南洞庭湖湿地优势植物重金属含量及富集特征

通过野外调查采样,分析了南洞庭湖湿地8个采样点土壤和优势植物中重金属含量,以及南洞庭湖湿地9种优势植物对Cd、Cu和Sb的吸收及富集特性.结果表明,南洞庭湖湿地土壤中3种重金属元素的平均含量均超出湖南省土壤背景值和全国土壤背景值,土壤受Cd污染最严重.9种优势植物体内Cd、As和Sb的含量较高,具有修复洞庭湖湿地土壤Cd、As和Sb污染的潜力.其中蒌蒿（Artemisia selengensis）对Cd和Sb表现出显著的富集转移特征,可作为洞庭湖湿地土壤污染修复的备选材料.八棱麻（Boehmeria siamensis）对Sb的富集系数和转运系数均大于1,对重金属有较强耐受性,作为重金属污染的修复植物具有较好的应用前景.

Accumulation and Distribution of Heavy Metals in Dominant Plant Species in South Dongting Lake Wetland

A study was conducted to investigate heavy metal contents in dominant plant species and their associated soils in the south Dongting Lake wetland area. Contents of such heavy metals as Cd, Cu and Sb were determined in 9 dominant plant species in order to assess their potentials in phytoremediation of heavy metal polluted areas. The results revealed that all the average contents of the three heavy metals in soils of south Dongting Lake wetland area had exceeded the background value of heavy metals in Hunan and in China The soil of south Dongting Lake area was seriously polluted by Cd, Cu and Sb. The Cd, As and Sb concentration in the 9 dominant plant species exceeded the normal ranges, indicating their potentials in in-situ remediation of the heavy-metal contaminated Dongting Lake wetland soils. Among the studied plant species, both the bio-accumulating coefficient and the biological transfer coefficient of Artemisia selengensis were greater than l, and this species can be designated as an ideal plant for the bioremediation of heavy metal polluted soil in Dongting Lake wetland area. It can be used as pioneer plants for revegetation of contaminated soil in mining area. In addition, Boehrneria siamensis could concentrate different heavy metals and both bio-accumulating coefficient and biological transfer coefficient of its were over 1 for Sb, which had a better potential and practical use in phytoremediation.