大气CO_(2)浓度升高对稻田CH_(4)排放及相关微生物过程影响研究进展  

Research progress on the effects of elevated atmospheric CO_2 concentration on CH_(4) emission and related microbial processes in paddy fields

作　　者：田茂辉 沈李东[2] 苏维词[3,4] TIAN Maohui;SHEN Lidong;SU Weici(Guizhou Instituteof Mountain Resources,Guiyang 550001,China;College of Ecology and Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044,China;School of Geography and Tourism,Chongqing Normal University,Shapingba 401331,Chongqing,China;Guizhou Academy of Sciences,Guiyang 550001,China)

机构地区：[1]贵州省山地资源研究所,贵阳550001 [2]南京信息工程大学生态与应用气象学院,南京210044 [3]重庆师范大学地理与旅游学院,重庆沙坪坝401331 [4]贵州科学院,贵阳550001

出　　处：《应用生态学报》2024年第8期2267-2281,共15页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(42161052);贵州省科技支撑计划项目(黔科合支撑[2022]一般200)资助

摘　　要：稻田是甲烷(CH_(4))的重要排放源之一,其对全球气候变化有着重要影响。大气CO_(2)浓度升高(e[CO_(2)])对稻田生态系统碳循环具有重要作用,阐明e[CO_(2)]对稻田CH_(4)排放及相关微生物过程的影响对稻田生态系统的固碳和减排具有重要意义。本文综述了e[CO_(2)]对稻田CH_(4)排放及碳循环相关功能微生物活性、丰度、群落组成和多样性的影响,梳理了e[CO_(2)]背景下不同微生物过程在稻田CH_(4)减排中的作用及其主要环境影响因素。总体而言,不同e[CO_(2)]平台类型、熏蒸年限、浓度梯度以及增加方式均对稻田CH_(4)排放有着一定影响。e[CO_(2)]促进了稻田CH_(4)排放,但会随着CO_(2)熏蒸年限的增加而逐渐降低,这说明稻田CH_(4)排放相关微生物对e[CO_(2)]具有一定适应性;e[CO_(2)]对稻田CH_(4)排放的促进作用呈先减弱后增强的趋势;骤增处理可能会高估稻田CH_(4)排放。e[CO_(2)]对相关微生物过程的影响主要表现为:e[CO_(2)]提高了产甲烷菌、甲烷好氧氧化菌和厌氧氧化菌活性及主要功能微生物丰度;e[CO_(2)]使甲烷氧化菌群落组成和多样性发生显著改变,但对产甲烷菌和甲烷厌氧氧化菌群落组成和多样性影响不大。最后,本文对未来相关的研究方向进行了展望:1)可综合探究e[CO_(2)]对稻田CH_(4)排放及产甲烷过程、甲烷好氧和厌氧氧化过程的影响,以更好地揭示气候变化对稻田CH_(4)排放的机理;2)应在长期条件下探究e[CO_(2)]对稻田CH_(4)排放及相关微生物过程的影响机制,结果将更为真实、准确;3)需进行多尺度(时间和空间)、多要素(CO_(2)浓度、温度、大气氮沉降和水分管理措施)以及多方法(观测、数据与模型相结合)等综合研究,以有效降低未来气候变化情景下稻田CH_(4)排放及相关微生物过程对e[CO_(2)]响应评估的不确定性。Paddy fields are recognized as significant sources of methane(CH_(4))emissions,playing a pivotal role in global climate change.Elevated atmospheric carbon dioxide(CO_(2))concentrations(e[CO_(2)])exert a profound influence on the carbon cycling of paddy fields.Understanding the effects of e[CO_(2)]on CH_(4) emissions,as well as the underlying microbial processes,is crucial for enhancing carbon sequestration and reducing emissions in paddy fields.We reviewed the impacts of e[CO_(2)]on CH_(4) emission in paddy fields,focusing on the activity,abundance,community structure,and diversity of carbon-cycling-related microbes.We also delineated the roles of various microbial processes in mitigating CH_(4) emissions under e[CO_(2)],as well as the primary environmental determinants.Overall,the type of e[CO_(2)]experimental platforms,duration of fumigation,concentration gradients,and the methods of CO_(2) enrichment all influence CH_(4) emissions from paddy fields.e[CO_(2)]initially stimulates CH_(4) emissions,which may decrease over time,indicating an adaptability of the methane-emitting microbial community to e[CO_(2)].This response exhibits a trend of initial attenuation followed by an intensification of the positive effects on CH_(4) emissions.Experiments with abrupt increase of CO_(2) concentration might overestimate CH_(4) emissions.The impact of e[CO_(2)]on microbial processes is predominantly characterized by enhanced activities and abundance of methanogens,aerobic and anaerobic methanotrophs.It significantly alters the community composition and diversity of methanotrophs,with minimal effects on methanogens and anaerobic methanotrophic communities.Finally,we outlined future research directions:1)Integrated investigations into the effects of e[CO_(2)]on CH_(4) emissions,methanogenesis,and both aerobic and anaerobic methanotrophs in paddy fields could elucidate the mechanisms underlying the impacts of climate change on CH_(4) emissions;2)Long-term studies are essential to understand the mechanisms of e[CO_(2)]on CH_(4)

关 键 词：气候变化 温室气体 产甲烷 甲烷好氧氧化 甲烷厌氧氧化 

分 类 号：S511[农业科学—作物学] S181