中文摘要：

为探讨放牧强度季节调控下荒漠草原地上现存量的变化趋势及放牧强度与季节的耦合作用对地上现存量影响,本研究整理2010—2014年9月蒙古高原短花针茅荒漠草原地上现存量观测数据,采用对比分析和回归建模对荒漠草原地上现存量进行了研究。结果表明：荒漠草原地上现存量在试验处理间和年度间均存在极显著性差异（P〈0.01）,且放牧处理效应大于年度间水温变化引起的生物量变化。回归建模分析显示,通过6个试验处理可建立拟合率达到99%以上的通用模型,根据通用模型可以预测27种试验处理组合的地上现存量变化;模型同时显示,春季放牧强度增加可导致草地可持续利用能力下降,且前一季节放牧强度对后一季节放牧存在明显影响,不同放牧季存在影响结果的叠加作用,导致前期的影响作用在放牧季被放大,使得草地在重牧过程后的可恢复能力降低。

英文摘要：

To discuss the variation of aboveground standing biomass of desert steppe under seasonal regulation of grazing intensity and the relationship between grazing intensity and seasonal regulation, we collected the observational data of the aboveground standing biomass in Stipa breviflora desert steppe of the Mongolian Plateau in September 2010-2014, and analyzed the standing aboveground biomass in the desert steppe using comparative analysis and regression modeling. The results showed that there were significant differences in both experimental treatments and years on the aboveground standing biomass in the desert steppe （P〈0.01）, and the grazing treatment effect was greater than the interannual biomass change caused by the variations of annual precipitation and air temperature. Regression modeling analysis showed that a general model could be used to predict the aboveground standing biomass changes of 27 experimental treatments and its fitting rate was more than 99% by 6 experimental treatments. The model also showed that the increased grazing intensity in spring could lead to decreased grassland utilization, and the grazing intensity of previous season can significantly affect the grazing of subsequent season. Different grazing seasons had additive effects, which led to an amplified influence of the previous grazing in the subsequent grazing season, and thus reduced the recoverability of grassland after heavy grazing.