黄河内蒙古段甲烷通量变化特征及甲烷功能菌群落对通量的影响  

Variation characteristics of methane fluxes in the Inner Mongolia section of the Yellow River and the effect of methane⁃functional bacterial communities on fluxes

作　　者：吴霞 王晓丽 乌音嘎[1,2] 阿如汗 虹霞 WU Xia;WANG Xiaoli;WU Yinga;A Ruhan;HONG Xia(Inner Mongolia Key Laboratory of Environmental Chemistry,Hohhot 010022,China;College of Chemistry and Environmental Sciences,Inner Mongolia Normal University,Hohhot 010022,China)

机构地区：[1]内蒙古自治区环境化学重点实验室,呼和浩特010022 [2]内蒙古师范大学化学与环境科学学院,呼和浩特010022

出　　处：《生态学报》2024年第16期7105-7118,共14页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(42167027);内蒙古自治区自然科学基金项目(2020MS04013);内蒙古自治区水环境安全协同创新中心(XTCX003);化学与环境科学学院化学重点基础学科建设项目(2023HHYC013)。

摘　　要：内陆水体被认为是甲烷(CH_(4))排放的一个重要来源,占全球CH_(4)排放总量的25%。为研究黄河内蒙古段水⁃气界面CH_(4)通量变化特征及甲烷功能菌群落对甲烷排放的影响,于2023年3月—11月采集样品,采用静态箱⁃气相色谱法探讨了黄河内蒙古段水⁃气界面CH_(4)气体通量时空变化特征并分析了其主要影响因素,利用16S rRNA基因高通量测序技术,对甲烷功能菌群落与甲烷排放通量间的关系进行了研究。研究发现:黄河内蒙古段在研究期间总体表现为大气CH_(4)的排放源,春季、夏季、秋季CH_(4)排放通量分别为(5.92±4.54)mg m^(-2)d^(-1)、(13.42±18.83)mg m^(-2)d^(-1)和(1.40±3.81)mg m^(-2)d^(-1),存在明显的季节变化,且不同采样点排放通量存在显著空间差异性。CH_(4)气体通量受多种环境因子的影响,与溶解氧(DO)呈显著负相关(P<0.05),与溶解有机碳(DOC)和铵态氮(NH_(4)^(+)⁃N)呈显著正相关(P<0.01和P=0.05)。研究区产甲烷菌优势菌群为Methanosarcina(甲烷八叠球菌属)和Methanobacterium(甲烷杆菌属),甲烷氧化菌优势菌群为Methylocystis(甲基孢囊菌属)和Methylobacter(甲基杆菌属);不同样本中甲烷功能菌群落多样性和丰富度存在显著差异,对产甲烷菌影响最大的环境因子是总碳(TC)(r=0.8792),对甲烷氧化菌影响最大的环境因子是NH_(4)^(+)⁃N(r=0.7190);在产甲烷菌群落中,Methanobacterium(甲烷杆菌属)和未分类菌属unclassified_k_norank_d_Archaea对CH_(4)排放影响最大,这类细菌会促进甲烷排放;在甲烷氧化菌群落中,未识别的甲烷氧化菌norank_d_Bacteria对CH_(4)氧化影响最大,这类细菌会促进甲烷氧化,从而减少水⁃气界面甲烷排放。本研究可为我国河流温室气体排放量的估算以及排放机制提供数据支持。Inland waters are considered to be a significant source of methane(CH_(4))emissions,accounting for 25%of total global CH_(4)emissions.This study was conducted to analyze the changing characteristics of CH_(4)fluxes at the water⁃gas interface and the influence of methane⁃functional bacterial communities on methane emissions in the Inner Mongolia section of the Yellow River.Samples were collected from March to November 2023,and the static box⁃gas chromatography was used to explore the spatio⁃temporal characteristics of CH_(4)fluxes at the water⁃gas interface and analyse its main influencing factors.Additionally,high⁃throughput sequencing techniques of the 16S rRNA gene were used to investigate the relationship between methane⁃functional bacterial communities and methane emissions.It was found that the Inner Mongolia section of the Yellow River generally behaved as a source of atmospheric CH_(4)emissions during the study period,and its CH_(4)emission fluxes were(5.92±4.54)mg m^(-2)d^(-1),(13.42±18.83)mg m^(-2)d^(-1),and(1.40±3.81)mg m^(-2)d^(-1)in spring,summer,and autumn,respectively,with significant seasonal variations and significant spatial variability of the CH_(4)emission fluxes at different sampling points.CH_(4)gas fluxes were influenced by various environmental factors,and were significantly negatively correlated with dissolved oxygen(DO)(P<0.05),and significantly positively correlated with dissolved organic carbon(DOC)and ammonium nitrogen(NH_(4)^(+)⁃N)(P<0.01 and P=0.05).The study area showed Methanosarcina and Methanobacterium as the dominant groups of methanogenic bacteria,while Methylocystis and Methylobacter were the dominant groups of methane⁃oxidizing bacteria.There were significant differences in the diversity and abundance of methane⁃functional bacteria in the different samples,with the environmental factor that had the greatest effect on methanogenic bacteria being total carbon(TC)(r=0.8792)and the environmental factor that had the greatest effect on methane⁃oxidizing bac

关 键 词：黄河内蒙古段 CH_(4)通量 影响因素 甲烷功能菌 

分 类 号：X143[环境科学与工程—环境科学] X16