Trace metals in forest soils at four sites in southern China

Industrial development has increased fast in China the last decades. This h as led to a range of environmental problems. Deposition of heavy metals to forest ecosystems via the atmosphere is one potential problem. In this pape r we report results from a pilot study where the heavy metal levels in fore st soils at four different sites have been measured. Three of the sites are located relatively close to the large cities Chongqing, Guiyang and Guangz hou; one site is located in a remote, mountainous area in Guizhou province, Total metal contents as well as fractions according to Tessier's scheme we re determined. With a few exceptions, the metal concentrations can be chara cterized as low; i.e. in most cases within the range of what has been repor ted as typical background values in the literature. High content of arsenic (up to 100 ppm) was found in the samples from the site outside Guangzhou, most likely due to naturally high arsenic levels in the soil. Metals bound to organic matter and to iron- and manganese oxides were the dominant fract ions. No clear differences in metal levels were found between topsoil and s ubsoil samples, indicating that the atmospheric deposition of heavy metals has been low.