三江平原湿地汞的地球化学特征

三江平原典型湿地土壤、植物、地表水中的总汞含量较高，表层土壤汞含量平均为88．4ng/g，高于本地区耕地土壤，并具有从上到下逐渐减少的趋势；在草根层和泥炭层土壤中，总汞含量为毛果苔草沼泽＞乌拉苔草沼泽＞小叶樟沼泽，与积水条件一致；湿地开垦以后总汞含量明显减少，耕地土壤在开垦初期降低速率很快。湿地植物汞含量较高，湿地水中的总汞含量春季为58．4－131．6ng/L。初步认为三江平原湿地汞的主要来源为大气沉降，湿地是河流和水库中汞的重要来源，人类活动增强了湿地中汞的迁移。

The geochemistry characteristic of mercury in Sanjiang Plain Marsh

Total mercury content of soil, plant and water in Sanjing Plain Marsh were high. Total mercury content in the surface of soil was 88 4?ng/g, higher than the cultivated land. Total mercury in soil decreased with the depth of soil. In the sod and peat layer, Total mercury of Carex lasiocarpa marsh> Carex meyeriana marsh> Calamagrostis angustifolia marsh, it was consistent with the seeper. Hg content decreased significantly after the reclamation,especially in the earlier years. The content of mercury in wetland plant was high. Hg content of water ranged from 58 4 to 13 16?ng/L in spring. The main source of mercury in Sanjiang Plain was the atmosphere. The wetland was an important source of mercury in river and lakes. The human activities enhanced the transportation of mercury in wetlands.