不同林龄桉树林地表节肢动物对钨尾矿重金属污染的响应

Response of Ground Surface Arthropods in Eucalyptus Forests of Different Ages to Heavy Metal Pollution of Tungsten Tailings

为研究钨尾矿重金属污染对不同林龄桉树林地表节肢动物多样性的影响,选择尾矿区及外围3个不同年龄的桉树林作为研究样地,以远离尾矿的桉树林为对照,研究其地表节肢动物群落的群落多样性、相似性及其与土壤环境因子的相关性.结果显示:1年桉林、7年桉林和26年桉林共捕获地表节肢动物14目39科共907只,对照桉林共捕获地表节肢动物14目58科共1039只.桉林地表节肢动物的个体数和类群数以1年桉林、7年桉林、26年桉林和对照桉林的顺序呈递增趋势.4个桉林样地共有的优势类群为蜘蛛目和膜翅目.对照桉林地表节肢动物的类群数、个体数、丰富度指数、多样性指数显著高于其他桉林样地,26年桉林样地次之,并且二者均显著高于7年桉林和1年桉林样地,1年桉林样地最低.nMDS排序和SIMPER相似性分析表明,1年和7年桉林与矿区外围26年桉林和对照桉林样地地表节肢动物群落结构存在明显的差异.Pearson相关性分析表明,桉林地表节肢动物的物种数、个体数、丰富度指数、多样性指数与有机质含量、全氮、含水率、pH值、速效磷等土壤肥力因子呈极显著正相关,与重金属Zn、Cu、As、Cd、Pb呈极显著负相关.钨尾矿重金属污染导致生境的土壤理化营养因子指标土壤基质与地表节肢动物群落多样性下降,但在生态恢复中,地表节肢动物个体数、类群数及多样性指数随着桉树种植年限增加而呈现升高的趋势.

In order to study the effects of heavy metal pollution of tungsten tailings on the diversity of ground surface arthropods in eucalyptus forests of different ages,three eucalyptus forests of different ages in and around the tailings area were selected as research sites,and an eucalyptus forest away from the tailings was used as a control site.The ground surface arthropods were captured to be studied for their community diversity,similarity and correlation with soil environmental factors.The results showed that:a total number of 907 individual ground surface arthropods with 14 orders and 39 families were captured in the 1-year-old,7-year-old,and 26-year-old eucalyptus forests;a total number of 1039 individual ground surface arthropods with 14 orders and 58 families were captured from the control eucalyptus forest.The numbers of individuals and groups of ground surface arthropods in eucalyptus forests showed an increasing trend in the order of the 1-year-old,7-year-old and 26-year-old eucalyptus forests and the control one.The dominant groups shared by the four eucalyptus forests were Araneae and Hymenoptera.The number of groups,number of individuals,richness index and diversity index of the ground surface arthropods of the control eucalyptus forest were significantly higher than those of other eucalyptus forests.Such numbers of the sample plot of the 26-year-old eucalyptus forest came in second,and both were significantly higher than those of the 7-year-old one and the 1-year-old one.The numbers of the 1-year-old eucalyptus forest were the lowest.The nMDS ordering and SIMPER similarity analysis showed that there were obvious differences in the community structure of the ground surface arthropods among the 1-year-old,7-year-old,26-year-old eucalyptus forests and the control one.Pearson correlation analysis showed that the number of species,number of individuals,richness index,diversity index of the ground surface arthropods and organic matter content,TN,water content,pH and available phosphorus content in the eucalyptus forests were significantly positively correlated.At the same time,there was a significant negative correlation with Zn,Cu,As,Cd and Pb.Heavy metal pollution in tungsten tailings has led to a decrease in soil physiochemical factors and vegetation distribution in the surrounding habitats,and a decrease in the diversity of ground surface arthropod communities.But in ecological restoration,the number of individuals,number of groups and diversity index of ground surface arthropods have showed an increasing trend with the increase of the ages of the eucalyptus forests.