title: Altitudinal patterns and controls of trace metal distribution in soils of a remote high mountain, Southwest China.
abstract: The aim of this study is to reveal the effects of regional human activity on trace metal accumulation in remote alpine ecosystems under long-distance atmospheric transport. Trace metals (Cd, Pb, and Zn) in soils of the Mt. Luoji, Southwest China, were investigated along a large altitudinal gradient [2200-3850 m above sea level (a.s.l.)] to elaborate the key factors controlling their distribution by Pb isotopic composition and statistical models. The concentrations of Cd, Pb, and Zn in the surface soils (O and A horizons) were relatively low at the altitudes of 3500-3700 m a.s.l. The enrichment factors of trace metals in the surface soils increased with altitude. After normalization for soil organic matter, the concentrations of Cd still increased with altitude, whereas those of Pb and Zn did not show a clear altitudinal trend. The effects of vegetation and cold trapping (CTE) (pollutant enrichment by decreasing temperature with increasing altitude) mainly determined the distribution of Cd and Pb in the O horizon, whereas CTE and bedrock weathering (BW) controlled that of Zn. In the A horizon, the distribution of Cd and Pb depended on the vegetation regulation, whereas that of Zn was mainly related to BW. Human activity, including ores mining and fossil fuels combustion, increased the trace metal deposition in the surface soils. The anthropogenic percentage of Cd, Pb, and Zn quantified 92.4, 67.8, and 42.9% in the O horizon, and 74.5, 33.9, and 24.9% in the A horizon, respectively. The anthropogenic metals deposited at the high altitudes of Mt. Luoji reflected the impact of long-range atmospheric transport on this remote alpine ecosystem from southern and southwestern regions.
authors.affiliation: The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China.|University of the Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.affiliation: The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China.
authors.forename: Haijian
authors.initials: H
authors.lastname: Bing
authors.affiliation: The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China. yhwu@imde.ac.cn.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Wu
authors.affiliation: The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: The Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China.|University of the Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Zhongxiang
authors.initials: Z
authors.lastname: Xiang
mesh_terms: D000531:Altitude; D002681:China; D017753:Ecosystem; D004784:Environmental Monitoring; D006801:Humans; D019216:Metals, Heavy / Q000032:analysis*; D008956:Models, Chemical; D010944:Plants / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D013696:Temperature
chemical_list: D019216:Metals, Heavy; D012989:Soil Pollutants
keywords: Alpine soils; Atmospheric deposition; Luoji Mountain; Pb isotopic composition; Trace metals