Study On The Soil Microbial Of Two Kinds Of Copper Mining Wastelands

Mining wasteland refers to useless or unhelpful land,which is destroyed,occupied and polluted due to people mining activities.Generally,it is divided into three types:tailing wastelands,waste rockdumps and mining subsidence aera.The recovery of mining wasteland soil ecosystem,not only refers to recover the ground vegetation,but also includes the restoration of the soil microbial community structure.Two different types of copper mining wasteland,namely copper tailings from Fenghuangshan xiangsigu and copper waste rockdump wastelands from shizishan in Tongling Anhui province were studied in this paper.Physicochemical properties,heavy metals content and soil enzyme activity of two copper mining wastelands were determined and analysed,meanwhile,soil bacterial community composition and abundance of two wastelands in different seasons were determined by using high-throughput sequencing technologies.Arbuscular mycorrhizal(AM)fungi from mining wasteland plant rhizosphere was isolated and identified by using the optical microscope and electron microscope.It will contribute to illustrate the environmental effects on the bacterial community in copper mining watelands and the difference of the microbial community structure in two kinds of copper mining wastelands.This paper provides theoretical basis for the restoration and reconstruction of the soil ecosystem in mining wastelands.The main results were as follows:1.Physicochemical properties analysis of two copper mining wastelands indicated that low nutrient component and high heavy metal content of copper were the main factors which led that plants cannot or were difficult to settle on copper mining wastelands,The two main factors also influenced the microbial species and community structure on the copper mining wastelands.The contents of total nitrogen,total phosphorus,organic matter in the Shizishan copper mining wasteland substates were higher about 3.26,1.81 and 1.67 times than that of tailings wasteland.The concentration of total Cu reached to 7512.30 mg/kg,which was higher 3.34 times than that of the tailing wastelands.Plant establishment helps to improve the activity of soil enzyme,Shizishan copper wasteland was higher than the copper tailings wasteland.2.Soil bacteria in two kinds of mining wastelands have been studied by high-throughput sequencing.223706 gene sequences for mining wastelands in autumn were obtained.1909 OTUs at 97% similarity level were gained.The bacteria OTUs were mainly assigned into 25 different known phyla,32 classes and 160 genera.There are 5 dominant bacteria(relative abundance>5%)in the tailing wasteland,Proteobacteria,Acidobacteria,Chloroflexi,Bacteroidetes,and Parcubacteria,respectively;there were 6 dominant bacteria in the copper wasteland,Proteobacteria,Acidobacteria,Chloroflexi,Actinobacteria,Verrucomicrobia and Bacteroidetes respectively.Proteobacteria,Acidobacteria,Chloroflexi and Bacteroidetes were the dominant bacteria in the fall of two mining wastelands in autumn.A total of 138803 gene sequences were obtained for mining wastelands in summer,and at 97% similarity level clustering received 2685 OTUs.The bacteria OTUs were mainy assigned into 21 different known phyla,31 classes and 109 genera.There are 3 dominant bacteria(relative abundance>5%)in the tailing wastelands,respectively Proteobacteria,Acidobacteria and Actinobacteria;there are 5 dominant bacteria in the copper wastelands,respectively Proteobacteria,Acidobacteria,Bacteroidetes,Gemmatimonadetes and Verrucomicrobia.Proteobacteria and Acidobacteria were the dominant bacteria in the fall of two mining wastelands in summer.3.The relative abundance of soil bacteria was affected by soil physicochemical properties,soil enzyme and heavy metal elements.Acidobacteria,Bacteroidetes and Actinobacteria relative abundance and soil physicochemical properties have good correlation;the relationship between the protease activity and the dominant bacteria was good;Cu,Cr and Acidobacteria,Bacteroidetes and Armatimonadetes relative abundance was negative correlation,with the positively correlated on Actinobacteria,Chloroflexi and Proteobacteria,while Pb,Zn and Cd with these bacteria phyla correlation was opposite,indicating that the tolerance of different bacteria to heavy metals were distinctive,heavy metal elements in the presence of a certain selectivity for bacterial growth and reproduction;the influence of different heavy metal elements in soil bacterial populations were different,but the effect of total amount and available heavy metals on soil bacteria is the same.4.The plant Elsholtzia splendens,Artemisia capillaries and Commelina communis of copper wasteland can form good symbiotic relationships with AM fungi and there was a clear colonization and infection in plant rhizosphere.22 kinds of AM fungi were isolated from the rhizosphere soil,which Glomus sp.13 strains,Acaulospora sp.6 strains,Funneliformis sp.2 strains and Scutellospora sp.1 strains.Separated by electron microscope isolated and identified 14 Strains of fungal spores,which Glomus sp.11 strains,Acaulospora sp.3 strains.Glomus sp.and Acaulospora sp.are dominant in this area.In all 22 AM fungi species were appeared in different plants rhizosphere,this indicates that host plant species significantly affect the AM fungal community structure.In the natural state of copper tailing wasteland,the plant was not found to settle,so the isolation and identification of AM fungal spores were not carried out.However,the soil bacteria group is rich,mainly include Proteobacteria,Acidobacteria,Actinobacteria and Chloroflexi,et al.The diversity of soil bacterial community in the abandoned copper tailings provides a certain potential for the reconstruction and restoration of the vegetation on the ground.