Extreme drought with seasonal timing consistently promotes CH_(4) uptake through inconsistent pathways in a temperate grassland, China  

作　　者：ZHANG Wenwen PAN Yue WEN Fuqi FU Juanjuan HAO Yanbin HU Tianming YANG Peizhi 

机构地区：[1]College of Grassland Agriculture,Northwest A&F University,Yangling 712100,China [2]Binzhou Institute of Technology,Weiqiao-UCAS(University of Chinese Academy of Sciences)Science and Technology Park,Binzhou 256606,China [3]College of Life Sciences,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Arid Land》2024年第6期768-778,共11页干旱区科学（英文版）

基　　金：This study was funded by the National Natural Science Foundation of China(42041005,U20A2050,U21A20240);the Weiqiao-UCAS(University of Chinese Academy of Sciences)Special Projects on Low-Carbon Technology Development(GYY-DTFZ-2022-006);the Fundamental Research Funds for the Central Universities(E1E40607).

摘　　要：Methane(CH_(4))is a potent greenhouse gas that has a substantial impact on global warming due to its substantial influence on the greenhouse effect.Increasing extreme precipitation events,such as drought,attributable to global warming that caused by greenhouse gases,exert a profound impact on the intricate biological processes associated with CH_(4) uptake.Notably,the timing of extreme drought occurrence emerges as a pivotal factor influencing CH_(4) uptake,even when the degree of drought remains constant.However,it is still unclear how the growing season regulates the response of CH_(4) uptake to extreme drought.In an effort to bridge this knowledge gap,we conducted a field manipulative experiment to evaluate the impact of extreme drought on CH_(4) uptake during early,middle,and late growing stages in a temperate steppe of Inner Mongolia Autonomous Region,China.The result showed that all extreme drought consistently exerted positive effects on CH_(4) uptake regardless of seasonal timing.However,the magnitude of this effect varied depending on the timing of season,as evidenced by a stronger effect in early growing stage than in middle and late growing stages.Besides,the pathways of CH_(4) uptake were different from seasonal timing.Extreme drought affected soil physical-chemical properties and aboveground biomass(AGB),consequently leading to changes in CH_(4) uptake.The structural equation model showed that drought both in the early and middle growing stages enhanced CH_(4) uptake due to reduced soil water content(SWC),leading to a decrease in NO_(3)–-N and an increase in pmoA abundance.However,drought in late growing stage primarily enhanced CH_(4) uptake only by decreasing SWC.Our results suggested that seasonal timing significantly contributed to regulate the impacts of extreme drought pathways and magnitudes on CH_(4) uptake.The findings can provide substantial implications for understanding how extreme droughts affect CH_(4) uptake and improve the prediction of potential ecological consequence under future

关 键 词：extreme climate greenhouse gas METHANE METHANOTROPHS soil inorganic nitrogen 

分 类 号：P426.616[天文地球—大气科学及气象学] X16[环境科学与工程—环境科学] S812.1[农业科学—草业科学]