商洛金凤山不同林地土壤重金属含量研究

A Study on Heavy Metal Content of the Different Forestland Soil in Jinfeng Mountain of Shangluo

重金属是威胁林地生态健康的主要污染物之一,为了了解商洛金凤山土壤的重金属含量特征和污染状况,在金凤山核桃、刺槐、构树和橡树4种人工林地采集了25份土壤样品,测定了土壤中重金属元素Cu、Pb、Cr、Ni、Zn的含量,并采用地积累指数、内梅罗综合污染指数和潜在生态风险指数评价了4种人工林土壤的重金属污染情况。结果表明,金凤山4种人工林地土壤重金属元素Cu、Pb、Cr、Ni、Zn的平均含量分别为9.53,13.7,16.4,11.56,57.3 mg·kg-1,大小依次为Zn>Cr>Pb>Ni>Cu,均未超过陕西省土壤重金属含量背景值。地积累指数表明5种重金属均无污染风险,内梅罗综合污染指数表明土壤整体质量已处于轻度污染状态,刺槐林地土壤重金属潜在生态风险程度属于中等,其他3种林地土壤潜在生态风险程度为低等。

Heavy metals are one of the main pollutants that threaten the forest ecological health.A total of 25 soil samples were collected from four artificial forest including Juglandis,Robinia pseudoacacia,Broussonetia papyrifera and Quercus palustris Münchh.The contents of heavy metal elements Cu,Pb,Cr,Ni and Zn in the soil were determined.The heavy metals pollution were evaluated with the method of accumulated pollution index,Nemero comprehensive pollution index and potential ecological hazard index.The results showed that the average contents of the elements Cu,Pb,Cr,Ni,Zn were 9.53,13.7,16.4,11.56,57.3 mg·kg-1,respectively,which were less than the background value of soil heavy metals elements in Shaanxi Province.The order of the average content of the five heavy metals in the soil of the Jinfeng mountain was Zn>Cr>Pb>Ni>Cu.The field accumulation index indicated that there were no pollution risks for the five heavy metals.The Nemero comprehensive pollution index showed that the overall quality of the soil was already in a state of light pollution.The degree of the heavy metals′potential ecological risk in Robinia pseudoacacia forest soil was medium,while the degree of potential ecological risk of other three forest lands were low.