内蒙古典型草原草畜系统适宜放牧率的研究Ⅱ.以牧草地上现存量和净初级生产力为管理目标

The Optimal Stocking Rate on Grazing System in Inner Mongolia Steppe Ⅱ. Based on Relationship Between Stocking Rate and Aboveground Net Primary Productivity

本文以放牧管理中放牧率与牧草地上现存量及净初级生产力之间的关系，分析和探讨内蒙古典型草原草-畜系统的适宜放牧率。尽管草原地上现存量随着放牧率的增大而降低，采食率随着放牧率的增大而增大，但最大地上净初级生产力则以2．67羊／hm2最大。结果表明，在冷蒿小禾草退化草原，确定最大地上净初级生产力的适宜放牧率，既要考虑地上现存量的大小，又要兼顾采食量，因而将草原状况与放牧率有机结合，综合的判断标准较为适用。此类退化草原最大地上净初级生产力的放牧率约为2．7羊／hm2，此时，个体增重和公顷增重分别为最大个体增重和公顷增重的87％和70％以上。因此，冷蒿退化草原的最大放牧率不应超过该放牧率值。

The objective was to study the realtionship between stocking rate and aboveground present biomass(APB) and aboveground net primary productivity (ANPP) based on the degraded rangeland of Artemisia frigida and short-grasses. The results showed that although the APB decreased with increase of stocking rate and intake rate of herbage increased with increase of stocking rate, the ANPP was the maximum in the stocking rate of 2. 67 sheep unit/ha in 1993 and 1997. The stocking rate of the maximum ANPP is the best for grazing system,espicially for degraded rangeland of Artemisia frigida and short -grasses.