DISTRIBUTION OF MERCURY IN TYPICAL WETLAND PLANTS IN THE SANJIANG PLAIN

Total mercury concentration of typical wetland plants was analyzed in this paper. There were great differences of total mercury concentration among different plants: moss>hydrophyte>sedge>herbage>shrub. Total mercury concentrations show an increasing trend from vascular plants to bryophytes, and from dry to wet lands. The mercury concentration of wetland plants was higher than that of crops. The wetland soil was the source of mercury in the air close to the ground, so it affected the concentration of mercury in the plant. In different parts of a plant, mercury concentration was in the order of: dead stand>root>leaf>stem. Mercury concentration increased at the initial stage and decreased in the end of the growing season. According to the mercury content and biomass, mercury stock of plants was 39.41 mu g/m(2) above ground in Calamagrostis angustifolia wetland and 35.8 mu g/m(2) in Carex lasiocarpa wetland.