Kang Peng, Pan Yaqing, Yang Pan, Hu Jinpeng, Zhao Tongli, Zhang Yaqi, Ding Xiaodong, Yan Xingfu
School of Biological Science and Engineering, North Minzu University, Yinchuan, Ningxia, China.
Key Laboratory of Ecological Protection of Agro-pastoral Ecotones in the Yellow River Basin, National Ethnic Affairs Commission of the People's Republic of China, Yinchuan, Ningxia, China.
Front Microbiol. 2022 Oct 10;13:1018077. doi: 10.3389/fmicb.2022.1018077. eCollection 2022.
Soil microbes act as "players" in regulating biogeochemical cycles, whereas environmental heterogeneity drives microbial community assembly patterns and is influenced by stochastic and deterministic ecological processes. Currently, the limited understanding of soil microbial community assembly patterns and interactions under temperate forest stand differences pose a challenge in studying the soil microbial involvement during the succession from coniferous to broad-leaved forests. This study investigated the changes in soil bacterial and fungal community diversity and community structure at the regional scale and identified the pathways influencing soil microbial assembly patterns and their interactions. The results showed that broad-leaved forest cover in temperate forests significantly increased soil pH, and effectively increased soil water content, total carbon (TC), total nitrogen (TN), and total phosphorus (TP) contents. Both soil bacterial and fungal alpha diversity indices were correlated with soil physicochemical properties, especially in broad-leaved forest. The bacterial and fungal community composition of coniferous forest was dominated by deterministic process (bacteria: 69.4%; fungi: 88.9%), while the bacterial community composition of broad-leaved forest was dominated by stochastic process (77.8%) and the fungal community composition was dominated by deterministic process (52.8%). Proteobacteria, Acidobacteriota, Actinobacteriota, and Verrucomicrobiota were the dominant phyla of soil bacterial communities in temperate forests. Whereas Ascomycota, Mortierellomycota, Basidiomycota, and Rozellomycota were the dominant phyla of soil fungal communities in temperate forests. Most members of dominant phylum were regulated by soil physical and chemical properties. In addition, the succession from temperate coniferous forest to broad-leaved forest was conducive to maintaining the complex network of soil bacteria and fungi, and the top 20 degree of the major taxa in the network reflected the positive response of microbial interactions to the changes of soil nutrients during forest succession. This study not only shows the mechanism by which species differences in temperate forests of northern China affect soil microbial community assembly processes, but also further emphasizes the importance of the soil microbiome as a key ecosystem factor through co-occurrence network analysis.
土壤微生物在调节生物地球化学循环中扮演着“参与者”的角色，而环境异质性驱动着微生物群落的组装模式，并受到随机和确定性生态过程的影响。目前，对于温带林分差异下土壤微生物群落组装模式及相互作用的认识有限，这给研究针叶林向阔叶林演替过程中土壤微生物的参与情况带来了挑战。本研究在区域尺度上调查了土壤细菌和真菌群落多样性及群落结构的变化，并确定了影响土壤微生物组装模式及其相互作用的途径。结果表明，温带森林中的阔叶林显著提高了土壤pH值，并有效增加了土壤含水量、总碳（TC）、总氮（TN）和总磷（TP）含量。土壤细菌和真菌的α多样性指数均与土壤理化性质相关，尤其是在阔叶林中。针叶林的细菌和真菌群落组成以确定性过程为主（细菌：69.4%；真菌：88.9%），而阔叶林的细菌群落组成以随机过程为主（77.8%），真菌群落组成以确定性过程为主（52.8%）。变形菌门、酸杆菌门、放线菌门和疣微菌门是温带森林土壤细菌群落的优势门类。而子囊菌门、被孢霉门、担子菌门和罗兹菌门是温带森林土壤真菌群落的优势门类。优势门类的大多数成员受土壤理化性质调控。此外，从温带针叶林到阔叶林的演替有利于维持土壤细菌和真菌的复杂网络，网络中主要类群的前20度节点反映了森林演替过程中微生物相互作用对土壤养分变化的积极响应。本研究不仅揭示了中国北方温带森林物种差异影响土壤微生物群落组装过程的机制，还通过共现网络分析进一步强调了土壤微生物组作为关键生态系统因子的重要性。
