中文摘要：

对科尔沁沙地固定、半固定和流动沙丘土壤呼吸的日进程、季节变化及其环境因素进行了测定分析。结果表明：1）土壤呼吸速率与植物群落生物量、土壤有机碳、全氮及粘粉粒含量之间存在显著的正相关关系;固定沙丘日平均土壤呼吸速率分别是半固定和流动沙丘的1.18和2.02倍。2）从固定、半固定到流动沙丘,土壤温度及近地表空气温度呈现增加的趋势,土壤含水量呈现递减的趋势。3）指数模型能够较好地揭示不同生境土壤呼吸对温度变化的响应;日进程上各生境土壤呼吸速率与温度之间的相关程度依次为：地表气温〉5 cm土壤温度〉大气温度〉10 cm土壤温度〉15 cm土壤温度;季节尺度上土壤呼吸受温度与水分的共同主导,但温度的作用大于水分。

英文摘要：

The daily and seasonal variations of soil respiration and its environmental factors were measured in different habitats（fixed,semi-fixed and moving sand dune） in Horqin sandy land.Results showed that：（1） Soil respiration rate has a significantly positive relationship with plant biomass,soil organic carbon,total nitrogen and silt＋clay content.The mean soil respiration rate in fixed sand dune during the study period is 1.18 and 2.02 times of that in semi-fixed and moving sand dune,respectively.（2） Soil temperature and surface air temperature show an increment from fixed,semi-fixed to moving sand dune,while soil water contents show a decrement.（3）The relationships between soil respiration rate and temperature for the different sandy habitats can be described by exponential equations significantly.The temperature sensibility of soil respiration decreases as follows： surface air temperature 〉5cm soil temperature 〉air temperature 〉10 cm soil temperature 〉15 cm soil temperature.Both temperature and water content control seasonal variation of CO2 efflux,but the function of temperature is greater than water content.