Abstract:

By using spatial dataset of ecosystem types, ecosystem transfer matrix and dynamic degree methods, the changes of ecosystem structure and spatial distribution in Qinghai-Tibet Plateau ecological barrier area were analyzed during recent ten years. The results show that: 1) The ecosystem structure of Qinghai-Tibet Plateau ecological barrier area is relatively stable, 69% of the total land area is grassland ecosystem. 2) There are increase or decrease both in ecological and un-ecological land use, the wetland increases 2660.9 km², the grassland cuts 1377.5 km², the urban expands 224.6 km², the farmland reduces 163.4 km², and the desert reduces 1388.5 km². 3) The change rates of urban and farmland, which are significantly influenced by human activities, are distinctly higher than the wetland. For example, the urban area increases rapidly with an average annual growth rate of 2.88% and the farmland decreases 0.64% per year on average from 2000 to 2010, however the average annual growth rate of wetland is only 0.44%. 4) The overall transfer of ecosystem is small and only for 0.5% of entire study area. The areas of grassland shift to wetland and the desert shift to wetland are larger and contribute 69% to entire ecosystem transfer. 5) Both natural and human factors are the driving forces of ecosystem change, among which climate change is the main factor causing the increase of wetland area; the rapidly growth of population and GDP causes the urban expanding, but the development of industry and mining industry is the deep reason for the expansion; the increase of grazing capacity is the main cause of the grassland degradation , but the ecological protection projects play a rather positive role in grassland ecosystem recovery.

Key words: Qinghai-Tibet Plateau, ecological barrier area, ecosystem structure, dynamic changes

摘要：

以2000, 2005和2010年3期生态系统类型数据为基础, 采用生态系统转移矩阵、动态度等统计分析方法, 研究青藏高原生态屏障区近10年的生态系统结构变化及驱动因素分析。研究结果表明: 1) 近10年屏障区内生态系统结构较为稳定, 以草地生态系统为主, 约占研究区总面积的69%; 2) 生态用地与非生态用地均有增加或减少, 其中湿地增加2660.9 km², 草地减少1377.5 km², 城镇面积增加224.6 km², 农田面积减少163.4 km², 荒漠减少1388.5 km²; 3) 受人类活动影响较大的城镇、农田类型变化速率明显高于湿地等生态用地, 2000—2010年城镇面积以2.88% 的年平均增长率迅速增加, 农田面积以0.64%的年均速率持续减少, 而湿地年均增长率仅为0.44%; 4) 生态系统类型整体转移量较小, 仅为整个研究区的0.5%, 其中草地→湿地、荒漠→湿地的转移量最大, 两个转移方向的总转移比例达到69%; 5) 自然因素和人为因素是生态系统结构变化的共同驱动因素, 其中气候变化是引起湿地面积增加的主要自然因素, 人口与GDP的急速增长导致城镇不断扩张, 其深层次原因是工矿业的发展, 载畜量增加是引起草地退化的主要原因, 但生态保护工程对草地生态系统恢复具有积极作用。

关键词: 青藏高原, 生态屏障区, 生态系统结构, 动态变化