中文摘要：

利用动态密闭气室红外CO2分析法测定了放牧、封育两种管理方式和坡度、坡向两种不同地形草地的土壤呼吸速率。研究结果显示，在同一地形条件下，封育草地土壤呼吸速率均大于放牧草地，说明放牧可以抑制草地土壤碳的排放。管理方式和坡度相同，东北坡向草地土壤呼吸速率大于西南坡向草地，放牧草地增幅大于封育草地。管理方式和坡向相同，土壤呼吸速率随坡度的增大而减小。同一管理方式下，土壤呼吸速率与地下生物量呈现抛物线变化（P〈0．01），当地下生物量超过某一值时，土壤呼吸速率增幅减缓甚至下降。土壤温度与土壤呼吸速率极显著的指数关系（P〈0．01），封育草地土壤呼吸基础值大于放牧草地，但放牧草地较封育草地具较大的Q10值，说明放牧草地土壤呼吸对温度变化的响应更为敏感。坡度、坡向和管理方式是影响土壤呼吸重要的3个因素，三者对土壤呼吸影响的大小次序依次为：坡度〉管理方式〉坡向。

英文摘要：

Soil respiration rate of grassland under different management and topography was measured by closed chamber infrared CO2 gas analyzer. Research result showed, under same topography, soil respiration rate of excluded lands was higher than grazing lands. It indicated that grazing can restrain soil carbon release. Under same management and slope, soil respiration of shady grasslands was higher than sunny grasslands, and increased extent of grazing lands was higher than excluded lands. Under same management and aspect, soil respiration rate decreased as grasslands slope increased. Under same management, there was a parabola relationship between soil respiration rate and underground biomass （P〈0.01）.The increased extent of soil respiration will be depressed, or even decrease when underground biomass exceed a certain value. There was an extremely significant exponential relationship between soil respiration rate and soil temperature （P〈0.01）, the basal value of respiration of excluded lands was higher than grazing lands, but QIO of grazing lands was higher than excluded lands, which indicating that soil respiration of grazing lands were more sensitive to soil temperature. Slope, aspect and respiration of grassland, and the order of influencing effect management were three important influencing factors to soil was slope〉management〉aspect.