Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
FEMS Microbiol Ecol. 2019 May 1;95(5). doi: 10.1093/femsec/fiz043.
Forest succession is a central ecological topic due to the importance of its dynamic process for terrestrial ecosystems. However, we have limited knowledge of the relationship between forest succession and belowground microbiota, particularly regarding interactions in the rhizosphere. Here, we determined microbial community structure and biomass using phospholipid fatty acid (PLFA) biomarkers and microbial activity using extracellular enzyme activity in bulk and rhizosphere soils from three successional stages of subtropical forests in eastern China. Principal component analysis of PLFAs indicated distinct soil microbial communities among different successional stages and habitat locations. Specifically for the topsoil, we found the total microbial biomass, bacterial biomass and enzyme activities showed higher levels in the late than early stage, with a significant succession-induced accentuated rhizosphere effect. The increase in total microbial biomass and activity coincided with a net growth in bacterial rather than fungal biomass, indicating a model in which microbial biomass carrying capacity and activity could be affected by the creation or expansion of niches for certain functional group rather than by a rebalancing of competitive interactions among these groups. Furthermore, we demonstrated that forest succession significantly influenced enzyme activity via the changes in microbial biomass, as driven by edaphic factors. Overall, our study deepens the mechanistic understanding of forest recovery by linking soil microbial community and activity along successional chronosequences.
森林演替是一个核心的生态课题，因为其动态过程对于陆地生态系统非常重要。然而，我们对于森林演替和地下微生物群之间的关系知之甚少，特别是对于根际中的相互作用。在这里，我们使用磷脂脂肪酸（PLFA）生物标志物来确定亚热带森林三个演替阶段的土壤微生物群落结构和生物量，以及使用胞外酶活性来确定土壤微生物活性。PLFA 的主成分分析表明，不同演替阶段和生境位置的土壤微生物群落存在明显差异。特别是对于表土，我们发现总微生物生物量、细菌生物量和酶活性在后期比早期阶段更高，具有显著的演替诱导的根际效应增强。总微生物生物量和活性的增加与细菌生物量而非真菌生物量的净增长相一致，这表明微生物生物量承载能力和活性可能受到某些功能群的生境创造或扩展的影响，而不是这些群之间竞争相互作用的再平衡。此外，我们证明了森林演替通过土壤微生物生物量的变化显著影响了酶活性，这是由土壤因素驱动的。总的来说，我们的研究通过沿演替时间序列链接土壤微生物群落和活性，深化了对森林恢复的机制理解。
