Study On Basic Characteristics Of Biological Soil Crust In Coal Mine Area During Vegetation Restoration

Biological soil crusts are widespread in arid and semi arid regions; its research has become one of the biology research frontiers in arid and semi arid regions. Composition of biological soil crusts of moss and algae are common pioneer colonization of plants, they have an important influence on soil nutrient cycling, vascular plant germination and growth ecological process for damaged ecosystem restoration process. In order to know the change of the basic characteristics of biological soil crust and soil quality, and clear the response characteristics of moss, algae biological soil crust photosynthetic carbon fixation on heat and water factors in the process of vegetation restoration in mining area. Biological soil crusts in vegetation restoration zone of damaged ecosystem are the research object, through the investigation on the types composition, coverage, thickness of biological soil crusts to reflect the basic characteristics of biological soil crusts and through the determination of soil physical and chemical properties and soil enzyme activity to reflect the changes of soil quality in the process of vegetation restoration. Two types of biological soil crusts(moss crust and algae crust) as materials, study the response of biological soil crusts photosynthesis activity on water and heat factors by controlling the temperature and moisture in the artificial climate chamber and using Li-6400(tufted leaves room) photosynthetic apparatus. The results are as follows:(1) the species composition of biological soil crusts are mainly moss crust and algae crust, the average coverage has reached more than 50%, the average thickness has exceed more than 0.45 cm. The total coverage of BSCs is arbor-grass type > grass type > arbor-shrub-grass type > arbor type, and the total thickness of the BSCs is arborshrub-grass type > arbor-grass type > arbor type > grass type. These showed that the establishment of artificial vegetation in favor of BSCs colonization and development of degraded ecosystem in mining area, especially in the grass and shrub and arbor herb type effect is the best.(2) The optimal temperature of carbon sequestration activity of moss and algae crusts were 20~25℃ and 15~20℃, the optimal simulated precipitation were 2mm. Carbon sequestration activity of moss crusts was significantly higher than that of algae crust. Temperature and moisture are significant effects on the carbon sequestration activity of biological soil crusts, the interaction effect between temperature, moisture and crust type also influence the carbon sequestration activity of biological soil crusts.(3) BSCs can improve physical and chemical properties and soil enzyme activity of the surface soil, the physicochemical properties and enzyme activity of all samples in 0-10 cm level were higher than 10-20 cm level. The different vegetation types of BSCs improved physicochemical properties and soil enzyme activity level is arbor-shrub-grass type > arbor-grass type > arbor type > grass type. With the increase of vegetation restoration years, BSCs on the surface colonization and growth, the soil p H value decreased, the soil nutrient content and soil enzyme activity increased, which is conducive to the improvement of soil properties, In turn, further promote the growth of BSCs.