广东大宝山矿区植物对重金属的富集特征

Heavy Metal Accumulation Characteristics of Plants in Dabaoshan Mine in Guangdong Province

对大宝山矿区自然定居和人工种植的13种优势植物根际土壤污染状况及其对重金属的富集特征进行研究。结果表明,大宝山矿区土壤受重金属Cd、Pb、Zn、Cu污染,其中以Cd、Cu的污染最为严重。在调查的13种优势植物中,铺地黍地上部分的Pb含量达到1 214.00mg/kg,泡桐叶中Cu含量达到1 024.80mg/kg,超过了Pb和Cu超富集植物含量的临界值(1 000mg/kg);其运转系数分别为1.77,13.74,都大于1.0,符合超富集植物的标准,表明铺地黍可能是Pb的超富集植物,泡桐可能是Cu的超富集植物。除铺地黍、泡桐外,其他11种优势植物的重金属吸收能力没有达到超富集植物的标准,但它们能在此区域定居,表现出对重金属有较强的耐性,其中象草、纤毛鸭嘴草、芒萁、五节芒、马尾松对重金属复合污染胁迫的耐性较强,可作为大宝山矿植被重建的先锋物种。

The author researched about the pollution condition of root soil and heavy metal accumulation characteris- tics of 13 kinds of dominant plants naturally settled or human cultivated in the Dabaoshan mine. The results showed that soil in Dabaoshan mine was polluted by heavy metal CA, Pb, Zn and Cu, especially by Cd and Cu. In this re- search, the Pb content of aerial parts of Panicum repens reached 1 214.00 mg/kg; the Cu content of Paulow- nia fortunei leaves reached 1 024.80 mg/kg, both of which were more than 1 000 mg/kg. The threshold of Pb and Cu hyper-aeeumulation plants~ the biological transfer coefficients were 1.77 and 13.74, greater than 1.0, which were also satisfied with the standard of hyper-accumulation plants, indicating that Panicum re- pens might be a kind of Pb hyper-accumulation plant, and Paulownia fortunei might be a kind of Cu hyper- accumulation plant. Though the other 11 kinds of dominant plants did not fit the standard of hyper-aeeumu- lation plants of absorbing heavy metals, the fact that they could settle in this region showed they also had strong heavy metals tolerance. Pennisetum purpureum , lschaemum ciliare , Dicranopteris dichotoma , Miscanthus floridulus and Pinus massoniana were significantly tolerant to the heavy metal pollution stress, which could be served as pioneer soeeies in the procedure of vegetation reeonstruction of Dabaoshan mine.