海岸带不同林龄木麻黄对重金属的吸收与富集作用

Absorption and enrichment of heavy metals by Casuarina equisetifolia of different stand ages in a coastal zone

为研究不同林龄木麻黄对重金属的吸收与富集作用,用ICP-MS测定了福建东山县国有防护林场10、16、20、30年生木麻黄小枝、细根、凋落物及林地土壤中的5种重金属(Cr、Cu、Zn、Cd和Pb)含量。结果表明,木麻黄对不同重金属的吸收能力不同,从高到低为Zn>Cr>Pb>Cu>Cd;木麻黄细根中Cr和Cu、Pb,Fe和Cu,Zn和Cd具有明显的协同作用;各林龄木麻黄对重金属均具有一定的耐性,对Cu、Zn、Cd、Pb有很好的富集作用;20年生木麻黄的重金属年积累量最高;说明木麻黄对重金属的净化作用具有极大的潜力,20年生木麻黄作用最为明显。

To assess the absorption and enrichment of heavy metals by Casuarina equisetifolia, the concentrations of heavy metals including Cr, Cu, Zn, Cd and Pb in branchlet, fine root, litter and soil of C. equisetifolia forests at four ages （10, 16, 20, 30） were determined. The results showed that the enrichment degree of the heavy metals in C. equisetifolia ranked as Zn〉Cr〉 Pb〉Cu〉Cd. Correlation analysis showed that Cr and Cu, Pb, Fe and Cu, Zn and Cd had significant synergies in the fine roots of C. equisetifolia. C. equisetifolia had a higher capability of ab- sorbing and accumulating heavy metals. Annual accumulation of heavy metals was highest in 20 years old C. equisetifolia. Our results indicate that C. equisetifolia has a great potential for reducing the pollution of heavy metals, especially for the 20 years old forest.