Impacts of Spectral Characteristics of Dissolved Organic Matter on Methyl Mercury Contents in Permafrost Wetlands, Northeast China

Dissolved organic matter (DOM) plays an important role in promoting or suppressing methylmercury (MeHg) production in wetlands. However, in the context of climate warming, the regulatory mechanism of DOM composition and molecular structure changes in permafrost wetland soil on mercury methylation remains unclear. In this study, we analyzed the distribution characteristics of mercury and methylmercury in permafrost wetland soils in the Greater Khingan Mountains (GKM), and elucidated the driving mechanism of mercury methylation by basic physical and chemical properties and DOM spectral characteristics of soils. The results showed that the mean value of total mercury in the permafrost wetlands of the GKM was 111 ng·g-1, the mean value of methylmercury was 5.69 ng·g-1, and the mean percentage of methylmercury was 6.16