辽河口不同类型湿地土壤汞、甲基汞含量及其影响因素

Mercury and methylmercury concentrations and their influencing factors in soils of different types of wetlands of Liaohe Estuary

通过对辽河口三道沟、笔架岭两地不同类型湿地土壤中总汞、甲基汞以及影响因素的研究,从植物自然演替的角度,分析了辽河口不同类型湿地总汞、甲基汞的分布及转化因素。结果表明:不同类型湿地土壤汞含量为0.036~0.069 mg·kg^(-1),土壤甲基汞含量为0.77~2.56μg·kg^(-1);三道沟湿地土壤汞、甲基汞含量明显低于笔架岭湿地;从光滩到芦苇湿地,表层土壤汞、甲基汞含量逐渐降低;从笔架岭湿地剖面分析来看,从表层到深层,芦苇湿地、碱蓬湿地土壤汞、甲基汞含量逐渐降低,光滩剖面土壤汞含量先增加后降低再增加,光滩土壤甲基汞含量总体上呈降低趋势;从土壤总汞、甲基汞与其他影响因素的关系看,土壤汞与甲基汞具有显著相关关系,土壤汞与钾、易溶性盐具有正相关关系。

The distribution and conversion factors of soil total mercury and methylmercury in different types of wetlands in Liaohe Estuary （two sites： Sandaogou and Bijialing） were analyzed along plant natural succession to study the levels of total mercury and methylmercury and their influencing factors. The results showed that the concentration of total mercury ranged from 0.036 to 0.069 mg·kg-1 and the concentration of methylmercury ranged from 0.77 to 2.56 μg·kg-1 in different types of wetlands soil in Liaohe Estuary. The concentrations of total mercury and methylmercury were significantly lower in Sandaogou wetlands than in Bijialing wetlands. The concentrations of total mercury and methylmercury in surface soil gradually decreased from mudflats to Phragmites australis wetlands. The concentrations of total mercury and methylmercury gradually decreased from the surface soil layer to the deep soil layer in Ph. australis wetlands and Suaeda salsa wetlands. The concentration of total mercury showed a trend of increasedecreaseincrease along the soil profile in mudflats of Bijialing, while the concentration of methylmercury was decreasing overall. The concentration of total mercury had a significant correlation with methylmercury concentration and a positive correlation with concentrations of potassium and soluble salts.