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荒漠草原土壤丛枝菌根真菌群落对降水变化的响应

郭蓉1,2, 吴旭东3,4, 张雨2, 康瑞红2, 王一凡2, 王占军3,4, 蒋齐3,4, 俞鸿千3,4, 马琨1,2,4*   

  1. 1宁夏大学生命科学学院,银川 750021;2西北退化生态系统恢复与重建教育部重点实验室,银川 750021;3宁夏农林科学院林业与草地生态研究所,银川 750001;4宁夏农牧交错带温性草原生态系统定位观测研究站,宁夏盐池 751500
  • 收稿日期:2026-01-22 修回日期:2026-03-16 接受日期:2026-04-08
  • 通讯作者: 马琨

Response of soil arbuscular mycorrhizal fungal communities to precipitation changes in the desert steppe

Rong Guo1,2, Xudong Wu3,4, Yu Zhang2, Ruihong Kang2, Yifan Wang2, Zhanjun Wang3, Qi Jiang3,4, Hongqian Yu3, Kun Ma1,2,4*   

  1. 1 School of life sciences, Ningxia University, Yinchuan 750021, China; 

    2 Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in Northwestern China of Ministry of Education, Ningxia University, Yinchuan 750021, China; 

    3 Institute of Forests and Grassland Ecology, Ningxia Academy of Agriculture and Forestry Sciences, Yinchuan 750021, China; 

    4 Observation and Research Station for Temperate Grassland Ecosystems in Agro-Pastoral Transitional Zone of Ningxia, Yanchi, Ningxia 751500, China

  • Received:2026-01-22 Revised:2026-03-16 Accepted:2026-04-08
  • Contact: Kun Ma

摘要: 丛枝菌根(arbuscular mycorrhizal, AM)真菌是陆地生态系统中关键的植物共生体,研究降水变化背景下AM真菌群落特征及其与植被和土壤因子之间的关系,对维持荒漠草原生态系统稳定性具有重要的理论意义。本研究于2019-2021年在宁夏盐池县开展降水控制试验,采用单因素完全随机设计,设置D50(自然降水−50%)、D25(自然降水−25%)、CK(自然降水)、I25(自然降水+25%)和I50(自然降水+50%)5种降水处理,基于Illumina高通量测序技术,并结合Mantel分析、随机森林分析和偏最小二乘路径模型分析,探讨降水格局变化对荒漠草原土壤AM真菌群落多样性、丰富度和组成的影响及其驱动机制。研究结果表明,荒漠草原植被盖度、生物量、Shannon多样性指数对降水变化较为敏感。与CK相比,D50处理下AM真菌Shannon指数、Sobs指数、ACE指数和Chao1指数分别显著降低31.6%、53.3%、62.4%和58.7%;AM真菌优势属相对丰度在不同降水梯度下无显著差异。非度量多维尺度分析表明,降水梯度显著影响AM真菌群落组成。随机森林分析显示,植被群落多样性和盖度是决定AM真菌多样性的首要因素;AM真菌丰富度主要受pH调控;AM真菌群落组成主要受降水与硝态氮影响。偏最小二乘路径模型进一步表明,降水可以通过改变土壤水分对AM真菌群落组成产生直接效应,通过调节植被群落对AM真菌多样性产生间接正效应,并通过改变土壤pH对AM真菌丰富度产生间接正效应。综上,荒漠草原降水变化通过影响植被与土壤因子的耦合关系,进而驱动AM真菌群落结构与组成发生变化。研究揭示了菌根共生系统对降水变化的敏感响应特征,为理解荒漠草原生态系统在气候变化背景下的调控机制提供了新的科学依据。

关键词: 丛枝菌根真菌, 降水梯度, 植物群落, 土壤性质, 荒漠草原, 全球气候变化

Abstract

Aims: Arbuscular mycorrhizal (AM) fungi are key plant symbionts in terrestrial ecosystems. Investigating the responses of AM fungal communities to precipitation changes and their relationships with vegetation and soil factors is of great theoretical importance for understanding the stability of desert steppe ecosystems. 

Methods: A precipitation manipulation experiment was conducted in Yanchi County, Ningxia, China, from 2019 to 2021 using a completely randomized design. Five precipitation treatments were established: D50 (natural precipitation −50%), D25 (natural precipitation −25%), CK (natural precipitation), I25 (natural precipitation +25%), and I50 (natural precipitation +50%). Based on Illumina high-throughput sequencing combined with Mantel analysis, random forest analysis, and partial least squares path modeling (PLS-PM), we examined the effects of altered precipitation regimes on the diversity, richness, and community composition of soil AM fungi in the desert steppe ecosystems and identified their main driving factors. 

Results: Vegetation cover, biomass, and Shannon diversity index of the desert steppe were sensitive to precipitation changes. Compared with CK, the D50 treatment significantly reduced the Shannon, Sobs, ACE, and Chao1 indices of AM fungi by 31.6%, 53.3%, 62.4% and 58.7%, respectively. However, the relative abundances of dominant AM fungal genera did not differ significantly among precipitation treatments. Non-metric multidimensional scaling analysis indicated that precipitation gradients significantly affected AM fungal community composition. Random forest analyses revealed that plant diversity and cover were the primary determinants of AM fungal diversity, AM fungal richness was mainly regulated by soil pH, and AM fungal community composition was primarily influenced by precipitation and NO3-N. The PLS-PM results further showed that precipitation directly affected AM fungal community composition by altering soil moisture, indirectly increased AM fungal diversity through vegetation communities, and indirectly increased AM fungal richness through changes in soil pH. 

Conclusion: Precipitation changes regulate the coupling relationships between vegetation and soil factors, thereby driving shifts in the diversity, richness and composition of AM fungal communities in desert steppe ecosystems. These findings highlight the sensitive response of the mycorrhizal symbiosis system to precipitation variation and provide new insights into the mechanisms underlying the regulation of desert steppe ecosystems under climate change.

Key words: Arbuscular mycorrhizal fungi, precipitation gradient, plant communities, soil properties, desert steppe, global climate change