土壤微生物多样性通过共现网络复杂性表征高寒草甸生态系统多功能性  

Soil microbial richness predicts ecosystem multifunctionality through co-occurrence network complexity in alpine meadow

作　　者：张君红 王健宇 孟泽昕 何佳 董政宏 刘凯茜 陈文青 ZHANG Junhong;WANG Jianyu;MENG Zexin;HE Jia;DONG Zhenghong;LIU Kaiqian;CHEN Wenqing(College of Grassland Agriculture,Northwest A&F University,Yangling 712100,China;School of Human Settlements and Civil Engineering,Xi′an Jiaotong University,Xi′an 710049,China;China Environmental Protection Foundation,Beijing 100062,China)

机构地区：[1]西北农林科技大学草业与草原学院,杨凌712100 [2]西安交通大学人居环境与建筑工程学院,西安710049 [3]中华环境保护基金会,北京100062

出　　处：《生态学报》2022年第7期2542-2558,共17页Acta Ecologica Sinica

基　　金：西北农林科技大学“青年英才培育计划”(2452020005);国家林业和草原局科技创新青年拔尖人才专项(2020132614);国家自然科学基金青年项目(31802127)。

摘　　要：土壤微生物多样性在生态系统功能的维持方面发挥着至关重要的作用,但是土壤生物多样性与生态系统功能(Biodiversity-ecosystem function, BEF)关系仍存在争议。以往的研究多基于简单多样性指标(如物种数、香浓多样性指数等)对BEF关系进行探究,忽略了物种间复杂的相互作用在BEF关系中的重要性。以青藏高原米拉山高寒草甸为研究对象,使用Illumina MiSeq高通量测序技术测定了6个海拔高度(3755 m、3994 m、4225 m、4534 m、4900 m、5120 m)土壤细菌和真菌群落特征,分析了简单微生物多样性指标(物种数)和共现网络复杂性与生态系统多功能性(Ecosystem multifunctionality, EMF)的关系,以期进一步揭示微生物多样性与EMF的关系。共现网络分析表明,表征土壤细菌和真菌网络复杂性的节点(Node)和边(Link)沿海拔高度的升高显著下降(P<0.05)。土壤细菌和真菌的多样性和网络复杂性均沿海拔的升高显著下降(P<0.05),而且网络复杂性比相应的多样性下降明显。在未控制环境因素时,真菌和细菌的多样性和网络复杂性均与EMF显著正相关(P<0.05);其中真菌和细菌网络复杂性对EMF的解释度高于相应多样性对EMF的解释度。通过偏回归分析(Partial least squares regression, PLSR)控制年降水、年均温、黏粒含量、盐基离子和酸性离子等气候及土壤环境因子影响后,土壤细菌和真菌物种多样性与EMF的显著正相关关系变为不相关(P>0.05),而网络复杂性与EMF的显著正相关关系(P<0.05)仍然存在。利用方差分解分析(Variance partition analysis, VPA)将环境因子纳入对EMF的影响后发现,土壤微生物网络复杂性和环境因子对EMF变化的解释度可达80%,高于土壤微生物多样性与环境因子对EMF变化的解释度。结构方程模型(Structural equation model, SEM)分析进一步显示,土壤细菌多样性和真菌多样性通过促进对应共现网络的复杂性,间接对EMF产生正�Soil microbial diversity plays an indispensable role in maintaining ecosystem functions. However, the relationship of soil biodiversity-ecosystem function(BEF) remains debated. Existing studies of soil BEF relationship typically focus on the diversity metric(richness, Shannon′s diversity index), neglecting the importance of complex interactions among microbiome members in the BEF relationship. This study was based on the alpine meadows in Mount Mila of the Tibetan Autonomous Region. We used Illumina MiSeq high-throughput sequencing technology to measure the soil bacterial and fungal community characteristics in six elevations(3755 m, 3994 m, 4225 m, 4534 m, 4900 m, 5120 m) and analyzed the links between simple soil microbial diversity indicators(richness) and co-occurrence network complexity and ecosystem multifunctionality(EMF), in order to further reveal the relationship between soil microbial diversity and EMF. The co-occurrence network analysis showed that the nodes and links characterized the complexity of soil bacterial and fungal networks decreased significantly with the increase of elevation(P<0.05). Soil bacterial and fungal richness and network complexity showed a significant downward trend along the elevation gradient(P<0.05), and the decreasing trend of network complexity was more obvious than the corresponding richness. Soil bacterial and fungal network complexity and richness were significantly positively correlated with EMF(P<0.05) when the environmental factors were not controlled, and EMF was more strongly explained by fungal and bacterial network complexity than by diversity. After controlling the influence of climate and soil environmental factors such as mean annual precipitation, mean annual temperature, clay content, soil base mineral cations content, soil acid cations content by partial least squares regression(PLSR), the significant positive correlation between soil bacterial and fungal network complexity and EMF still existed(P<0.05), while the significant positive correlation between s

关 键 词：环境因子 海拔 微生物多样性 微生物共现网络 网络复杂性 生态系统多功能性 

分 类 号：S812.2[农业科学—草业科学]