草原超载过牧是造成我国草原大面积退化、沙化的主要原因之一,草畜平衡监测、评价和管理是实现我国草原植被恢复和重建的关键,也是研究的热点和难点。本文采用遥感和地面调查相结合的方法从宏观上监测和评价了农业部认定的264个牧区和半牧区县的草畜平衡状况,主要结论如下:(1)2008年监测区平均草畜平衡指数为33.58%,总体处于超载状态;(2)120个牧区县草畜平衡指数为27.37%,144个半牧业县为42.07%,半牧区县是我国实行草畜平衡管理的重点和难点;(3)六大牧区中牧区县2008年超载程度排序为:甘肃〉四川〉新疆〉青海〉西藏〉内蒙古,半牧区县超载程度排序为青海〉西藏〉内蒙古〉新疆〉四川〉甘肃。本文所得结论可为我国草原资源管理和保护提供参考价值和借鉴意义。
Grassland overgrazing is one of the main causes of grassland degradation and desertification in China. Grassland-livestock balance monitoring, evaluation and management are the keys for grassland vegetation recovery and reconstruction. Using remote sensing, ground observations, and field survey, we discuss the grassland-livestock balance of the 264 pastoral counties and semi-pastoral counties identified by the Ministry of Agriculture in the macroscopic view. The main results are as follows. (1) The average index of grassland-livestock balance was 33.58% in 264 pastoral counties and semi-pastoral counties in 2008, indicating that the grassland was overgrazed in general. (2) The index of grassland- livestock balance of 120 pastoral counties and 144 semi-pastoral counties were 27.37% and 42.07% respectively. The extent of overgrazing in pastoral areas was lower than that in semi-pastoral, so it was difficult to reduce intensity of grazing and recover grassland vegetation in pastoral than in semi-pastoral. It was the major concern of grassland-livestock balance task. (3) In the six pastoral areas, from big to small permutation order of overgrazing level for pastoral counties was Gansu, Sichuan, Xinjiang, Qinghai, Tibet, Inner Mongolia, and the order for semi-pastoral was Qinghai, Tibet, Inner Mongolia, Xinjiang, Sichuan and Gansu in 2008. Conclusions may provide reference for the management and protection of grassland resources in China.