The background concentrations of 13 soil trace elements and their relationships to parent materials and vegetation in Xizang (Tibet), China

The background concentrations of 13 soil trace elements, copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), nickel (Ni), chromium (Cr), mercury (Hg), arsenic (As), selenium (Se), cobalt (Co), vanadium (V), manganese (Mn), and fluorine (F), from approximately 205 pedons in Tibet, China are reported here for the first time. The 13 trace element concentrations follow an approximately log-normal distribution. While the mean concentrations of Hg and Se are lower and As is higher than the average concentration for all of China, concentrations of the other trace elements are similar to the national average. Trace element concentrations are related to vegetation and human activity also played a notable role on the contents of trace elements in Tibet. The parent material relationship for all 13 soil trace element concentrations follows the pattern: shale > sandstone congruent to igneous rock congruent to limestone > alluvial sediment > glacial deposits > lake sediments; while for vegetation and human activity the concentration pattern is farmland = shrub > forests > meadow > prairie > marsh and others. The soil trace element concentrations on the Tibetan Plateau are related primarily to the parent material, but were also affected by vegetation and human activity. (C) 2002 Elsevier Science Ltd. All rights reserved.