亚热带森林转换对土壤氮转化关键功能微生物群落的影响  

Effects of subtropical forest conversion on key functional microbial communities of soil nitrogen transformation

作　　者：刘婷 雷志刚[4] 陈述 吴小红 欧阳子都[6] 闫文德 LIU Ting;LEI Zhigang;CHEN Shu;WU Xiaohong;OUYANG Zidu;YAN Wende(College of Life Science and Technology,Central South University of Forestry and Technology,Changsha 410004,China;National Engineering Laboratory for Applied Technology of Forestry and Ecology in Southern China,Changsha 410004,China;Lutou National Station for Scientific Observation and Research of Forest Ecosystems,Yueyang 414000,China;The Third Surveying and Mapping Institute of Hunan province,Changsha 410007,China;School of Earth Systems and Sustainability,Southern Illinois University Carbondale,Illinois 62901,United States;College of Science,Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南林业科技大学,生命科学与技术学院,长沙410004 [2]南方林业生态应用技术国家工程实验室,长沙410004 [3]湖南芦头森林生态系统国家定位观测研究站,岳阳414000 [4]湖南省第三测绘院,长沙410007 [5]南伊利诺伊大学卡本代尔分校,地球系统与可持续发展学院,美国629016 [6]中南林业科技大学,理学院,长沙410004

出　　处：《生态学报》2024年第9期3636-3647,共12页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(U21A20187);湖南省教育厅科学研究项目(22B0241);长沙市自然科学基金项目(kq2208409);中南林业科技大学引进人才科研启动基金项目(ZK2023YJ001)。

摘　　要：近年来,由于林地开发和商品林建设等原因,我国亚热带地区大量天然林和次生林经皆伐改造为林分结构简单、树种单一的人工林。氮(N)素是维持森林植被生长和系统初级生产力的重要因子,土壤微生物驱动了森林土壤N转化的关键过程。然而,目前亚热带森林转换对土壤N转化微生物群落的影响仍不清晰。以湖南芦头森林生态系统国家定位观测研究站内典型次生林(CS)及由其转换而成的油茶(YC)、黄桃(HT)、杨梅(YM)和杉木(SM)四种人工林为研究对象,采用实时荧光定量PCR和高通量测序等方法,研究了各林分土壤性质、固N菌和氨氧化微生物功能基因丰度、群落特征及相互关系,旨在探讨亚热带森林转换后土壤N转化关键过程(固N和氨氧化作用)的功能微生物群落变化及驱动因素。结果表明:森林转换显著改变了土壤碳(C)、N含量,降低了土壤nifH基因丰度、固N菌和氨氧化细菌的群落α多样性,但提高了氨氧化微生物amoA基因丰度和氨氧化古菌的群落α多样性;并且,森林转换通过改变各功能微生物优势菌群(如变形菌、蓝细菌、泉古菌和奇古菌等)的相对丰度,显著影响了土壤固N菌和氨氧化微生物的群落组成;冗余分析和结构方程模型表明,土壤有机碳、全氮、铵态氮含量和pH是驱动土壤固N菌和氨氧化微生物群落变化的关键因素。森林转换后,合理的施肥方式有利于人工林土壤固N菌和氨氧化微生物的群落恢复。研究结果为转换后单一人工林土壤养分恢复、生产力的提高和可持续经营提供了科学依据。In recent years,due to the development and construction of commercial forests,a large scale of natural and secondary forests has been cleared and converted to monoculture plantations with simple stand structures in the subtropical regions of China.Nitrogen(N)is considered an important factor for maintaining the vegetation growth and primary productivity of forest systems,and soil microorganisms drive the key process of soil N transformation.However,the effects of subtropical forest conversion on microbial communities related to soil N transformation remain largely elusive.This paper aims to clarify the responses of microbial communities and their driving factors in the key processes of soil N transformation(N⁃fixation and ammonia oxidation)after subtropical forest conversion.Here,we used the real⁃time PCR and high⁃throughput sequencing technique,investigated the soil properties,function gene,community characteristics of N⁃fixing bacteria and ammonia oxidizers and their relationships in a secondary forest(CS)and four 5⁃year⁃old monoculture plantations,including Camellia oleifera(YC),Amygdalus persica(HT),Myrica rubra(YM),and Cunninghamia lanceolate(SM)in the Lutou National Station for Scientific Observation and Research of Forest Ecosystems in Hunan Province.The results indicated that forest conversion significantly changed the soil carbon(C),N contents,decreased the nifH gene abundance,theα⁃diversity of N⁃fixing bacteria and ammonia⁃oxidizing bacteria(AOB)communities,but increased the amoA gene abundances of the ammonia⁃oxidizing microorganisms,and theα⁃diversity of ammonia⁃oxidizing archaea(AOA)community.Moreover,forest conversion affected the composition of N⁃fixing bacteria and ammonia⁃oxidizers communities by altering the relative abundance of the dominant taxa,such as Proteobacteria,Cyanobacteria,Crenarchaeota and Thaumarchaeota.Lastly,redundancy analysis and structural equation modeling demonstrated that soil organic carbon(SOC),total nitrogen(TN),ammonium nitrogen(NH+4⁃N)con

关 键 词：森林转换 土壤氮转化 固氮菌 氨氧化古菌 氨氧化细菌 

分 类 号：S714.3[农业科学—林学]