Abstract: Under the dual pressure of natural withering and continuous grazing by livestock,the above ground biomass of winter and spring grasses continues to be decreased,making this period become a high incidence and recurrence period of ecological damage and livestock disasters. Therefore,this study utilized Landsat satellite imagery from the Ruoergai region and established an optimal estimation model for winter grass biomass based on the Dead grass vegetation index (DGVI). The validation R² of the model reached 0.791 1. Based on this,a spatio-temporal dynamic monitoring and evaluation method for the forage-livestock balance in winter was proposed,and the grassland stock and overload status in different months of winter in the Ruoergai area were calculated. The overloading rate in this area rapidly increases from November to January in the early winter period and in most areas. It reaches an overloaded state and remains basically stable from January to February of the following year. The dynamic estimation method of winter forage-livestock balance based on DGVI has higher accuracy and stronger application ability than the estimation of winter forage-livestock balance using green vegetation index. The research results provide a feasible application technology and new ideas for the spatio-temporal dynamic monitoring and evaluation of winter forage-livestock balance during the dry season.

Key words: Biomass, Forage-livestock balance, Ruoergai region, Dead grass vegetation index

摘要： 冬春季牧草在自然枯黄衰减与牲畜不断采食的双重压力下，地上生物量持续消耗减少，使这一时期成为生态破坏与畜牧业灾害的高发与重发期。因此，本研究利用若尔盖地区Landsat卫星影像，基于枯草植被指数(Dead grass vegetation index，DGVI)，建立了冬季牧草生物量的最优估算模型，该模型的验证R²达到0.791 1，并在此基础上，提出了一种针对冬季枯草的草畜平衡时空动态监测与评估方法，计算了若尔盖地区的冬季不同月份草地牧草存量及其超载状况。该区域超载率在冬季前期的11月—次年1月迅速增加，次年1月—2月，大部地区达到超载状态保持基本稳定。基于DGVI的冬季草畜平衡动态估算方法，具有比利用绿色植被指数估算的冬季草畜平衡更高的准确性和更强的应用能力，研究成果可为冬季枯草期草畜平衡时空动态监测与评估提供一种可行的应用技术与新思路。

关键词: 生物量, 草畜平衡, 若尔盖地区, 枯草指数