中国土壤甲烷吸收时空格局及其驱动因素  

Estimating the spatiotemporal patterns and the key drivers of methane uptake in upland of China

作　　者：薛良琛 宋翰雄 吴晓丽 蒋学庆 陈槐[4] 彭长辉[2] 朱求安 XUE Liangchen;SONG Hanxiong;WU Xiaoli;JIANG Xueqing;CHEN Huai;PENG Changhui;ZHU Qiuan(College of Geography and Remote Sensing,Hohai University,Nanjing 211000,China;Department of Biology Sciences,Institute of Environment Sciences,University of Quebec at Montreal,Montreal C3H3P8,Canada;College of Hydrology and Water Resources,Hohai University,Nanjing 210009,China;Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610041,China)

机构地区：[1]河海大学地理与遥感学院,南京211000 [2]魁北克大学蒙特利尔分校环境科学研究所,蒙特利尔C3H3P8 [3]河海大学水文水资源学院,南京210009 [4]中国科学院成都生物研究所,成都610041

出　　处：《生态学报》2025年第5期2104-2121,共18页Acta Ecologica Sinica

基　　金：国家重点研发计划项目(2024YFF0808700);第二次青藏高原科学考察研究项目(2019QZKK0304⁃2)。

摘　　要：土壤中甲烷氧化菌驱动的甲烷氧化过程是大气甲烷汇的重要途径,准确量化土壤甲烷的吸收对全球及区域甲烷收支评估具有重要意义。研究基于实测数据对土壤甲烷扩散⁃反应模型(R99)关键过程进行改进,利用该改进模型对我国1990—2020年不同生态系统土壤甲烷吸收进行了模拟计算,并解析其时空格局关键驱动因子。结果表明:(1)1990年至2020年全国年均土壤甲烷吸收总量约为(2.95±0.09)Tg CH_(4)/a,裸地、耕地、森林、草地和灌丛生态系统土壤甲烷吸收量均值分别为0.53、0.43、0.79、1.00、0.20 Tg CH_(4)/a,且各生态系统土壤甲烷吸收量均呈现出夏季高冬季低的季节性特征。(2)1990年至2020年间全国土壤甲烷年吸收速率南方呈现增长的趋势,北方呈现降低的趋势,全国总体上呈上升趋势,空间上南方土壤甲烷吸收速率高于北方。(3)土壤甲烷吸收速率的空间差异主要受温度、降水、潜在蒸散量和土壤含水量的影响;南方地区土壤甲烷吸收速率的增加主要受温度和潜在蒸散量增加的影响,北方地区土壤甲烷吸收速率的降低主要受降雨量和土壤含水量减少的影响。其中,青藏高原地区受土壤含水量增加和潜在蒸散量减少的影响,土壤甲烷吸收速率呈现显著增加趋势。(4)不同生态系统土壤甲烷吸收速率的主要影响因子不同,草地和裸地主要受土壤含水量影响;森林和灌丛主要受温度影响,耕地主要受耕作强度的影响。研究对我国土壤甲烷吸收及其驱动因素进行了定量评估,可以为我国甲烷收支计算提供数据与方法支撑。The methane oxidation process,driven by soil methanotrophic bacteria,plays a critical role as a sink for atmospheric methane.Accurately quantifying soil methane uptake is therefore essential for understanding global and regional methane budgets.This study enhances the soil methane uptake diffusion⁃reaction model(R99)by incorporating empirical data and applies the modified model to simulate methane uptake across various Chinese ecosystems from 1990 to 2020,identifying key drivers of spatiotemporal variations.The results showed that:(1)From 1990 to 2020,the average annual national soil methane uptake was approximately 2.86-3.04 Tg CH_(4)/a.Mean uptake rates for bare land,cropland,forest,grassland,and shrubland ecosystems were 0.53,0.43,0.79,1.00,and 0.20 Tg CH_(4)/a,respectively,all exhibiting seasonal patterns with higher uptake in summer and lower uptake in winter.(2)Over the same period,annual soil methane uptake in southern China showed an increasing trend,while northern China experienced a decline.Overall,there was a national upward trend,with southern uptake rates exceeding those in the north.(3)Spatial differences in uptake rates were primarily influenced by temperature,precipitation,potential evapotranspiration,and soil moisture.In southern regions,rising temperatures and potential evapotranspiration were the main drivers of increased uptake,while in northern regions,reduced rainfall and soil moisture led to decreased uptake.Notably,in the Tibetan Plateau,significant increases in soil methane uptake were linked to higher soil moisture and reduced potential evapotranspiration.(4)The main factors driving uptake rates varied by ecosystem.Grasslands and bare lands were primarily influenced by soil moisture,forests and shrublands by temperature,and croplands by tillage intensity.This study provides a comprehensive assessment of soil methane uptake and its driving factors in China,offering valuable insights and methodological frameworks for national methane budget calculations.

关 键 词：温室气体 土壤甲烷吸收 气候变化 影响因子 

分 类 号：S15[农业科学—土壤学]