黑河流域草地承载力研究

应用RS和GIS技术,从研究区植被类型、土壤侵蚀、坡度、距水源距离、生物多样性和生态系统保护等方面,确定了黑河流域不适合和适合放牧的区域。在适合放牧的区域,根据草地类型估测产草量。在牧草分配方面,从避免土壤侵蚀和遭遇干旱时保证植被群落弹性和再生的需要以及满足昆虫和土壤无脊椎动物及野生动物需要两个方面考虑了满足生态需要的牧草生物量。在确定放牧强度时,从坡度和距离水源远近两个方面考虑了载畜量的减少比例。在此基础上,计算出满足生态保护需要的草地承载力。研究结果表明,黑河流域适合放牧的区域仅占总面积的17.693%,在适合放牧的区域,天然草地的承载力为0.009～2.055只羊单位/hm²。

Study on Grassland Grazing Capacity in the Heihe River Basin

Using RS & GIS techniques,the areas suitable for livestock grazing in the Heihe River Basin were identified based on natural conditions such as vegetation types,soil erosion,slope,distance to water,as well as the need of conservation for biological diversity and ecosystem.In those areas suitable for livestock grazing,the forage production was estimated for each individual grassland type based on the past surveys.The allotments of forage for ecological needs were taken into account from following two aspects.The first aspect includes the allotments of forage for soil resistance to erosion,ensuring plant community resilience and regeneration under drought season.The second aspect includes those for insects,nematodes,wildlife habitat needs.Reductions in grazing capacity are adjusted by distance to water and slope. On the above bases,the grassland grazing capacity that meets the ecological needs in the Heihe River Basin is calculated.The study indicates that the area of capability and suitability for livestock grazing is 17.693% of the total land area and natural grassland grazing capacity is at the ranges from 0.009 to 2.055 sheep/hm2.