民勤绿洲退耕区次生草地演变过程中土壤微生态机理研究
Study on the Soil Microecological Mechanism during the Evolution of Secondary Grassland in the Returned Farmland Area of Minqin Oasis

干旱绿洲区耕地大面积退耕后,不采取任何农业管理措施，则易形成荒漠草原或漠境草原，可能导致次生草地向裸露化或沙漠化发展，不利于绿洲生态系统的安全与稳定。土壤微生物多样性是衡量生态系统功能恢复与维持的敏感而关键指标，直接影响土壤生产力，关乎生态系统结构和功能的稳定性。因此，从微生态学角度出发，研究不同年限退耕区次生草地土壤微生物多样性、功能菌群及其变化机理显得尤为重要。本项目拟采用时空替代法和现代分子生物学技术，结合土壤理化特性、土壤酶活性及50多年的气象、水文、植被、风蚀等资料，对民勤绿洲不同年代(1年至50多年)退耕区次生草地土壤微生物的结构多样性、功能多样性和遗传多样性进行测定和系统分析，阐明民勤绿洲退耕区次生草地土壤微生物变化规律及其与植被、土壤因子的相关性，探讨土壤微生物功能菌群在次生草地演变过程所起的作用，为开发微生物资源和保护荒漠绿洲退耕区次生草地及生态系统修复提供理论依据。
After a large area of cultivated land in arid oasis areas is returned to farming, without taking any agricultural management measures, it is easy to form desert steppe or desert steppe, which may lead to the development of secondary grassland to nudity or desertification, which is not conducive to the safety and stability of the oasis ecosystem. Soil microbial diversity is a sensitive and key indicator for measuring the restoration and maintenance of ecosystem functions. It directly affects soil productivity and is related to the stability of ecosystem structure and function. Therefore, from the perspective of microecology, it is particularly important to study the soil microbial diversity, functional flora and their change mechanisms in secondary grassland areas of different years. This project plans to use the spatiotemporal substitution method and modern molecular biology technology, combined with soil physical and chemical characteristics, soil enzyme activity and more than 50 years of meteorological, hydrological, vegetation, wind erosion and other data, to return farmland to Minqin Oasis in different years (from 1 year to more than 50 years ago). To measure and systematically analyze the structural diversity, functional diversity and genetic diversity of soil microorganisms in the secondary grassland area of Minqin Oasis, clarify the change patterns of soil microorganisms in the secondary grassland area of Minqin Oasis and its correlation with vegetation and soil factors, and explore the soil microbial diversity. The role of microbial functional flora in the evolution of secondary grassland provides a theoretical basis for the development of microbial resources and the protection of secondary grassland and ecosystem restoration in desert oasis returned farmland areas.