| 干旱半干旱区草地生态系统土壤细菌群落组装对土壤深度的响应 |
| 摘要点击 1164 全文点击 9 投稿时间：2025-07-14 修订日期：2025-11-05 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 干旱半干旱区 共现网络 细菌多样性 群落组装 确定性过程 |
| 英文关键词 arid and semi-arid region co-occurrence networks bacterial diversity community assembly deterministic processes |
| DOI 10.13227/j.hjkx.202507188 |
|
| 中文摘要 |
| 土壤细菌群落对生态系统过程影响至关重要，但其组装过程对不同土层的响应尚不清晰. 厘清草地生态系统土壤细菌群落的共现网络与组装，对于理解微生物生态系统过程具有关键意义. 采用16S rRNA和ITS扩增子的高通量测序技术，研究草地生态系统土壤深度梯度对土壤细菌群落组装的影响. 结果表明，放线菌门、变形菌门、绿弯菌门和酸杆菌门是不同草原土壤的优势细菌门类. 细菌多样性从表层土壤到底层土壤逐渐降低. 共现网络拓扑参数（网络的边、节点和类聚系数）都是随着土壤深度的增加而减小，表层土壤细菌群落表现出更高的模块化和群落之间有更多的正相关关系. 零模型分析揭示确定性过程（尤其是均匀选择）对细菌群落的组装起主导作用，但其影响随深度增加而减弱，而随机过程（如扩散限制）则从表层土壤到深层土壤逐渐增强. 分段结构方程分析表明，非生物因素（气候、养分）和生物因素（种间相互作用）对细菌群落组装的影响表现出深度依赖模式. 研究为干旱半干旱区草地生态系统土壤细菌群落的垂直分层提供了新参考视角，并加深了人们对气候变化下成土过程以及异质土壤环境中微生物适应策略的理解. |
| 英文摘要 |
| Soil bacterial communities play a crucial role in ecosystem processes， yet their assembly dynamics across different soil horizons remain poorly understood. Elucidating the co-occurrence networks and assembly patterns of soil bacterial communities in grassland ecosystems is essential for comprehending microbial ecosystem processes. Using high-throughput sequencing of 16S rRNA and ITS amplicons， we investigated the effects of soil depth gradients in grassland ecosystems on bacterial community assembly. The results indicated that Actinobacteria， Proteobacteria， Verrucomicrobia， and Acidobacteria were dominant bacterial phyla across different grassland soils. Bacterial diversity decreased progressively from surface to deep soil layers. Co-occurrence network topology parameters （edges， nodes， and clustering coefficients） diminished with increasing soil depth， while surface soil bacterial communities exhibited higher modularity and more positive correlations between communities. Zero-model analysis revealed that deterministic processes （particularly uniform selection） dominated bacterial community assembly， though their influence weakened with depth， while stochastic processes （e.g.， diffusion limitation） progressively strengthened from surface to deep soils. Segmented structural equation modeling indicated that both abiotic factors （climate and nutrients） and biotic factors （interspecies interactions） exerted depth-dependent effects on bacterial community assembly. This study provides a novel perspective on the vertical stratification of soil bacterial communities in grassland ecosystems of arid and semi-arid regions， deepening our understanding of soil formation processes under climate change and microbial adaptation strategies in heterogeneous soil environments. |
