N、P添加对亚热带森林土壤重金属活性的影响

Analysis of the Activities of Heavy Metals in Forest Soil Under N and P Addition

文章为阐明杉木林土壤重金属含量及其与环境因子的关系,对杉木林进行氮磷添加,设置4个不同处理(CK、N_(1)、N_(2)和P),测定了土壤Cr、Cu、Fe、Mn和Zn含量以及土壤基本理化性质。结果表明:N、P添加后,在6种处理中,杉木林土壤重金属的含量Fe>Mn>Cr>Cu>Zn,Cr和Cu的相对增加量为正值,而Mn和Zn相对增加量基本为负值。Pearson相关分析表明pH与Fe表现出显著正相关性,并且重金属元素之间也有一定的相关性。冗余分析表明全磷和pH值对土壤金属Cr和Cu活性的影响较大,土壤全碳、全氮和含水量对金属Mn、Zn和Fe活性较大。路径分析表明各影响因素之间的直接和间接效应最终通过级联效应影响重金属活性。

4 different treatments(CK,N_(1),N_(2) and P)were conducted to study the contents of heavy metals in the soil of Cunninghamia lanceolata and the relationship among its environmental factors.Concentrations of Cr,Cu and Fe,Mn and Zn in the soil were detected and soil physical and chemical properties were tested.The results showed that the order of concentrations of heavy metals in the soil were Fe>Mn>Cr>Cu>Zn,the positive relative increase of Cr and Cu,but the negative relative increase of Mn and Zn were in the 6 thtreatment.Pearson correlation analysis showed that pH and Fe are a significant positive correlation,and there was a certain correlation among heavy metals.Redundancy analysis(RDA)showed that soil total phosphorus and p H are great influence on the activities of Cr and Cu,while total carbon,total nitrogen and water content are great influence on the activities of Mn,Zn and Fe.The structural equation model showed that the direct and indirect effects among the influencing factors ultimately affected the activity of heavy metals by cascade effects.