北热带喀斯特季节性雨林土壤细菌多样性分布格局及其影响因子  

Distribution pattern and influencing factors of soil bacterial diversity in the karst seasonal rainforest of northern tropics

作　　者：杨美雪 罗婷 钟艺倩 吴淼锐 陶旺兰 陆芳 王斌[2,3] 向悟生 唐年武[2,3] 李先琨 YANG Meixue;LUO Ting;ZHONG Yiqian;WU Miaorui;TAO Wanglan;LU Fang;WANG Bin;XIANG Wusheng;TANG Nianwu;LI Xiankun(College of Life Sciences,Guangxi Normal University,Guilin,Guangxi,China;Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain,Guangxi Institute of Botany,Chinese Academy of Sciences,Guilin,Guangxi,China;Nonggang Karst Ecosystem Observation and Research Station of Guangxi,Chongzuo,Guangxi,China)

机构地区：[1]广西师范大学生命科学学院,广西桂林 [2]广西壮族自治区中国科学院广西植物研究所,广西喀斯特植物保育与恢复生态学重点实验室,广西桂林 [3]弄岗喀斯特生态系统广西野外科学观测研究站,广西崇左

出　　处：《微生物学报》2025年第4期1358-1376,共19页Acta Microbiologica Sinica

基　　金：国家自然科学基金(32271599);广西壮族自治区科技基地和人才专项(桂科23-026-273)。

摘　　要：广西北热带喀斯特季节性雨林是我国特有的森林生态系统,然而其土壤微生物多样性及其维持机制尚不清楚。【目的】探究北热带喀斯特季节性雨林土壤细菌多样性分布特征及影响因子,为该地区土壤微生物多样性及其维持机制的解析提供参考依据。【方法】以弄岗北热带喀斯特季节性雨林15 hm2长期动态监测样地(以下简称弄岗样地)为例,基于16S rRNA基因高通量测序技术对其土壤细菌群落组成、多样性分布格局及其潜在影响因子进行分析。【结果】弄岗样地3种生境(洼地、中坡、山顶)的土壤共包含细菌操作分类单元(operational taxonomic unit,OTU)5841个,隶属于35门104纲242目373科677属1501种,主要优势细菌门为变形菌门(Proteobacteria)、放线菌门(Actinobacteriota)和酸杆菌门(Acidobacteriota)等。洼地与中坡生境的优势细菌门均为变形菌门,而山顶生境则为放线菌门。在生境水平上,土壤细菌总OTU数与特异OTU数呈洼地>中坡>山顶的规律;但在群丛水平上,尽管山顶群丛(HH)的OTU总数显著少于其他群丛,其特异OTU数量却是最多的。土壤细菌α多样性(Chao1、Sobs、Shannon、Simpson)指数在洼地与中坡生境间差异不显著,但山顶显著低于洼地与中坡生境,群丛HH也显著低于其他群丛。β多样性主坐标分析(principal co-ordinates analysis,PCoA)表明,土壤细菌群落结构在不同生境及群丛中存在明显差异。线性判别分析(linear discriminant analysis effect size,LEfSe)表明,洼地与山顶生境的标志类群较多,而中坡的差异指示种最少。相关性分析(Spearman correlation与Mantel test)及冗余分析(redundancy analysis,RDA)表明,平均海拔(average elevation,AvELE)是影响不同生境土壤细菌分布的主要因子,土壤有机碳(soilorganiccarbon,SOC)、碱解氮(alkalihydrolyzable nitrogen,AN)及速效磷(available phosphorus,AP)的影响次之。基于Tax4Fun的功能预测显示,土壤细菌群�The karst seasonal rainforest of northern tropics in Guangxi is a unique forest ecosystem in China.However,the soil microbial diversity and its maintenance mechanism remain unclear.[Objective]This study explored the distribution characteristics and influencing factors of soil bacterial diversity in a karst seasonal rainforest of northern tropics,aiming to provide a reference for analyzing soil microbial diversity and its maintenance mechanisms in this region.[Methods]Soil samples were collected from a long-term dynamic monitoring plot in the karst rainforest of northern tropics(referred to as the Nonggang plot).The composition and distribution pattern of soil bacterial community were analyzed by 16S rRNA gene amplicon sequencing,and the potential influencing factors were identified by the correlation analysis.[Results]The soil in Nonggang plot harbored a total of 5841 bacterial operational taxonomic units(OTUs),which were annotated to 1501 species belonging to 677 genera,373 families,242 orders,104 classes of 35 phyla.The dominant bacterial phyla were Proteobacteria,Actinobacteriota,and Acidobacteriota.The dominant bacterial phylum was Proteobacteria in both the depression and the slope habitats,and Actinobacteriota in the hilltop habitat.The number of total and specific bacterial OTUs displayed a pattern of depression>slope>hilltop habitats.The hilltop habitat association had the fewest total OTUs but the most specific OTUs.The soil bacterial alpha diversity indexes(Chao1,Sobs,Shannon,and Simpson)were not significantly different between the depression and slope habitats,while they were significantly lower in the hilltop habitat.Similarly,the hilltop habitat association had the lowest bacterial alpha diversity indexes than the other associations.The principal coordinate analysis(PCoA)of beta diversity showed differences in the bacterial communities among different habitats and associations.The linear discriminant analysis effect size(LEfSe)identified more differential groups in the depression and hilltop habitats

关 键 词：喀斯特季节性雨林 土壤细菌 群落多样性 生境 海拔 理化因子 

分 类 号：S714.3[农业科学—林学]