岷江上游地区的草地资源与畜牧业发展

岷江上游草地面积837226hm^2,大约占了该区土地面积的35％。这块草地蕴藏着丰富的生物多样性,具有重要的生态学功能,是岷江上游绿色生态屏障的重要组成部分。高山草甸草地和亚高山草甸草地是该区的主要植被类型,其面积分别占草地总面积的54．8％和17．2％,其产草量分别占该区各类草地总产草量的53．47％和26．46％。岷江上游各县天然草地的面积和各县草地畜牧业在经济结构中所占的比重都表现了从高海拔到低海拔递变的趋势,基本上与植被的垂直梯度变化相耦合。指出了当前草地畜牧业发展存在的一些问题：超载过牧现象严重,生产效率低下,集约化水平低。除了饲草的生产与加工、畜种改良和草种改良等措施外,结合岷江上游的实际情况,在发展的思路和技术措施上着重阐述了以下几个方面：发展特色畜牧业,摒弃头数畜牧业;以市场为导向的主动畜群时空周转;结合“天保工程”和“退耕还林工程”,促进农林牧业的紧密结合。

GRASSLAND RESOURCE AND MOUNTAIN PASTORALISM DEVELOPMENT ON THE UPPER REACHES OF MINJIANG RIVER

Grassland accounts for 35% of its total 837 226 hm\+2 land area in the upper region of Minjiang River, Sichuan Province. It is of great importance as the repositories of rich biological diversity and the core part of the "ecological screen" in Western Sichuan. Alpine meadow accounts for 54.8% of the total grassland area, while the sub-alpine meadow ranks the second, accounting for 17.2%. They are also the two major types of grasslands with the highest gross grass production, which account 53.47% and 26.46% respectively. The grassland area in different counties shows a tendency that grassland area is corresponding with vertical changes of vegetation and elevation, so does the proportion of pastoral in gross agricultural output.The problems in pastoralism development are pointed out, i.e. overstocking, genetic degradation of both livestock and forage plants, and low productivity in management. In the light of local special conditions, following measures and thoughts are emphatically disscussed , i.e. to abandon number pastoralism and develop distinctive pastoralism which means higher efficiency and lower pollution; and to develop market-oriented active livestock ; according to "the engineering of protecting natural forest" and "the engineering of restoring forest and grassland that have ever been brougt under cultivation", to develop artificial grassland and forage woods.