Wang Haocai, Crowther Thomas W, Isobe Kazuo, Wang Hang, Tateno Ryunosuke, Shi Weiyu
Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station, School of Geographical Sciences, Southwest University, Chongqing, China.
Department of Environment Systems Science, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland.
Mol Ecol. 2025 Apr;34(8):e17723. doi: 10.1111/mec.17723. Epub 2025 Mar 20.
Natural restoration is an effective approach for restoring degraded ecosystems, yet the successional patterns and assembly mechanisms of aboveground (litter layer) and belowground (topsoil) microbial communities remain poorly understood. We applied the niche conservatism framework to investigate niche partitioning, successional patterns and community assembly processes of microbial communities in the litter and topsoil layers during long-term vegetation restoration in southwestern China. The results showed that, during vegetation succession, the potential source communities of microbial communities in the litter layer gradually shifted from being dominated by the topsoil to being dominated by the litter. Fungal communities had a significantly higher proportion of external immigrants (> 80%) than bacteria (> 40%) and archaea (< 20%). During succession, bacterial and fungal communities in the litter and topsoil layers underwent niche differentiation, displaying a divergent succession pattern, while archaeal communities showed niche overlap, following a convergent pattern driven by stochastic processes. Additionally, the dispersal rate (m) and β-diversity turnover rate (slope) of bacterial and fungal species in the litter were significantly lower than in the topsoil, with community assembly being more influenced by deterministic processes in the litter. This study reveals that higher habitat specialisation in the litter imposes stronger filtering effects on the colonisation of most microbial groups, particularly fungal communities, highlighting the role of strategy differentiation in shaping microbial communities.
自然恢复是恢复退化生态系统的有效途径，然而，地上（凋落物层）和地下（表土层）微生物群落的演替模式和组装机制仍知之甚少。我们应用生态位保守性框架，研究了中国西南地区长期植被恢复过程中凋落物层和表土层微生物群落的生态位分化、演替模式和群落组装过程。结果表明，在植被演替过程中，凋落物层微生物群落的潜在源群落逐渐从以表土层为主转变为以凋落物为主。真菌群落的外来移民比例（>80%）显著高于细菌（>40%）和古菌（<20%）。在演替过程中，凋落物层和表土层的细菌和真菌群落发生了生态位分化，呈现出不同的演替模式，而古菌群落则表现出生态位重叠，遵循由随机过程驱动的趋同模式。此外，凋落物中细菌和真菌物种的扩散率（m）和β-多样性周转率（斜率）显著低于表土层，群落组装受凋落物中确定性过程的影响更大。本研究表明，凋落物中较高的栖息地专一性对大多数微生物类群，特别是真菌群落的定殖施加了更强的过滤作用，突出了策略分化在塑造微生物群落中的作用。
