil profiles were checked. Relationships among elements and other pedological parameters, such as organic carbon content, pH, texture, etc., were investigated. Lastly, the possible risk of contamination was assessed.