Ecological Characteristics Of Soil Microorganismsand Soil Qualityu Evaluation In The Opencast Coalmine Dump

Coalmine dump is born with coal mining. Protecting ecological environment of coalmine dump is the fundamental way to realize sustainable development in mining area. A rational and objective method of evaluating soil environment has great significance in selecting the best restoration measures in coalmine dump. In this paper, planted forests (Ulmus pumila, Robinia pseudoacacia and Amorpha fruticosa), engineering reclamation and natural grassland were selected as restoration land, while bare land was used as control in Haizhou opencast coalmine dump. In order to find out the best restoration measure, the influences of ecological restoration measures on soil physical and chemical properties, microbe quantities, bacterial gene diversity and soil enzyme activities were studied. As a new technique for DNA fingerprinting, denaturing gradient gel electrophoresis was used for soil bacterial community analysis.The results showed that ecological restoration could effectively improve the soil nutrient contents, soil microbial numbers, soil microbial biomass, soil microbial quotient, soil enzyme activities and soil pH value in opencast coalmine dump. It could effectively reduce soil basal respiration and metabolic quotient. Planted forests land was the most significant in improving soil quality, but engineering reclamation was the worest, and trees were better than shrubs in coalmine dump. Engineering reclamation and planted forests could more significantly improve soil bacterial gene divisities than natural grassland. Correlation analysis disclosed that there was significant correlation between microbial indicators and soil nutrient, these biology indicators could evaluate soil fertilities.It was discussed about soil quality in the process of ecological restoration with the principal component analysis. The mathematical models for evaluating soil quality were structured. Soil quality was classified and sensitive microbiology indicators for evaluating soil quality in coalmine dump were found out with the clustering analysis and the stepwise regression analysis. These could provide scientific data for the protection of ecosystem in coalmine dump.