三江平原典型湿地植物中汞的分布与库存量

分析了三江平原典型植物中的总Hg浓度．结果表明，各种植物中总Hg浓度差别较大，苔藓>藻类>苔草>禾草>灌木；干湿环境是影响总Hg浓度的重要因素；湿地植物总Hg浓度高于水稻和玉米等农作物．较高的土壤总Hg浓度是近地面大气中Hg的重要来源，间接地影响到植物中Hg的浓度．植物各构件中总Hg浓度具有立枯>根>叶>茎的特点．在植物整个生长季总Hg浓度先增加后减少．估算了三江平原湿地植物Hg的库存量．小叶章湿地植物地上部分库存量为24．9μg·m^-2；毛果苔草湿地植物地上部分库存量为35．8μg·m^-2，高于加拿大实验湖泊湿地．

Distribution and stock of mercury in typical wetland plant in the Sanjiang Plain

Total mercury concentration of typical wetland plant was analyzed. There were great difference in mercury content among different plants, and the order was moss > alga > carex > herb > shrub. There was a trend of increasing total Hg concentrations from vascular plants to bryophytes, and from dry to wet site. The wetland soil was the source of mercury in the air close to the ground, so it influenced the content of mercury in the plant. In different components of plants, mercury contents were in the order of dead stand > root > leaf > stem. Mercury concentration increased in initial stage and decreased in the end of the growing season. According to the mercury content and biomass, the mercury stock of plant were calculated, and it was 24.9 micrograms.m-2 in the above ground of plant in Calamagrostis angustifolia wetland and 35.8 micrograms.m-2 in Carex lasiocarpa wetland.