滇中亚高山森林土壤细菌多样性及群落结构对N沉降的响应  

Responses of soil bacterial diversity and community structure to N sedimentation in alpine forests in central Yunnan

作　　者：毛煜民 王克勤[1,2] 宋娅丽 张晓花[1] 梁阳森 肖文贤 MAO Yumin;WANG Keqin;SONG Yali;ZHANG Xiaohua;LIANG Yangsen;XIAO Wenxian(School of Ecology and Environment,Southwest Forestry University,Kunming 650224,Yunnan,China;Yuxi Forestry Ecosystem Research Station of National Forestry and Grassland Administration,Kunming 650224,Yunnan,China)

机构地区：[1]西南林业大学生态与环境学院,云南昆明650224 [2]国家林业和草原局云南玉溪森林生态系统国家定位观测研究站,云南昆明650224

出　　处：《中南林业科技大学学报》2023年第8期125-137,共13页Journal of Central South University of Forestry & Technology

基　　金：云南省教育厅科学研究基金项目(2022Y601、2022J0510);云南省农业基础研究联合专项(202301BD070001-059);云南省自然生态监测网络项目(2022-YN-13);云南玉溪森林生态系统国家长期科研基地资助项目(2020132550)。

摘　　要：【目的】研究N沉降对不同森林类型细菌多样性及群落结构的影响,旨在为我国西南亚高山森林土壤细菌群落以及森林生态系统应对N沉降等研究提供理论基础。【方法】以亚热带高海拔季风气候区高山栎林、云南松林、华山松林和常绿阔叶林为研究对象,设定4个N施氮水平:对照(CK,0 g·m^(-2)·a^(-1))、低氮(LN,10g·m^(-2)·a^(-1))、中氮(MN,20 g·m^(-2)·a^(-1))、高氮(HN,25 g·m^(-2)·a^(-1)),测定施N18个月后土壤细菌多样性及群落结构变化特征。【结果】1)4种林分类型土壤细菌多样性存在一定差异,细菌α多样性指数表现为:常绿阔叶林>华山松林>云南松林>高山栎林;不同施N浓度会造成细菌多样性变化,即随着施N浓度增加,细菌多样性呈先下降后上升的趋势。2)不同施N处理下,土壤细菌群落优势门均由酸杆菌门(29.10%~44.46%)、变形菌门(25.22%~37.50%)、放线菌门(9.3%~12.1%)组成,其中酸杆菌门相对丰度随施N浓度上升而降低,而变形菌门则相反。3)优势属中仅罗河杆菌属、厌氧黏细菌属、出芽菌属、黏液杆菌属在不同施N浓度之间有显著差异。4)土壤细菌一级功能代谢通路包括6类,其中最主要的功能代谢(51.5%~52.2%);二级代谢通路功能基因获取41类,其中主要的二级代谢通路包括10类,碳水化合物代谢占总功能基因数最高(10.7%-~11.1%)。【结论】N沉降对土壤细菌多样性的影响具有阈值限制性;土壤细菌可通过改变生化过程来应对N沉降,以此提高对于N沉降的抵抗能力;林分类型因C源差异、立地特征等因素,为影响N沉降下土壤细菌多样性与群落结构差异的重要因素。【Objective】The purpose of this study was to explore the effects of N deposition on the bacterial diversity and community structure of different forest types,to provide a theoretical basis for the study of soil bacterial communities and forest ecosystems responding to N sedimentation in subalpine forests of southwest China.【Method】In this paper,the Quercus semicarpifolia forest,Pinus yunnanensis forest,Pinus armandii Franch.forest and evergreen broad-leaf forest in the subtropical high-altitude monsoon climate zone were studied.The treatment of four N deposition levels was set,including control check(CK,0 g·m^(-2)·a^(-1)),low nitrogen(LN,10 g·m^(-2)·a^(-1)),medium nitrogen(MN,20 g·m^(-2)·a^(-1)),and high nitrogen(HN,25 g·m^(-2)·a^(-1)).The characteristics of soil bacterial diversity and community structure changes 18 months after applying N fertilizer were determined.【Result】1)There were certain differences in the soil bacterial diversity of the four types of forest stands.It was manifested as evergreen broad-leaf forest>Pinus armandii Franch.forest>Pinus yunnanensis forest>Quercus semicarpifolia forest.Different applications of N concentrations can cause changes in bacterial diversity,that was,with the increase in the N concentration,the bacterial diversity showed a trend of first decreasing and then rising.2)Under different N application treatments,the dominant phylum of soil bacterial community was composed of Acidobacteria(29.10%to 44.46%),Proteobacteria(25.22%to 37.50%)and Actinobacteria(9.3%to 12.1%).The relative abundance of Acidobacteria decreased with the increase in the N application,while Actinobacteria was the opposite.3)Among the dominant genera,only Rhodanobacter,Anaeromyxobacter,Gemmata and Mucilaginibacter were significantly different under different N concentrations.4)The primary functional metabolic pathways of soil bacteria included six categories,of which the most important function was functional metabolism(51.5%to 52.2%).There were forty-one types of functional genes in se

关 键 词：亚高山森林 氮沉降 细菌群落结构 细菌多样性 

分 类 号：S718.5[农业科学—林学]