荒漠草原土壤细菌和真菌群落对降水变化的响应  

Responses of soil bacterial and fungal communities to altered precipitation in a desert steppe

作　　者：郭蓉 吴旭东 王占军[3] 蒋齐[3] 俞鸿千[3] 贺婧[1,2] 刘文娟 马琨[1,2] GUO Rong;WU Xudong;WANG Zhanjun;JIANG Qi;YU Hongqian;HE Jing;LIU Wenjuan;MA Kun(Cultivation Base of State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China,Ningxia University,Yinchuan 750021,China;Ministry of Education Key Laboratory for Restoration and Reconstruction of Degraded Ecosystems in Northwest China,Ningxia University,Yinchuan 750021,China;Institute of Forest and Grassland Ecology,Ningxia Academy of Agriculture and Forestry Sciences,Yinchuan 750021,China)

机构地区：[1]宁夏大学西北土地退化与生态恢复国家重点实验室培育基地,银川750021 [2]宁夏大学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

出　　处：《应用生态学报》2023年第6期1500-1508,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31660132);宁夏干旱半干旱区林草资源保育与生态生产功能提升关键技术研究与示范项目(NGSB-2021-14)资助。

摘　　要：为揭示荒漠草原土壤细菌、真菌群落对降水变化的响应机制,利用人工控制的方法,采用单因素完全随机设计,设自然降水(T_(0))、自然降水减少50%(T_(1))、自然降水减少25%(T_(2))、自然降水增加25%(T_(3))、自然降水增加50%(T4)5个处理,通过Illumina高通量测序和生物信息学分析,研究了不同降水增、减强度对荒漠草原土壤细菌和真菌群落的影响以及植物群落、土壤理化性状和微生物群落三者间的相互关系。结果表明:在荒漠草原的5个降水量下,T4处理的土壤细菌、真菌群落丰富度指数均高于其他处理,与T_(0)处理间差异显著;细菌优势类群中绿弯菌门和真菌稀有类群的壶菌门相对丰度对降水变化敏感。冗余分析表明,环境因子能分别解释土壤细菌和真菌群落总变异的92.8%和87.4%。降水和土壤pH是影响细菌多样性和群落组成的主要环境因子,降水一方面对细菌多样性及群落组成产生极显著的直接正效应,另一方面通过影响土壤水分改变pH,进而对细菌多样性和群落组成产生显著的间接影响。植物群落生物量和丰富度及土壤pH是影响真菌多样性和群落组成的主要环境因子,降水对土壤真菌群落变化未产生直接效应,但其能通过影响植物群落生物量、土壤pH对真菌群落产生显著的间接效应。荒漠草原土壤细菌和真菌群落对降水变化表现出不同的响应机制。To investigate the response mechanisms of soil bacterial and fungal communities to the changes of precipitation in a desert steppe of Ningxia,we conducted a three-year precipitation control experiment following completely randomized design.There were five treatments,natural precipitation(T_(0)),50%less in precipitation(T_(1)),25%less in precipitation(T_(2)),25%more in precipitation(T_(3))and 50%more in precipitation(T4).By using Illumina high-throughput sequencing and bioinformatics analysis,we investigated the effects of increased and decreased precipitation on soil bacterial and fungal communities,and examined the correlations between soil physicochemical properties,plant communities and soil bacterial and fungal communities.The result showed that the richness of soil bacteria and fungi was highest in the T4 treatment.In addition,the relative abundance of Chloroflexi,the predominant phyla of soil bacteria was more sensitive to precipitation change.However,the relative abundance of only Ascomycota,a rare fungal taxon,responded to precipitation changes.Results of redundancy analysis showed that the first two axes accounted for 92.8%and 87.4%of the total variance for soil bacterial and fungal community composition,respectively.Precipitation and soil pH were the most important environmental factors driving changes in soil bacterial diversity and community composition.On the one hand,precipitation had a direct positive effect on bacterial diversity and community composition.On the other hand,precipitation changed pH by affecting soil moisture,which in turn had a significant indirect effect on bacterial diversity and community composition.Plant community biomass,plant species richness,and soil pH were the most influential environmental factors affecting fungal diversity and community composition.Precipitation had no direct effect on soil fungal community,but had a significant indirect effect by changing plant community richness and soil pH.The response mechanisms of bacterial and fungal communities in soil differed s

关 键 词：降水变化 细菌群落 真菌群落 丰富度 多样性 高通量测序 结构方程模型 

分 类 号：S812.2[农业科学—草业科学]