个旧锡矿山废弃地不同土地利用方式土壤重金属的影响

为研究锡矿山不同土地利用方式的重金属污染变化状况，通过对个旧锡矿山废弃地的7个不同土地利用方式采样点土壤物理性状、土壤养分状况及重金属进行测定分析。结果表明，土壤物理性状与耕作、施肥和植被恢复具有一定的关系，通过采取合理的植被恢复措施，可以逐步改善土壤的物理性状；在土壤养分方面，小黑山农地土壤养分较高，和土壤施肥关系较大，杜仲林地的各指标相对其他林地和尾矿库明显在增加，说明随着植被恢复时间的增加，土壤肥力逐渐得到改善；从重金属含量来看，牛坝荒农地和尾矿库的Cu、Zn、Pb、As、Cd各项指标值均居于较高水平，牛屎坡1#、牛屎坡林地2#、白虎山杜仲林地的Cu、Pb、As、Cd指标值较牛坝荒尾矿库农地和尾矿库以及小黑山农地低，说明植物恢复措施对降低重金属的含量具有一定的作用；锡矿山废弃地土壤肥效和土壤重金属污染程度存在一定关系，有机质与Cu、As呈极显著负相关，水解N与Cu、As呈极显著负相关，与Cd、Pb呈显著相关，全N与Cu具显著相关性，与As具有极显著相关性。

Contents of Heavy Metals in the Soils of Abandoned Land under Different Land Use Patterns in the Gejiu Tin Mine

In order to study the changes of heavy metal pollution in the soils under different land use types in tin mines,soil physical properties,nutrients and the contents of heavy metals of the soil samples collected from 7 locations where different land use patterns were adopted around Gejiu tin mine.The results showed that physical properties of the soils were related in some extents with the ways of cultivation,fertilization,and vegetarian restoration,indicating that soil physical properties could be improved by rational measures of vegetation restoration.In term of soil nutrients,it was observed that the soil of Xiaoheishan farmland were rich in nutrients that was resulted from high level of fertilization.Compared with other forest lands and tailings,each index in the soil of Eucommia ulmoides forest was high,demonstrating that soil fertility was improved with the increase of vegetation restoration.Judging from the heavy metal content,abundant farmlands and tailings in Niubahuang presented high levels of Cu,Zn,Pb,As,and Cd.However,lower levels of Cu,Pb,As,and Cd were found in the soils from No.1 and No.3 sampling plots in Niushipo,and E.ulmoides forest in Baihushan,demonstrating that measures for vegetation restoration played certain roles in reducing the levels of heavy metals.It was also found that certain correlations were existed between soil fertility and heavy metal pollution degrees:levels of soil organic mater were most significantly correlated to the contents of Cu and As;hydrolysable nitrogen was most significantly and negatively correlated to Cu and As,significantly correlated to Cd and Pb;total N was significantly correlated to Cu,most significantly correlated to As.