The community productivity , structure and succession are significantly influenced by global climate changes . this study focused on soil respiration rate of stipa baicalensis grassland by using dynamic infrared gas absorbed method . we analyzed diurnal pattern of soil respiration rate and the influences of surface soil temperature and water content for this parameter , then compared the differences between day and night soil respiration rates , and explored the correlations between aboveground and underground biomass with the soil respiration 温带的半干旱、半湿润区草甸草原属于过渡气候影响下形成的植被类型，对环境气候条件变化十分敏感，为了揭示半干旱、半湿润区草甸草原生态系统土壤碳素释放规律及其对主要环境因子的响应，本研究采用动态室红外气体吸收法测定松嫩草甸草原典型群落? ?贝加尔针茅群落土壤呼吸速率，分析了土壤呼吸速率日变化规律及表层土壤温度和含水量对土壤呼吸速率日变化的影响，比较了土壤呼吸速率的昼夜差异，探讨了地上生物量和地下生物量与土壤呼吸速率之间的相关关系。
