关键词: 青藏高原, 生态屏障区, 生态系统结构, 动态变化

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