Variance of mercury in typical plant litters in Sanjiang Plain Wetland
三江平原典型湿地植物枯落物中汞的变异特征

In the field experiment, temporal variance of mercury of two typical wetlands vegetal litters was researched and the affecting factors were discussed. Mercury concentration of most layers in two litters increased after 30 days, then decreased, and increased at last in the decomposition during a growth season. The variance of mercury concentration was related to the degree of the litters decomposition. At the initial 90 days, the mass of the litter lost quickly, and mercury concentration decreased, so much mercury in litters was lost. The loss of mercury was little at last stage because of the increasing ability of adsorption to mercury. In the depth of 20cm and 30cm, loss of mercury correlated significantly with the depth of inundated water and soil temperature (P<0.05). The difference of microenvironment, especially the change of inundation, affected on the mercury loss of Carex lasiocarpa litters more than Calamagrostis angustifolia litters in different depth.