Understanding atmospheric mercury(Hg)accumulation in remote montane forests is crit-ical to assess the Hg ecological risk to wildlife and human health.To quantify impacts of vegetation,climatic and topographic factors on Hg accumulation in montane forests,we as-sessed the Hg distribution and stoichiometric relations among Hg,carbon(C),and nitrogen(N)in four forest types along the elevation of Mt.Gongga.Our results show that Hg concen-tration in plant tissues follows the descending order of litter＞leaf,bark＞root＞branch＞bole wood,indicating the importance of atmospheric Hg uptake by foliage for Hg accu-mulation in plants.The foliar Hg/C(from 237.0±171.4 to 56.8±27.7 μg/kg)and Hg/N(from 7.5±3.9 to 2.5±1.2 mg/kg)both decrease along the elevation.These elevation gradients are caused by the heterogeneity of vegetation uptake of atmospheric Hg and the variation of atmospheric Hg° concentrations at different altitudes.Organic soil Hg accumulation is controlled by forest types,topographic and climatic factors,with the highest concentration in the mixed forest(244.9±55.7 μg/kg)and the lowest value in the alpine forest(151.9±44.5 μg/kg).Further analysis suggests that soil Hg is positively correlated to C(r2=0.66)and N(r2=0.57),and Hg/C and Hg/N both increase with the soil depth.These stoichiomet-ric relations highlight the combined effects from environmental and climatic factors which mediating legacy Hg accumulation and selective Hg absorption during processes of organic soil mineralization.

Shufang Zeng;Xun Wang;Wei Yuan;Ji Luo;Dingyong Wang

College of Resources and Environment,Southwest University,Chongqing 400715,China;State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;Key Laboratory of Mountain Surface Processes and Ecological Regulation,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences&Ministry of Water Conservancy,Chengdu 610041,China

环境科学学报（英文版）

[1]Shufang Zeng;Xun Wang;Wei Yuan;Ji Luo;Dingyong Wang-.Mercury accumulation and dynamics in montane forests along an elevation gradient in Southwest China)[J].环境科学学报（英文版）,2022(09):1-10

stoichiomet

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