Variability of heavy metal content in soils of typical Tibetan grasslands

Abstract

Relatively high contents of heavy metals were recently reported in the high-altitude Tibetan Plateau (TP) environment, but the source and distribution characteristics of heavy metals in grassland environments of the TP remain unclear. Here, we report the contents of Hg, Cd, As, Pb, Ni, Cr, Cu, and Zn in soils of typical grasslands from the western to eastern parts of the TP, and the factors regulating accumulation of these heavy metals in the soil. Results show a large degree of variability of the eight heavy metals in the topsoil (0-20 cm) of different grasslands of the TP. Distribution characteristics of the heavy metals in the subsoil (20-40 cm) from the different grasslands were similar ..