At a large scale (China),climatic factors such as monsoon and precipitation probably provide significant contributions to spatial distribution of mercury (Hg) and selenium (Se) in soil considering their volatile properties.However,it is still unclear which factors influence Hg and Se accumulations in surface soil and what their contribution rates are.This study mainly analyzes the contributions of dry and wet depositions and volatilization to accumulations of Hg and Se in surface soil,and argues that the accumulation of Hg and Se in surface soil is a dynamic process.At a national scale,the contribution rates of wet deposition to surface soil Se and Hg are 91.5% and 49.4%,respectively.The contribution of normalized difference vegetation index (NDVI) to soil Hg is 23.4%.Since mercury and selenium exist in different ways in the atmosphere,Hg is dominated by insoluble Hg⁰,while Se is dominated by soluble methylated Se.The contributions of dry and wet depositions to Hg and Se are significantly different.This study systematically presents the climatic factors affecting the distributions of Hg and Se in surface soil,and has important guiding significance for comprehensive understanding of the biogeochemical cycles of Hg and Se.

surface soil  /  soil mercury  /  soil selenium