[目的]研究土壤呼吸对气候变暖和干旱的响应，阐明全球气候变化与土壤碳排放之间的反馈关系。[方法]采用红外辐射增温和林内穿透雨减少技术模拟气候变暖和干旱，通过LI-8100土壤CO2通量测定系统对生长季土壤呼吸速率进行观测，分析了干旱年不同处理（对照、增温＋减雨、增温、减雨）对土壤呼吸速率的影响。[结果]显示：生长季，以上4种处理的土壤呼吸速率分别为1．78、1．84、2．02和2．01μmol·m－2·s－1，5 cm土壤温度和土壤湿度分别可以解释土壤呼吸速率变异的68．2％87．5％和51．0％66．6％。干旱期，以上4种处理的土壤呼吸速率均低于生长季，增温处理降低了土壤呼吸速率与土壤温度的相关性，但增加了土壤呼吸速率与土壤湿度的相关性。[结论]干旱年内，土壤温度和湿度是影响该区土壤呼吸速率的主要环境因子，干旱期增温处理引起土壤湿度对土壤呼吸的限制作用削弱了气候变暖与土壤碳排放之间的正反馈作用。%Objective]To explore the response of soil respiration to climate warming and drought and address the feedbacks between climate change and soil carbon flux.[Method]Infrared radiation heater and throughfall exclu-sion were conducted to simulate warming and drought in Warm-temperate oak (Quercus aliena var.acuteserrata) forest soil.The soil respiration was measured in drought year to analyze the effect of the Control,Warming +Drought,and Warming and Drought treatments on soil respiration in growing season by using LI-8100 system.[Re-sult]The result showed that:the soil respiration of 4 treatments were 1 .78 μmol CO2 m-2 s-1 ,1 .84 μmol CO2 m-2 s-1,2.02 μmol CO2m-2s-1and 2.01 μmol CO2m-2s-1,the soil temperature and soil moisture respectively ex-plained 68.2% 87.5% and 51.0% 66.6% of the temporal variation of soil respiration.The soil respiration in drought season was lower than that in growing season.The correlation coefficient (soil respiration vs.soil tempera-ture)decreased in warming treatment in drought season,but increased in the relationship of soil respiration and soil moisture.[Conclusion]Soil temperature and moisture are the main factors in regulating soil respiration in drought year,and the limited effect of soil moisture to soil respiration,which is induced by warming treatment,will mitigate the positive feedbacks between soil carbon flux and climate warming in drought season.
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