青藏高原季节冻土冻融过程对土壤呼吸的影响  

Effects of Freeze-thaw Process on Soil Respiration in Seasonally Frozen Soil on the Tibetan Plateau

作　　者：聂婷 余钟波[1,2] 江鹏[1,2,3] 次旦多杰 童凯 鞠琴[1,2] NIE Ting;YU Zhongbo;JIANG Peng;CIDAN Doujie;TONG Kai;JU Qin(The National Key Laboratory of Water Disaster Prevention,Hohai University,Nanjing 210098,China;Cooperative Innovation Center for Water Safety and Hydro Science,Hohai University,Nanjing 210098,China;Middle Yarlung Zangbo River Natural Resources Observation and Research Station of Tibet Autonomous Region,Chengdu 610036,China;Linzhi Water Resources Bureau,Tibet Autonomous Region Hydrology and Water Resources Survey,Lhasa 850000,China;Key Laboratory of Environment Change and Resources Use in Beibu Gulf,Ministry of Education,Nanning Normal University,Nanning 530001,China)

机构地区：[1]河海大学水灾害防御全国重点实验室,江苏南京210098 [2]河海大学水安全与水科学协同创新中心,江苏南京210098 [3]雅鲁藏布江中游自然资源西藏自治区野外科学观测研究站,四川成都610036 [4]西藏自治区水文水资源勘测局林芝水资源分局,西藏拉萨850000 [5]南宁师范大学北部湾环境演变与资源利用教育部重点实验室,广西南宁530001

出　　处：《水文》2025年第2期1-8,共8页Journal of China Hydrology

基　　金：国家自然科学基金项目(U2240217,52179013);“一带一路”水与可持续发展科技基金资助项目(2023491511);水灾害防御全国重点实验室自主研究项目(524015252,5240152M2,5240152N2)。

摘　　要：冻融过程中的土壤温度和水分条件的变化,显著影响季节冻土的土壤呼吸动态,同时土壤呼吸释放的二氧化碳通过加剧温室效应影响气候,从而改变降水、蒸散过程等关键水文循环环节。因此,量化季节冻土的冻融过程与土壤呼吸之间的关系,对预测区域气候和水文循环的动态平衡十分关键。以澜沧江上游类乌齐县的季节冻土为研究对象,基于土壤呼吸和冻融过程连续原位测量数据,建立不同冻融阶段的土壤呼吸单因子模型,分析冻融过程中土壤温度和含水量对土壤呼吸的影响。结果表明,昼夜尺度和单次冻融过程的土壤呼吸通量均呈单峰变化,完全融化阶段的土壤呼吸贡献率约为94%;当土壤含水量大于0.09 m^(3)·m^(-3)时,土壤温度对冻融过程中的土壤呼吸影响最为显著;回归拟合中土壤呼吸与土壤温度的指数模型表现最佳,土壤呼吸的温度敏感性指标Q_(10)在融化阶段最高(43.21±4.72),完全融化阶段最低(2.71±0.17),总体随土壤含水量降低和土壤温度升高而减小。研究结果可为青藏高原暖湿化背景下的季节冻土区土壤碳排放的相关研究提供参考。Changes in soil temperature and moisture conditions during the freeze-thaw process significantly affect the dynamics of soil respiration in seasonally frozen soil,while carbon dioxide released from soil respiration influences the climate by exacerbating the greenhouse effect,thereby altering key hydrological cycle components such as precipitation and evapotranspiration processes.Therefore,quantifying the relationship between freeze-thaw process and soil respiration in seasonally frozen soil is crucial for predicting the regional climate and the dynamic balance of the hydrological cycle.In this paper,based on the continuous in situ measurements of soil respiration and freeze-thaw process in seasonally frozen soil of Leiwuqi County,in the upper reaches of the Lancang River,one-factor models of soil respiration at different freeze-thaw stages were established to analyze the effects of soil temperature and moisture on soil respiration during the freeze-thaw process.The results show that soil respiration fluxes on the diurnal scale and in a single freeze-thaw process vary unimodally,and the contribution of soil respiration in the thawed stage was about 94%.Soil temperature is the most important influence on soil respiration during freeze-thaw process when soil water content is greater than 0.09 m^(3)·m^(-3).The exponential model of soil respiration versus soil temperature in the regression fitting performs the best,the temperature sensitivity index of soil respiration(Q_(10))is highest in the thawing stage(43.21±4.72),lowest in the complete thawing stage(2.71±0.17),and generally decreases with decreasing soil moisture and increasing soil temperature.The results of the study can provide a reference for further research of soil carbon emission in the seasonally frozen soil zone under the background of warming and humidification in the Tibetan Plateau.

关 键 词：土壤呼吸 冻融过程 季节冻土 土壤温度 土壤含水量 青藏高原 

分 类 号：P593[天文地球—地球化学]