Distribution of heavy metals forms and its affecting factors in rhizosphere soils of Hippochaete ramosissimum in large-scale copper tailings yard
大型铜尾矿库区节节草(Hippochaete ramosissimum)根际土壤重金属形态分布与影响因素研究

Based on the field investigation and laboratory analysis, it was studied that the forms, contents and distribution of Cu,Pb,Cd and Zn of rhizosphere and non-rhizosphere soils of H. ramosissimum in Tongguanshan copper tailings yard, Shizishan copper tailings yard and the farmland beside Shizishan copper tailings yard of Tonglin City, Anhui Province. The results showed that distribution of different forms of the heavy metals of rhizosphere and non-rhizosphere soils of H. ramosissimwn had a similar trend. It indicated that the contents of residual had occupied the great part of heavy metals, and the exchangeable had a few. Compared with non-rhizosphere soils, the contents of organic combined and exchangeable in rhizosphere soils of H. ramosissimum had increased, among them, the organic combined of Cu increased 53.25%, Pb and Cd increased more than 17%, and Zn 5.67% in average. At the same time, the contents of carbonate combined and Fe-Mn oxides combined decreased. The major factors that effected on the chemical forms of heavy metals in rhizosphere soils of H. ramosissimum were pH, organic matter and the growth of plant etc.