Study On Microbial Community Structures And Their Influencing Factors In Opencast Coal Mining Area

As an important fossil fuel,coal plays an important role in China's energy supply.Opencast coal mining is an important method of coal mining,which requires not only the removal of surface vegetation,but also the temporal and spatial transfer of massive earthwork,resulting in the destruction or occupation of large areas of land in the mining area.The longterm opencast coal mining operation has led to the destruction of vegetation,frequent sand and dust weather,and serious soil degradation.Therefore,the ecological security construction in mining areas has become an urgent problem to be solved.In this study,five areas including the undisturbed natural areas,the coal mining areas and dumping areas formed during mining,the grassland and forestland formed after coal mining in the opencast coal mining areas of Wuhai city,Inner Mongolia were selected to analyze soil properties,microbial community structure and the relationship between them.The main results are as follows:(1)There are significant differences of microbial community structure among five different areas of opencast coal mine.The diversity of bacterial and fungal community can be reduced significantly by coal mining activities but increased significantly by vegetation restoration.(2)The soil salinity content in different types of opencast coal mining areas is significantly different.The influence of coal mining activities on the salinization degree of the soil in the opencast coal mine is less,but the influence on the nutrient status,carbon storage,nitrogen storage and enzyme activity of the soil in the opencast coal mine is greater.The coal mining activities lead to the decline of many indexes related to soil properties,and the vegetation restoration measures can mitigate the impact of coal mining activities on soil properties to some extent.Compared with grassland,forest land restoration had better effect on soil properties(3)There are some differences for the relationships between community structure of bacteria,fungi and Arbuscular mycorrhizal fungi(AMF)and soil properties.Among them,soil properties had more influence on the community structure of bacteria and AMF than on the community structure of fungi.The structure of bacterial community is closely related to soil salinity,nutrient status and carbon and nitrogen reservoir characteristics,while the community structure of fungi and AMF is closely related to soil nutrient status.