Impact Of Heavy Metal Pollution On Soil Animal Community In Huainan

Soil animals was sensitive environmental indicators and had become a hot topic in soil ecological restoration.The level of soil contamination was determined in Huainan by the analysis of soil heavy metal content.We selected eight sampling sites for analyzing the impact of heavy metal pollution on soil animals communities.The results showed that 1346 soil animals which we collected belonged to 4 phyla,8 classes,23 groups.The dominant groups were rove beetle,Acarina,Hymenoptera.The eight groups such as Collembola,Diptera,Coleoptera,Hemiptera,Chilopoda,Earthworm,Diplura,Coleoptera(Larva)were common groups,while the others groups were rare.Heavy metal pollution had a significant influence on soil animal community.With the increasing of the heavy metal pollution level,the individual numbers and groups of soil animals decreased,the evenness and diversity of community were also declined,while the dominance index increased.There were positive correlations between diversity index and evenness index,negative correlations between the diversity index and dominance index,between evenness index and dominance index.Sampling sites E for the clean area.Sampling sites A for the light pollution area.Sampling sites B for the moderate pollution area.Sampling sites C,D for the severe pollution area.Sampling sites F,G,H for the serious pollution area.In heavy metal pollution soil sampling sites(A,B,C,D,F,G,H),the individual numbers and groups of dominant and common groups have the trend of obvious reduction,some kinds of soil animals even become rare.Particularly,some rare groups such as Protura,Symphyle Dermaptera,have sensitive influence for heavy metal pollution,their changes in all kinds of pollution area is very obvious.By calculating Bray-Curtis cluster analysis,the eight sampling sites can be divided into four groups: Sampling site A and B as one group,sampling site C and D as one group,sampling site F,G and H as one group,sampling site E as one group and similarity with other sites were low.The comprehensive pollution index of all the sampling sites and several soil physicochemical properties index has no obvious correlation.But,in the non-heavy metal polluted areas,the individual numbers and groups of soil animal community and the physicochemical properties index of soil have close positive correlation.In sampling sites A,B,C,D,E which heavy metal contamination is not serious,with the increasing of soil depth,the individual numbers and groups of soil animal community were decreased.This trend is particularly obvious in the light pollution area.While in the serious pollution area,this trend tends to be gentle.There are even the reverse distribution phenomenon in layer a(0-5cm)and layer b(5-10 cm).