自然植物群落对铜尾矿废弃地土壤酶活性的影响

在铜陵铜矿区堆存着大量的不同时期弃置的尾矿废弃物,形成大面积铜尾矿废弃地。为了解自然植物群落对铜尾矿废弃地酶活性的影响,对铜陵铜矿区6处不同时期弃置的铜尾矿废弃地进行了调查。结果表明,自然定居在尾矿废弃地上的植物群落类型能够显著影响表层尾矿中(0~5 cm)的脲酶、芳基硫酸酯酶、碱性磷酸酶和脱氢酶的活性。位于木贼-中华结缕草群落和白茅群落下尾矿中的几种土壤酶的活性高于位于狗牙根群落和中华结缕草群落下的尾矿中酶的活性。在所测定的4种土壤酶中,碱性磷酸酶和脱氢酶的活性高于脲酶和芳基硫酸酯酶的活性。相关分析表明,4种土壤酶的活性与表层尾矿中的腐殖质、总氮、有效磷、速效钾含量以及电导率表现出显著正相关,而芳基硫酸酯酶和脱氢酶与pH之间存在着显著负相关。强烈氧化的表层尾矿不仅具有极端贫瘠的养分条件,同时也具有极低的土壤酶活性。

EFFECT OF NATURAL PLANT COMMUNITIES ON SOIL ENZYME ACTIVITIES IN DESERTED COPPER MINE TAILINGS DUMPS

A large number of deserted copper mine tailings dumps of different age exist in Tongling,East China,covering a large area of land.In order to understand effect of natural plant communities on enzyme activities in the soil,six dumps different in age were investigated.The results show that the plant communities naturally colonizing on the wastelands markedly increased enzyme activities(urase,arylsulfatase,alkaline phosphatase and dehydrogenase)in the upper layer of the tailings(0~5 cm).But the effect varied with the type of the plant communities.Enzyme activities in tailings under the Hippochaete ramosissmium-Zoysia sinica community and Impreta cylindraca community were higher than under the Cynodon dactylon community and Zoysia sinica community.Of the 4 soil enzymes studied,alkaline phosphatase and dehydrogenase were higher than urase and arylsulfatase in activity.Data analysis indicates that there was a significantly positive correlation between enzyme activities and chemical propert ies(including humus,total nitrogen,available phosphorus,available potassium and electrical conductivity), but a significantly negative correlation between pH values of the tailings and act ivities of arylsulfatase and dehydrogenase.The surface layer of tailings heavily oxidized exhibited extreme infertility and extremely low activities of soil enzymes.