中文摘要：

【目的】从碳平衡的角度为确定荒漠草原合理的放牧管理方式提供依据。【方法】采用野外调查法测定生物量季节动态，密闭气室法测定土壤呼吸动态。【结果】（1）相较于自由放牧，划区轮牧能保持较高的凋落物量、家畜采食量以及地下生物量，在恢复地上植被方面无明显差别，禁牧保持较高的地上生物量、凋落物量及地下生物量；（2）随着放牧的进行和季节水热条件的变化，土壤呼吸呈现不同的变化趋势，自由放牧在干旱季节产生较小的土壤呼吸；（3）生长季内划区轮牧、自由放牧和围栏禁牧下的荒漠草原净生态系统生产力分别为413．78、401．45和416．80gC·m^-2·a^-1.【结论】短花针茅荒漠草原生态系统碳收支表现为碳汇，不同放牧制度对碳收支影响较小，相对而言，划区轮牧较自由放牧有微弱的碳积累优势。

英文摘要：

[Objective] Taking Stipa breviflora desert steppe in Inner Mongolia as the research object, carbon input, carbon output and carbon balance features in plots that affected by fencing, rotational grazing and continuous grazing for ten years （1999-2009） were determined. [Method] Using field investigation and enclosed chamber method （IRGA）, the dynamics ofbiomass and soil respiration rate were determined in Stipa breviflora desert steppe. The effects of grazing systems on carbon input, carbon output and carbon balance was studied in this paper. [Result] Compared with continuous grazing, the litter fall, livestock feed intake and below-ground biomass were increased by rotational grazing, while no significant difference the community above-ground biomass was found in between continuous grazing and rotational grazing. Litter fall, above ground and below ground biomass were increased by non-grazing. Compared with continuous grazing, rotational grazing and non-grazing increased the soil respiration rate in dry months. Stipa breviflora desert steppe emerged to be carbon sinks under different grazing systems, and the net ecosystem production was, respectively, 413.78, 401.45, and 416.80 gC·m^-2·a^-1 [Conclusion] There was little difference between different grazing systems, and carbon sinks decreased in turn from non-grazing, rotational grazing to continuous grazing.