Tian Huimei, Li Liangzhe, Zhu Yunpeng, Wang Chengcheng, Wu Mengxue, Shen Weixing, Li Chuanrong, Li Kun
Mountain Tai Forest Ecosystem Research Station of State Forestry Administration/Key Laboratory of State Forestry Administration for Silviculture of the Lower Yellow River/Forestry College of Shandong Agricultural University, Tai'an, China.
Research Center for Forest Carbon Neutrality Engineering of Shandong Higher Education Institutions, Tai'an, China.
Front Microbiol. 2025 Mar 18;16:1528028. doi: 10.3389/fmicb.2025.1528028. eCollection 2025.
Black locust ( L.) plantations transition from seedling to multi-generation coppice systems, leading to declines in productivity and biodiversity. However, the structural and functional reorganization of soil fungal communities during this transition remains poorly understood. This study aimed to characterize fungal community dynamics across successional stages of black locust stands and assess their implications for soil health and ecosystem resilience.
Soil fungal communities in three black locust stands (first-generation seedling forest, first- and second-generation coppice forests) were analyzed over one year using ITS high-throughput sequencing. We evaluated fungal diversity, guild composition, and co-occurrence networks, integrating statistical analyses (PERMANOVA, ANOSIM, FUNGuild) and network theory to assess seasonal and successional shifts.
Fungal richness and diversity remained stable across stand types and seasons. However, these factors dramatically altered the soil fungal community structure. Shifts in fungal community composition were observed from seedling to coppice stands: Ascomycota dominance decreased (72.9 to 57.9%), while Basidiomycota increased (6.5 to 11.6%). Significant changes in the relative abundance of certain fungal guilds were observed by both stand conversion and seasonal variation ( < 0.05). However, the overall fungal guilds composition was only significantly affected by the seasonal variation, rather than stand conversion ( > 0.05). Furthermore, saprotrophic fungi dominated in autumn/winter (66.49-76.01%), whereas symbiotic fungi peaked in spring (up to 7.27%). As forests transition from seeding to coppice stands, the percentage of negative edges, average degree, and relative modularity of the fungal community co-occurrence networks all gradually decreased. Those suggested that the conversion of black locust stands decreased the connectivity between fungal species, formed less organized structure, increased homogeneity of function among microbial communities, reduced ecological functionality, and decreased resistance to environmental changes. Seasonal temperature fluctuations further modulated network complexity, with summer samples showing heightened edge density but reduced cooperation.
Our findings suggest that the conversion of forests can significantly shift the soil fungal community structure and assembly, favoring Basidiomycota over Ascomycota and reducing network stability. These shifts signal progressive soil nutrient depletion and functional homogenization, potentially compromising ecosystem resilience. Seasonal guild dynamics highlight fungi's role in nutrient cycling, with saprotrophs driving litter decomposition in colder months. This understanding suggest that forest management practices must prioritise the preservation of early successional stages. This is vital to support diverse fungal communities and complex community networks and ensure the stability, functionality and resistance of fungal communities. Restoration efforts must focus on promoting fungal resilience through targeted soil amendments and habitat diversification to enhance ecosystem stability and functionality.
刺槐（Robinia pseudoacacia L.）人工林从幼苗阶段过渡到多代萌生林系统，导致生产力和生物多样性下降。然而，在这一转变过程中土壤真菌群落的结构和功能重组仍知之甚少。本研究旨在描述刺槐林演替阶段真菌群落动态，并评估其对土壤健康和生态系统恢复力的影响。
利用ITS高通量测序技术，对三个刺槐林分（第一代幼苗林、第一代和第二代萌生林）的土壤真菌群落进行了为期一年的分析。我们评估了真菌多样性、功能群组成和共现网络，结合统计分析（PERMANOVA、ANOSIM、FUNGuild）和网络理论来评估季节和演替变化。
真菌丰富度和多样性在林分类型和季节间保持稳定。然而，这些因素显著改变了土壤真菌群落结构。从幼苗林到萌生林观察到真菌群落组成的变化：子囊菌门的优势度下降（72.9%至57.9%），而担子菌门增加（6.5%至11.6%）。林分转变和季节变化均导致某些真菌功能群相对丰度的显著变化（P<0.05）。然而，真菌功能群的总体组成仅受季节变化的显著影响，而非林分转变（P>0.05）。此外，腐生真菌在秋冬季节占主导（66.49%-76.01%），而共生真菌在春季达到峰值（高达7.27%）。随着森林从播种林转变为萌生林，真菌群落共现网络的负边百分比、平均度和相对模块性均逐渐下降。这些结果表明，刺槐林分的转变降低了真菌物种间的连通性，形成的结构组织性降低，微生物群落间功能同质性增加，生态功能降低，对环境变化的抵抗力下降。季节性温度波动进一步调节了网络复杂性，夏季样本显示边密度增加但合作减少。
我们的研究结果表明，森林转变可显著改变土壤真菌群落结构和组装，担子菌门比子囊菌门更占优势，网络稳定性降低。这些变化标志着土壤养分逐渐耗尽和功能同质化，可能损害生态系统恢复力。季节性功能群动态突出了真菌在养分循环中的作用，腐生菌在较冷月份推动凋落物分解。这一认识表明，森林管理实践必须优先保护早期演替阶段。这对于支持多样的真菌群落和复杂的群落网络，确保真菌群落的稳定性、功能性和抗性至关重要。恢复工作必须专注于通过有针对性的土壤改良和栖息地多样化来促进真菌恢复力，以增强生态系统稳定性和功能性。
