摘要
为探讨不同植被类型对喀斯特地区土壤微生物的影响,进一步研究植被恢复对喀斯特地区土壤生态系统功能的影响.以粤北地区典型植被类型(针叶林、阔叶林和天然草地)土壤为研究对象,对不同植被类型土壤的理化性质和细菌群落结构与功能进行研究,分析粤北喀斯特山区中不同植被类型土壤的理化性质、细菌群落多样性和功能组成的差异.结果显示:在细菌群落多样性方面,除了针叶林的均匀度和系统发育多样性水平较低,其他无显著差异.土壤细菌的群落组成在不同植被类型中具有显著差异,土壤理化参数如pH值、含水率、铵态氮、硝态氮、总氮、总磷和有机质对土壤细菌群落组成有显著影响.草地土壤的pH值接近中性,且显著高于针叶林和阔叶林土壤,草地土壤的氮、磷、有机质含量也更高.根据原核生物分类单元功能注释功能预测结果,不同植被类型土壤中,化能异养表达量最高,氮循环相关的功能中固氮功能表达量较高,且在不同植被类型土壤中产生了显著差异,总氮、总磷、pH值和土壤含水率是导致这一差异的主要环境因子.综上,喀斯特地区的植被恢复以及林-草之间的生态演替可能会影响土壤细菌群落结构与潜在功能,进而影响土壤生态系统功能.
Abstract
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.
维普
万方数据