Abstract: This study investigated the total concentration and three chemical fractions (exchangeable, carbonate, and organic fractions) of soil metals (Mn, Cr, V, Pb, Ni, Cu, Co and Cd) with simulated nitrogen addition and increased precipitation in a temperate steppe site in Duolun, Inner Mongolia. After nine years of nitrogen addition, increased precipitation and their interaction treatments, no statistically significant effect was observed on the total concentrations of soil metals. Only the concentrations of the exchangeable fraction of Mn, Pb, Ni, Co, and Cd, and the organic fraction of Cr were significantly decreased (P<0.10). In conclusion, longterm nitrogen addition and increased precipitation have limited effect on soil metal concentrations and their chemical fractions. The metalrelated soil environmental quality in the studied semiarid temperate steppe is relatively stable in response to increasing atmospheric nitrogen deposition and precipitation within nine years; however, more attention should be paid to the possible change in the exchangeable fraction of soil metals.

Key words: understory vegetation coverage, environmental factor, Pinus massoniana plantation.