Clarifying the response of soil microbial communities and their potential functions during succession is of great significance for understanding the biogeochemical processes and the sustainability of forest development. However, the study of microbial community dynamics during the process of succession remains poorly understood in boreal forest ecosystems. Thus, in order to study the dynamics of microbial diversity caused by succession, we adopted the "space instead of time" method and selected four habitats in a national natural reserve (including grassland, birch forest, mixed forest and larch forest) to represent the primary successional sequence of the boreal forest. We used 16S and ITS rRNA gene sequencing to detect bacterial and fungal communities and used FAPROTAX and FUNGuild database to predict bacterial and fungal functional groups. The results showed that forest succession significantly changed the community composition of bacteria and fungi, among which the fungal community was more sensitive to the changes with successional stage. The relative abundance of ectomycorrhizal fungi significantly increased with succession, while the relative abundance of bacterial functional groups involved in the nitrogen cycle did not change significantly, indicating that fungi might play a major regulatory role in the nutrient cycling process during the successional process. In this study, the soil total carbon and total nitrogen were the dominating factors affecting the soil microbial community and the structure of fungal functional groups. Our results suggest that the shifts in fungal community structure and functional groups may play a key role in soil nutrient cycling during boreal ecosystems succession.

阐明土壤微生物群落在演替过程中的响应及其潜在功能，对于理解生物地球化学过程和森林发展的可持续性具有重要意义。然而，在北方森林生态系统中，对演替过程中微生物群落动态的研究仍然知之甚少。因此，为了研究演替引起的微生物多样性的动态变化，我们采用“空间代替时间”的方法，选取了国家级自然保护区内的四个生境（草地、白桦林、混交林和落叶松林）来代表北方森林的主要演替序列。我们使用 16S 和 ITS rRNA 基因测序来检测细菌和真菌群落，并使用 FAPROTAX 和 FUNGuild 数据库来预测细菌和真菌功能群。结果表明，森林演替显着改变了细菌和真菌的群落组成，其中真菌群落对演替阶段的变化更为敏感。外生菌根真菌的相对丰度随着演替而显着增加，而参与氮循环的细菌官能团的相对丰度没有显着变化，表明真菌可能在演替过程中的养分循环过程中起主要调节作用。在这项研究中，土壤总碳和总氮是影响土壤微生物群落和真菌功能群结构的主导因素。我们的研究结果表明，真菌群落结构和功能群的变化可能在北方生态系统演替过程中的土壤养分循环中发挥关键作用。