喀斯特不同植被类型土壤细菌群落与功能特征.

In this study, we sought to determine the effects of different vegetation types on soil microorganisms in karst areas of China, and to examine the impacts of vegetation restoration on soil ecosystem function in these areas. For the purposes of the study, we used soil collected from typical vegetation types (coniferous forest, broad-leaved forest, and natural grassland) in mountainous karst areas of northern Guangdong, among which, we analyzed differences in soil physicochemical properties, bacterial community diversity, and functional composition. Results showed that in terms of bacterial community diversity, there were no significant differences among the different vegetation types' soil with the exception being those of coniferous forests, which were characterized by lower levels of evenness and phylogenetic diversity. The community composition of soil bacteria was differed significantly among the different vegetation types, and soil physicochemical parameters (pH value and the contents of water, ammonia salts, nitrate, total nitrogen, total phosphorus, and organic matter) had a significant influence on the composition of the soil bacterial community. The pH value of grassland soil was close to neutral, and was significantly higher than that of the soils of coniferous forest and broad-leaved forest land. Similarly, grassland soil was characterized by higher contents of nitrogen, phosphorus, and organic matter. Results obtained based on functional annotation of prokaryotic taxa functional prediction revealed that chemoheterotrophic expression was highest in soils of different vegetation types. Nitrogen fixation was higher in nitrogen cycle-related functions, and there were significant differences in different types of soils, with total nitrogen, total phosphorus, pH value, and soil moisture being identified as the main environmental factors contributing to these differences. In conclusion, differences in vegetation restoration and ecological succession among forests and grasslands in karst areas may influence soil bacterial community structure and potential functions, and thus have differing effects on soil ecosystem functions. [ABSTRACT FROM AUTHOR]