摘要
以江河源区退化高寒草甸为对象,利用层次分析法,探讨了高寒草地的退化原因和恢复治理措施的有效性。结果表明:长期超载过牧和暖干化气候是导致高寒草甸退化的主导因子,贡献率为65·99%;伴随草地初始退化出现的鼠虫和毒杂草泛滥危害是加速高寒草甸退化的重要因子,贡献率为15·03%;人类不合理干扰造成的高寒草甸退化也不应忽视,贡献率为9·64%。各个恢复治理措施组合权重的分配格局相对均衡,其中围栏封育和划区轮牧(E2)与控制放牧强度(E1),效益较好,组合权重达0·3007。层次分析法可为草原管理,防止草地退化、恢复治理退化草地、优化利用草地资源提供定量依据。
The degradation of alpine grassland is serious in the source region of the Yangtze and Yellow Rivers. The area of degraded grassland is 357.13×10~4 ha, accounting for a third of available grassland in the region. Serious grassland degradation has brought great impacts to local ecological environments, biodiversity conservation, and animal husbandry development. Analytic Hierarchy Process (AHP) was adopted for analyzing the causes of alpine grassland degradation and efficiency of different restoring measures were evaluated in the region. The results shown that Long-term over-grazing process, warming and drying climate are the main causes of alpine grassland degradation with a contribution of 65.99%. The damages from hedgeshrew and pest as well as rampant toxic weeds are coupling with the primitive degradation and accelerating the process of alpine grassland degradation, attribution to 15.03%. Human activities rank in the third place with a contribution rate of 9.64% to alpine grassland degradation. Except for the natural factors such as warming and drying climate, and freeze-thaw erosion, there are four others of anthropic factors contributing to alpine grassland degradation. The contribution of natural factors to alpine grassland degradation accounts for 31.96%, while anthropic factors accounting for 68.04%. These data revealed that about 70% of alpine meadow degradation is caused by human irrational disturbance and about 30% attribute to natural factors. Moreover, improper grassland management such as long-term over-grazing, rampant toxic weeds, introduction of invasive species, and irrational structure of livestock cause alpine grassland degradation directly and indirectly. The contribution of improper grassland management to alpine meadow degradation reaches to 58.40%. The integrated weight values reflect the integrated effects of restoring measures on different causes of alpine grassland degradation. The distributing pattern of integrated weight value of different restoring measures is equilibratory. The fencing, rotating grazing system (E2) and decreasing grazing intensity (E1) are better than other measures with the integrated weight value of 0.3007. The integrated weight values of pest harm control (E4), human irrational disturbance control (E5) and restoring degraded grassland by fertilizing, reseeding and loosing (E6) are larger than 0.1200. The integrated weight values of optimization of livestock structure (E7) and selection of high quality cultivars (E8) are less than 0.1200. The study shown that the AHP can provide meaningful data for improving grassland management, preventing grassland from degradation, restoring degraded grassland and grassland optimal utilization as well.
出处
《资源科学》
CSSCI
CSCD
北大核心
2005年第4期63-70,共8页
Resources Science
基金
国家"十五"科技攻关项目课题"江河源区退化草地治理技术与示范"(编号:2001BA606A-02)。
