径级差异驱动辽东栎根系菌根真菌群落嵌套分布格局  

Diameter of Quercus wutaishanica Shapes the Nestedness of the Root Mycorrhizal Fungal Assemblages

作　　者：林力涛 卢德亮 张霜 马克明[1,4] LIN Litao;LU Deliang;ZHANG Shuang;MA Keming(State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Center for Ecological Civilization Research,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院生态环境研究中心,城市与区域生态国家重点实验室,北京100085 [2]中国环境科学研究院生态文明理论研究中心,北京100012 [3]中国科学院沈阳应用生态研究所,辽宁沈阳110016 [4]中国科学院大学,北京100049

出　　处：《环境科学研究》2024年第10期2148-2158,共11页Research of Environmental Sciences

基　　金：国家自然科学基金项目(No.31470481,42271273)。

摘　　要：嵌套理论反映局域集合群落物种的扩散迁移特征,菌根真菌作为维管束植物重要的共生对象,明晰其迁移扩散特征有助于提升生境破碎背景下微生物资源的保护和利用,为生物多样性保护政策的制定提供依据。本文选取东灵山辽东栎林10个海拔高度不同的山体半阳坡组成研究系统,测定坡面辽东栎根系外生菌根真菌群落并调查坡面植物属性,使用坡面植物属性表征树岛特征,使用真菌菌门属性特征表征菌根真菌扩散能力,使用重叠嵌套指数(NODF)和零模型检验确定菌根真菌群落嵌套水平及嵌套显著性,探究了基于辽东栎树岛的菌根真菌群落是否呈嵌套分布及驱动因素。结果表明:①辽东栎树岛的菌根真菌群落呈显著嵌套分布格局(P<0.05),重叠嵌套指数(57.35)高于完全随机零模型和列限定零模型(物种多度限定)。②锤舌菌纲、伞菌纲和座囊菌纲等真菌菌纲分别占群落相对多度的41.46%、29.31%和16.37%,多度较高的锤舌菌纲的生态位宽度显著高于其他菌纲(P<0.05),即其树岛分布范围最广。③调整树岛属性顺序后,基于土壤温度、生境异质性集合群落的NODF值显著高于完全随机零模型(P<0.05),表明土壤温度、生境异质性主要通过驱动种群多度方式来影响菌根真菌群落分布;基于胸径集群群落的NODF值显著高于列限定零模型(P<0.05),表明植株径级差异可显著影响菌根真菌的迁移扩散路径。研究发现,菌根真菌迁移扩散过程受辽东栎径级的影响,粗径级植株可通过能源供给招募更多菌根真菌成为菌根真菌群落中的迁移扩散源,驱动形成较高的嵌套性水平和群落稳定性,因此森林经营中应适当加强对粗径级林木的保护利用。Nestedness theory reflects the patterns of species dispersal and migration within the metacommunities.Mycorrhizal fungi are vital symbionts of vascular plants and show significant distance-decay patterns in community composition and fungal spores,i.e.,dispersion-limited.A comprehensive understanding of the migration and dispersion characteristics of mycorrhizal fungi will help to protect and utilize microbial resources in fragmented habitats,which,in turn,serve as a foundation for the development of biodiversity conservation policies.Using the altitude gradient of the oak forest in Dongling Mountains that is comprised of ten semi-sunny slopes with different altitudes,we investigated the ectomycorrhizal fungal communities in the roots of Quercus wutaishanica tree islands and plant properties on these semi-sunny slopes.We used plant properties on the slope to characterize the properties of the tree islands and used fungal phylum to characterize the diffusion level of ectomycorrhizal fungi.We employed the nestedness metric based on the overlapping and decreasing fill index(NODF)and null model tests to determine the nestedness values and the significance of mycorrhizal fungal assemblages compared with random conditions.The objective of this study was to determine whether ectomycorrhizal fungal assemblages associated with Q.wutaishanica tree islands exhibit a nested pattern and to identify the underlying driving factors.The results showed that:(1)The NODF of the fungal assemblages(57.35)of the Quercus wutaishanica tree islands was higher than that of equiprobable columnsequiprobable rows(EE)nulls and fixed columns-equiprobable rows(FE)nulls(fungal population fixed)(P<0.05).(2)The Leotiomycetes,Agaricomycetes,and Dothideomycetes were the dominant classes of mycorrhizal fungi,accounting for 41.46%,29.31% and 16.37% of the community abundance,respectively.The Leotiomycetes,which has the highest relative abundance,occupied significantly higher niche width than other classes(P<0.05),i.e.,a higher tree island range.(3)When

关 键 词：集合群落 菌根真菌 嵌套性 胸径 栎林 

分 类 号：X176[环境科学与工程—环境科学]