铜绿山矿冶废弃地优势植物重金属的积累与迁移

通过野外调查和取样分析，研究了大冶铜绿山矿冶废弃地鸭跖草等5种优势植物对重金属的吸收累积与迁移特性,以期为矿区退化生态系统的植被恢复、重金属污染土壤的治理等提供依据。结果表明，鸭跖草等5种植物对重金属Cu、Pb、Zn、Cd、Cr都有程度不等的高量积累，尤其是铜元素，其最高积累量出现在海洲香薷根部，达到844.65 mg/kg，是一般植物Cu含量（5~25 mg/kg）的33.8~1689倍；而在同样条件下，As在5种植物体内的含量为018~098 mg/kg，远远低于As在一般植物中的含量（＜10 mg/kg），这说明这些植物对As可能具有某种规避机制。从植物对重金属的吸收、富集和转运能力综合考虑，鸭跖草等5种植物都不太可能是重金属Cu等6种重金属的超累积植物。但是，它们对重金属所表现出的耐性无疑对矿冶废弃地的植被恢复过程有重要意义。

ACCUMULATION AND DISTRIBUTION OF HEAVY METALS IN DOMINANT PLANTS GROWING ON TONGLUSHAN MINERAL AREAS IN HUBEI PROVINCE, CHINA

Tonglushan Mine, located in the Southeastern part of Hubei Province,China, is one of the six copper mines in China and has more than 3 000 years history in mining.A lot of higher plants are growing on an ancient copper spoil heap (3 000 years old) on Tonglushan.Some of the plants are superior in number.Significant correlation may exist between the amount of heavy metals in these dominant plants and that in related soil. In order to provide scientific basis for the vegetation restoration of deteriorative eco system in mining districts and phytoremediation of soil polluted by heavy metals,the accumulation and distribution of heavy metals in some dominant plants growing on Tonglushan mineral area were investigated via field survey and sample analysis.Five dominant species including 〖WTBX〗Commelina communis,Elsholtzia haichowensis,Silene fortunei,Polygonum perfoliatum〖WTBZ〗 and 〖WTBX〗Kummerowia striata〖WTBZ〗 were found to have high concentration of total Cu,Pb,Zn,Cd,Cr.In particular,Cu had a high concentration in the root of 〖WTBX〗Elsholtzia haichowensis〖WTBZ〗,being at 84465 mg/kg,which is 338~1689 times higher than the general content in plants (5~25 mg/kg).But the concentration of total As in these species was 018~098 mg/kg,lower than the average in general plants.It can be deduced that these species have a kind of mechanism to evade assimilating As from soil.It is indicated that 〖WTBX〗C.commelis,E.haichowensis,S.fortunei,P.perfoliatum〖WTBZ〗 and 〖WTBX〗K.striata〖WTBZ〗 were not the hyperaccumulator for heavy metals Cu,Pb,Zn,Cd,Cr and As,but they were high heavy metals tolerant species.Moreover, these species will play an important role in vegetation restoration of abandoned mine sites.〖