草地放牧适宜度理论及牧场管理策略

SUITABILITY-DEGREE OF GRASSLAND GRAZING AND STRATEGIES FOR PASTURE MANAGEMENT

针对当前载畜量和放牧率较为模糊甚至混乱的认识 ,该文综述了载畜量及其相关术语的概念 ,论证了载畜量与放牧率的区别与联系 ,概括了放牧适宜度理论。主要结论为 :载畜量是特定时期内一定面积的草地能够放牧的家畜数量的理论值 ,而放牧率则是特定时期内一定草地面积上实际放牧的家畜数量 ;载畜量是放牧率的额定标准 (上限 ) ,当放牧率大于载畜量 (超载 )时 ,出现草地退化现象 ;放牧适宜度是最大经济收益下 ,维系草地 (植物和动物 )持续生产的最大放牧利用强度 (即经济最佳放牧率 )。

It is no doubt that to identify the suitable carrying capacity is important in the sustainable utilization of grassland. As the confusion exists in properly understanding the relationship between carrying capacity and stocking rate, in this paper the concepts of carrying capacity and related terms are firstly reviewed, and then the difference and correlations among them are discussed. Furthermore, the suitable-degree of grazing on grassland is put forward and its connotation is defined in this paper. The major conclusions are as follows, the carrying capacity is the number of livestock that can subsist on a unit area over a specified period in theory, and the stocking rate is the number of livestock that grazes on a unit area over a specified period in practice. The carrying capacity is the upper limit of the stocking rate. If the stocking rate surpasses the carrying capacity, the grassland will be overgrazed, which will further result in the grassland degradation. In other words, the suitability-degree of grazing is the utilization intensity of grassland grazing under maximum economic profit and sustainable forage and livestock production.