中国西南典型白云岩地区不同土地利用的土壤CO_(2)及δ^(13)C_(CO_(2))的变化特征  

emporal and spatial variations of soil CO_(2) and δ^(13)C_(CO_(2)) from different land uses in typical dolomite areas of Southwest China

作　　者：王小朵 周忠发[1,2] 董慧 丁圣君 龚晓欢 熊勇 苏丹[1,2] 张叶 WANG Xiaoduo;ZHOU Zhongfa;DONG Hui;DING Shengjun;GONG Xiaohuan;XIONG Yong;SU Dan;ZHANG Ye(School of Geography and Environmental Science/School of Karst Science,Guizhou Normal University,Guiyang,Guizhou 550001,China;The State Key Laboratory Incubation Base for Karst Mountain Ecology Environment of Guizhou Province,Guiyang,Guizhou 550001,China)

机构地区：[1]贵州师范大学地理与环境科学学院/喀斯特研究院,贵州贵阳550001 [2]贵州喀斯特山地生态环境国家重点实验室培育基地,贵州贵阳550001

出　　处：《中国岩溶》2024年第5期1034-1046,共13页Carsologica Sinica

基　　金：国家自然科学基金项目(42161048):岩溶洞穴系统外源酸对碳汇效应影响机制研究;贵州省科技计划项目:喀斯特地区土壤DOM对环境变化的响应机制研究(黔科合基础-ZK[2023]一般258);贵州师范大学学术新苗基金项目(黔师新苗[2022]23号)。

摘　　要：为探究典型白云岩地区不同土地利用的土壤CO_(2)及δ^(13)C_(CO_(2))的时空差异和影响因素,厘清白云岩地区土壤碳循环的机理,文章选取中国西南典型白云岩地区--双河洞国家地质公园为研究对象,对园内不同土地利用类型的土壤CO_(2)及其δ^(13)C_(CO_(2))进行为期一年的监测,并运用数理统计方法进行系统分析。结果表明:(1)不同土地利用类型土壤CO_(2)浓度表现为:耕地>灌草地>撂荒地>灌丛地>有林地>退耕还林地,土壤温度和含水量、上覆植被、有机碳和人类活动等是影响其变化的重要因素;(2)不同土地利用类型土壤δ^(13)C_(CO_(2))表现为:灌丛地>退耕还林地>耕地>灌草地>撂荒地>有林地。土壤12C和13C的扩散率、有机碳的分解转换及同位素分馏作用、植物光合作用和碳酸盐岩溶蚀等存在差异导致土壤δ^(13)C_(CO_(2))变化;(3)时间变化上,不同土地利用类型土壤CO_(2)浓度均呈现出雨季高旱季低的变化特征,土壤δ^(13)C_(CO_(2))则呈现相反的季节变化特征。土壤有机物氧化分解、微生物的代谢活动、植物根系呼吸作用及碳酸盐岩溶蚀作用是研究区土壤CO_(2)的主要来源。Shuanghedong national geopark is a prominent example of dolomite on a global scale.Soil CO_(2) in the dolomite areas is an important driving force of karstification and has great significance for the global carbon cycle.However,the mechanism of soil carbon cycle in dolomite areas has yet to be clarified.In order to investigate the spatial and temporal variations and influencing factors of soil CO_(2) and δ^(13)C_(CO_(2)) in different land uses in typical dolomite areas and to clarify the mechanism of soil carbon cycle in these areas,this study selected Shuanghedong National Geopark,a typical dolomite area in Southwest China,as the study area.Soil CO_(2) and δ^(13)C_(CO_(2)) were sampled from six typical land use types in Shuanghedong national geopark.These samples were monitored outdoors and subjected to laboratory experiments over the course of one year.Additionally,the data were systematically analyzed with mathematical and statistical methods.The study results indicate as follows,(1)Soil CO_(2) concentrations of different land use types were observed in the following order:cropland>irrigation grassland>abandoned land>scrubland>forested land>fallow land.Soil temperature and water content,overlying vegetation,organic carbon,and human activities were important factors influencing the changes of soil CO_(2) in different land use types.(2)The values of soil δ^(13)C_(CO_(2)) of different land use types were ranked as follows,scrubland>fallow land>cropland>irrigation grassland>abandoned land>forested land.Differences in diffusion rates of soil 12C and 13C,decompositional conversion of organic carbon and isotopic fractionation,plant photosynthesis and carbonate rock dissolution led to changes of soil δ^(13)C_(CO_(2)) in different land use types.(3)In terms of temporal changes,soil CO_(2) concentrations of different land use types were high in the rainy season and low in the dry season,while concentrations of soil δ^(13)C_(CO_(2)) exhibited opposite seasonal patterns,showing small values in the rainy season and la

关 键 词：土壤CO_(2) 土壤δ^(13)_(CCO_(2)) 白云岩 不同土地利用 时空变化 影响因素 土壤碳循环 

分 类 号：S154.1[农业科学—土壤学]