南丹长坡尾矿坝五种植物富集重金属的生态调查

为寻找适合矿业尾矿废弃地生态恢复和植物修复的植物，有效的进行矿业尾矿废弃地植被生态恢复，本文调查分析广西南丹长坡矿堆存50年之久的尾矿坝上的灯心草、节节草、类芦、莎草和醉鱼草的覆盖度、生物量以及植物体内的重金属含量。结果表明：这5种植物覆盖度超过40％，高度超过40cm，为该尾矿坝的优势植物，且具有较高生物量，特别是类芦、灯心草和莎草，生物量均超过20g／株（干重），说明这些植物适合尾矿坝环境。对重金属有很高耐性。5种植物中，类芦地上部分Zn含量最高为286．45mg／kg，醉鱼草地上部分Ph和Cd含量最高，分别为148．46mg／kg和5．54mg／kg，都未达到超富集植物标准，考虑到高生物量和重金属的耐性，这5种植物在矿废弃地生态恢复和植物修复中都有一定应用价值。此外，5种植物对重金属的转运能力有较大差异，其中醉鱼草对3种重金属的转运系数均超过1，其转运机理值得进一步探讨。

Ecological Investigation of Heavy Metal Accumulation in Five Plants at Changpo Mine Tailing of Nandan

To find suitable plants for ecological restoration of mine tailing and phytoremediation, a field investigation were conducted on Medulla Junci, Hippochaete ramosissimum, Neyraudia reynaudiana, Cyperus michelianus and Buddleia lindleyana in the Chang-po mine tailing which had high concentration of Zn, Pb and Cd and has stayed for over 50 years in Nandan in Guangxi. The results showed that the five plants are the dominant plants on the mine tailing as their ground coverage and heights were all over 40% and 40 cm, respectively. The five plants owned high biomass too, especially N. reynaudiana, C. michelianus and M. Junci, whose biomass are more than 20 g per plant. That shows, these plants adapt themselves to the environment with high concentration of heavy metals and own high tolerance to them. According to the metal accmulation, the five plants are not hyperaccumulators, as the highest Zn （286.45 mg/kg） in content was found in N. reynaudiana and the highest Pb （148.46 mg/kg） and Cd （5.54 mg/kg） are both found in B. lindleyana. However, when their high biomasses and metal tolerance are considered, the five plants have rather high potential in ecological restoration of mine tailing and phytoremediation. Moreover, the abilities of metal transportation are different among the five plants. The transportation factors （TFs） of Zn, Pb and Cd in B. lindleyana are all over 1. Thus, the mechanism of metal transportation in B. lindleyana needs more investigation.