生物多样性 ›› 2022, Vol. 30 ›› Issue (3): 21327.  DOI: 10.17520/biods.2021327

所属专题: 土壤生物与土壤健康

• 研究报告: 微生物多样性 • 上一篇    下一篇

极端干旱对温带荒漠土壤真菌群落和生态网络的影响

徐鹏1,2, 荣晓莹1,*(), 刘朝红3, 杜芳1,2, 尹本丰1, 陶冶1, 张元明1   

  1. 1.中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室, 乌鲁木齐 830011
    2.中国科学院大学, 北京 100049
    3.新疆农业大学草业与环境科学学院, 乌鲁木齐 830052
  • 收稿日期:2021-08-18 接受日期:2021-01-14 出版日期:2022-04-07 发布日期:2022-03-11
  • 通讯作者: 荣晓莹
  • 作者简介:*E-mail: rongxy@ms.xjb.ac.cn
  • 基金资助:
    国家自然科学基金-新疆联合基金重点项目(U2003014);国家自然科学基金(31670007);中国科学院“西部青年学者”项目(2019-XBQNXZ-B-007)

Effects of extreme drought on community and ecological network of soil fungi in a temperate desert

Peng Xu1,2, Xiaoying Rong1,*(), Chaohong Liu3, Fang Du1,2, Benfeng Yin1, Ye Tao1, Yuanming Zhang1   

  1. 1 State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011
    2 University of Chinese Academy of Sciences, Beijing 100049
    3 College of Grassland and Environmental Sciences, Xinjiang Agricultural University, Urumqi 830052
  • Received:2021-08-18 Accepted:2021-01-14 Online:2022-04-07 Published:2022-03-11
  • Contact: Xiaoying Rong

摘要:

评估极端干旱对温带荒漠土壤真菌群落的影响有助于进一步认识干旱导致的区域荒漠化特征。本研究利用在古尔班通古特沙漠建立的干旱三年和干旱十年样地, 分析了长期极端干旱对温带荒漠土壤真菌群落和生态网络的影响。结果显示, 干旱三年与干旱十年处理对总真菌和丰富真菌的Chao1和Shannon多样性指数均无显著性影响, 而对稀有真菌的Shannon多样性指数有显著促进作用; 干旱三年和干旱十年处理显著影响总真菌、丰富和稀有真菌的群落组成, 且极端干旱对稀有真菌群落变异的影响(ANOSIM, R = 0.378-0.595, P < 0.01)大于对丰富真菌的影响(ANOSIM, R = 0.282-0.555, P < 0.01), 表明丰富真菌具有更强的干旱抵抗力; 另外, 极端干旱显著降低了总真菌、丰富和稀有真菌的β多样性, 表明极端干旱具有生态过滤作用。分子生态网络结果显示, 干旱三年与干旱十年处理降低了荒漠土壤真菌群落网络复杂性, 表明极端干旱减弱了真菌物种间的相互作用; 相比稀有真菌, 丰富真菌具有更高的节点拓扑参数(P < 0.05), 表明丰富真菌对维持极端干旱下的真菌物种间相互作用的重要性。综上所述, 极端干旱显著改变了荒漠表层土壤真菌群落组成, 减弱了真菌物种间的相互作用; 稀有真菌敏感响应极端干旱, 有利于减缓荒漠土壤真菌群落响应的滞后性; 丰富真菌作为网络的核心菌群, 对维持极端干旱下的真菌群落稳定性以及物种间的相互作用很关键。

关键词: 古尔班通古特沙漠, 极端干旱, 丰富真菌类群, 稀有真菌类群, 分子生态网络

Abstract

Aims Extreme drought exacerbates the expansion of desert areas around the world. Microbial diversity is associated with multiple ecosystem functions in the desert. Evaluating the response of fungal communities to extreme drought is essential for our understanding of regional desertification caused by drought in a temperate desert.

Methods Based on three-year (D3) and ten-year (D10) drought plots established in the Gurbantunggut Desert, we investigated the effect of extreme drought on the diversity and ecological network of fungal communities.

Results Our results demonstrated that in both the D3 and D10 plots, the droughts had no significant influence on the Chao1 and Shannon diversity indexes of the whole and abundant fungi, while the rare fungal Shannon diversity index significantly increased. Both extreme drought treatments had a noticeable effect on community composition of whole, abundant and rare fungi, with stronger effect on rare fungi (ANOSIM, R = 0.378-0.595, P < 0.01) than that on the abundant fungi (ANOSIM, R = 0.282-0.555, P < 0.01), suggesting that abundant fungi were more resistant to drought than rare taxa. Moreover, beta-diversity of the whole, abundant, and rare fungi decreased significantly in D3 and D10 treatments, suggesting that extreme drought served as an ecological filter on fungal community assembly. Molecular ecological network analysis revealed that in both the D3 and D10 plots there was a reduced fungal network complexity, suggesting that extreme drought reduced the interactions among fungal communities. In addition, abundant fungi had higher node topological parameters (P < 0.05), indicating that abundant fungi were important for maintaining fungal species interactions under extreme drought conditions.

Conclusion Extreme drought significantly altered fungal community composition and weakened the interactions among fungal communities in a temperate desert. Furthermore, rare fungi were sensitive to extreme drought, contributing to reducing the lag in the response to fungal communities, and abundant fungi, as the core microflora in fungal networks, were crucial to sustaining the stability of fungal communities and interactions among species under extreme drought conditions.

Key words: Gurbantunggut Desert, extreme drought, abundant fungal taxa, rare fungal taxa, molecular ecological network