植被恢复模式对土壤重金属质量分数和土壤酶活性的影响——以山东省淄博市四宝山破坏山体为例

Effects of different modes of vegetation restoration on soil heavy metal contents and soil enzyme activities:A case study in damaged mountain body in Sibaoshan County,Zibo City,Shandong Province

矿产资源开采造成了严重的重金属污染,为选择合理植被恢复模式以修复土壤重金属污染,以淄博市四宝山破坏山体不同植被恢复模式为对象,测定土壤有机质、全氮、碱解氮、有效磷、速效钾质量分数,pH值等主要化学性质,土壤多酚氧化酶、过氧化氢酶、过氧化物酶、脲酶活性和Cu、Zn、Cd等7种重金属质量分数,分析不同植被恢复模式对土壤重金属质量分数及土壤酶活性的影响。结果表明:1)实验区土壤中重金属Zn轻度污染,Cu和Cd重度污染,其他重金属均不构成污染;2)各人工植被恢复模式土壤重金属质量分数均低于灌草丛的,其中黑松林对土壤Cu、Cd的修复效果最好,侧柏林对土壤Zn的修复效果最好;3)土壤重金属全量在垂直分布上规律复杂,有效量均表现为下层高于上层,土壤有效Cu、有效Zn、有效Cd下层比上层依次高9.24%～18.94%、0.97%～20.09%和5.48%～35.51%;4)在影响土壤酶活性的各种因素中,破坏山体土壤重金属有效量与土壤化学性质的影响最为明显,处于同等重要的地位。本研究发现,Cu、Zn、Cd均对4种土壤酶活性表现出了抑制作用,建议用土壤多酚氧化酶、过氧化氢酶、脲酶活性作为破坏山体土壤重金属Cu污染的评价指标。

Exploitation of mineral resources has caused serious heavy metal pollution,in order to choose a reasonable vegetation restoration mode for the soil heavy metal pollution,were taken different vegetation restoration modes of the damaged mountain body in Sibaoshan County,Zibo City as object of the study,the activity of soil enzymes（polyphenol oxidase,catalase,peroxidase and urease）,the content of heavy metals（Cu,Zn,Cd,Mn,Pb,Cr and Ni） together with its chemical properties（organic materials,the total nitrogen content,alkalinized nitrogen,available phosphorus and potassium and the pH value） were measured,and the content of heavy metals and the activity of enzymes in the soil of different vegetation restoration modes were analyzed.The results showed that soil was heavily polluted by Cu and Cd,lightly polluted by Zn,and not polluted by Mn,Pb,Cr and Ni.The contents of soil heavy metals for all vegetation restoration modes were lower than that of brushwood.Moreover,the remediation effect of Pinus thunbergii forest was best for soil polluted by Cu and Cd,whereas Platycladus orientalis forest performed best in remediation of soil polluted by Zn.Vertical distribution law of soil heavy metals was complex,an effective amount of of available Cu,Zn and Cd in lower layer is higher than in the upper layer by 24.00%-18.94%,0.97%-20.09% and 5.48%-35.51%,respectively.In a variety of factors affecting soil enzyme activities,effect of content of heavy metals and soil chemical properties of soils was most obvious,and both were of equal importance,this study found that the soil enzyme activity was largely inhibited by Cu,Zn and of Cd,Hence,polyphenol oxidase,catalase and urease could be used as indicators for soil Cu pollution in damaged mountain body.