摘要
藏北高原面积60万km2,海拔4400m以上 ,气候寒冷干旱 ,是青藏高原内生态环境最酷劣的自然地域 ,大部分为无人区。境内55 %的土地为可利用的草地 ,是西藏最大的牧区 ,其绝大部分是由紫花针茅(Stipapurpurea)及青藏苔草(Carexmoorcroftii)等组成的高寒草原与高寒荒漠草原 ,虽然紫花针茅草原是当地藏绵羊的较适宜生态地域 ,但其鲜草产量不足800kg/hm2,仅在6～9月能利用 ,加上草地土壤富含砂砾 ,抗侵蚀能力弱 ,所以草地生态较脆弱。目前已有1/3的草地受沙化和侵蚀的威协 ,4 %的草地处于过牧退化状况。所以保护草地 ,维持其生态稳定乃是开发藏北高原草地资源的重要原则 ,故对高寒荒漠草原与已沙化的高寒草原须禁牧 ;大部分高寒草原的放牧强度须控制和适度 ,以求永续地利用和获得良好的经济—生态效益。
The Northern Xizang Plateau covering an area of 600,000km2 with an altitude higher than 4,000 m.a.s.l.is climatically cold and dry.So,there is no resident in most part of this physical region where the most severe eco environment is found in Qinghai Xizang Plateau.It is the largest pasture in Xizang as 55% of the total area of Northern Xizang Plateau is utilizable grassland.Of which the dominant alpine steppe and desert steppe consisting chiefly of Stipa purpurea and Carex moorcroftii are suitable for Tibetan sheep,but the output of fresh grass is less than 800kg/ha and the grazing season is limited to Jun Sep.In addition,the soils of the grassland contain much sand and gravel,very weak in resisting against erosion.So the grassland ecosystem is very fragile.Now,1/3 of the grasslands has been threatened to erosion or desertification and 4% has been degraded due to overgrazing.So the important principle for exploiting grasslands in Northern Xizang Plateau is to protect grasslands by maintaining ecological stability.Such as the alpine desert steppe with the lowest suitability for grazing and the desertified alpine steppe must be prohibited from being grazed or closed off for protection,the grazing intensity of most part of the alpine steppe should be under control or permit moderate grazing in order to guarantee sustainable utilization and get good economic ecological benefits.
出处
《自然资源学报》
CSSCI
CSCD
北大核心
2000年第4期335-339,共5页
Journal of Natural Resources
基金
中国科学院重大及特别支持项目!专题"青藏高原环境变化与区域可持续发展研究"(KZ951 -A1 -204 -05和KZ95T -06)的部分成果
关键词
藏北高原
草地资源
Northern Xizang Plateau
grassland resources
