土壤团聚体与微生物相互作用研究

Research review on soil aggregates and microbes

土壤团聚体是土壤生态系统中重要的组成部分,影响着土壤的物理、化学和生物学性质,它的形成是生命和非生命物质共同作用的结果,其中微生物是形成土壤团聚体最活跃的生物因素。土壤团聚体和微生物是不可分割的,前者是后者存在的场所,后者是前者形成的主要因素。土壤微生物通过直接改造或物理缠绕、分泌有机物或者改变土壤疏水性等机制影响土壤有机质的分异和土壤团聚结构的形成和稳定;同时,土壤团聚结构的动态变化又反馈控制土壤微生物活动和土壤有机质组分的分异作用,使得土壤团聚结构-土壤有机质组分-微生物群落结构的动态变化之间存在耦合作用。该文首先综述了微生物在土壤团聚体形成中的作用,发现不同种类的微生物对不同粒级团聚体的形成和稳定机制不同,真菌对大团聚体的形成和稳定性起重要作用,来自于植物和微生物的多糖在土壤微团聚体的形成和稳定中起关键作用;其次,微生物在不同粒径团聚体中的组成和分布不同,大团聚体中以真菌为主,微团聚体中以细菌为主;最后探讨了目前应用广泛的研究团聚体中微生物的技术手段和未来研究思路,以期为今后的科学研究提供理论和方法上的指导。

Soil aggregates are the main soil components and significantly influence soil physical, chemical and biological characteristics. The formation of soil aggregates are the joint effects of living and non-living matters, and the microbes are the most active biological factors. As soil microbes reside in aggregates and affect the formation of soil aggregates, the microbe and aggregate are inseparable. Soil microorganism control the fractionation of soil organic matter and the stability of soil aggregates by directly transform or physically intertwine, secretion of organic matter or change the soil hydrophobic property. Meanwhile, the dynamic changes in soil aggregate structure determine soil microbial activities and the fractionation of soil organic matter, making there have coupling interactions among soil aggregate structure, soil organic matter fractions and changes of soil microbial community structure.Firstly, this paper summarizes the roles of soil microbes in the formation of soil aggregates, different type of soil microbes have different mechanism on the formation and stabilization of soil aggregates. Fungi is vital important for the formation and stabilization of large soil aggregate, but the soil polysaccharide derived from the plants and soil microbes are very essential for the small aggregate. Secondly, the variety and distribution of soil microbes are different in different size of soil aggregates, fungi reside in large aggregates, and bacteria mainly distribute in small aggregates. Finally, widely used technologies and methods in studying the microbes in soil aggregates and further research issues were proposed, which would provide supports for future studies.