生物多样性 ›› 2026, Vol. 34 ›› Issue (7): 26008.  DOI: 10.17520/biods.2026008  cstr: 32101.14.biods.2026008

• 土壤生物多样性专题 • 上一篇    下一篇

热带土地利用变化下土壤微食物网多样性的非同步响应与网络重组

桂奇慧1,2, 徐国瑞1,*()   

  1. 1 中国科学院西双版纳热带植物园热带森林生态学实验室, 云南勐腊 666303
    2 中国科学院大学, 北京 100049
  • 收稿日期:2026-01-09 接受日期:2026-03-30 出版日期:2026-07-20 发布日期:2026-09-21
  • 通讯作者: 徐国瑞
  • 基金资助:
    云南省基础研究专项(202301AT070355);云南省重点研发计划(202403AC100028);国家自然科学基金(32371716);质兰基金会项目(2023100521A)

Asynchronous response and network reorganization of soil micro-food web diversity under tropical land use change

Qihui Gui1,2, Guorui Xu1,*()   

  1. 1 CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
    2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2026-01-09 Accepted:2026-03-30 Online:2026-07-20 Published:2026-09-21
  • Contact: Guorui Xu
  • Supported by:
    Basic Research Program of Yunnan Province(202301AT070355);Key Research and Development Program of Yunnan Province(202403AC100028);National Natural Science Foundation of China(32371716);Zhilan Foundation Project(2023100521A)

摘要:

热带土地利用变化引发的生物多样性丧失与功能退化备受关注, 但地下多营养级(细菌、真菌、原生动物、线虫)土壤微食物网的响应机制、网络拓扑适应策略及跨营养级关联演变仍缺乏系统认知。本研究在西双版纳选取干扰递增的4种典型土地利用类型(原始林、次生林、开阔生境、橡胶(Hevea brasiliensis)林), 基于16S rRNA与18S rRNA高通量测序技术调查4个营养级的群落结构, 并结合共现网络分析(评估复杂性与模块度)和全局Mantel检验开展系统研究。结果表明: (1)微食物网呈现显著的非同步响应, 橡胶林中细菌多样性维持较高水平, 而高营养级原生动物多样性随干扰加剧显著下降, 线虫多样性虽保持稳定, 但群落组成发生明显变化, 杂食性的丝尾属(Oxydirus)线虫在次生林和橡胶林中均未被检出; (2)网络重组策略发生分化, 低营养级(细菌、真菌)随干扰加剧通过提高模块度维持稳定性, 而土壤原生动物网络显著简化(连接数丧失近80%), 橡胶林线虫网络连接高度集中于少数节点并发生致密化; (3)环境驱动机制发生严重解耦, 原始林微食物网构建由土壤物理结构(粒径分布与孔隙度)主导, 而橡胶林随土壤物理状况退化(粘粒流失、总孔隙度下降), 高营养级群落构建与环境因子显著解耦, 主导驱动力由确定性环境筛选转向生态漂变。本研究表明土壤物理微生境退化是触发高营养级网络简化的关键因素, 强调仅凭微生物评估生态健康具有局限性, 为热带人工林生态修复与多营养级生物多样性保护提供了科学依据。

关键词: 土地利用变化, 土壤微食物网, 网络分析, 非同步响应, 橡胶林, 西双版纳, 多营养级

Abstract

Aims: Biodiversity loss and functional degradation caused by tropical land use change have attracted widespread attention. However, a systematic understanding of the response mechanisms, network topological adaptation strategies, and cross-trophic linkage dynamics of belowground multi-trophic soil micro-food webs (bacteria, fungi, protozoa, and nematodes) remains lacking. This study aimed to reveal the response patterns of each trophic level in belowground soil micro-food webs to intensive land use, their network structural reorganization strategies, and the underlying environmental driving mechanisms.
Methods: In Xishuangbanna, four typical land use types representing an increasing gradient of disturbance (primary forest, secondary forest, open habitat, and rubber plantation) were selected. Based on 16S rRNA and 18S rRNA high-throughput sequencing technologies, community structures across four trophic levels were investigated, and a systemic study was conducted combining co-occurrence network analysis (evaluating complexity and modularity) with global Mantel tests.
Results: (1) The micro-food web exhibited significant asynchronous responses, where bacterial diversity remained high in rubber plantations, whereas the diversity of higher-trophic protozoa decreased significantly with intensifying disturbance, and although nematode diversity remained stable, the omnivorous genus Oxydirus was not detected in secondary forest and rubber plantations. (2) Network reorganization strategies diverged, with lower trophic levels (bacteria and fungi) maintaining stability under intensifying disturbance by increasing modularity, whereas soil protozoa networks were markedly simplified (protozoan connections lost nearly 80%), and the nematode network in rubber plantations densified with connections becoming highly concentrated on a few nodes. (3) Environmental driving mechanisms underwent severe decoupling, where micro-food web assembly in primary forests was dominated by soil physical structure (particle size distribution and porosity), but with the degradation of soil physical conditions in rubber plantations (clay loss and total porosity decline), the assembly of higher-trophic communities became significantly decoupled from environmental factors, shifting the dominant driving force from deterministic environmental filtering to ecological drift.
Conclusion: This study emphasizes that the degradation of soil physical microhabitats is the key factor triggering the simplification of higher-trophic networks, indicates the limitations of relying solely on microorganisms to assess ecosystem health, and provides a scientific basis for ecological restoration and multi-trophic biodiversity conservation in tropical plantations.

Key words: land use change, soil micro-food web, network analysis, asynchronous response, rubber plantations, Xishuangbanna, multi-trophic levels