青藏高原高寒生态区生态系统脆弱性时空变化及驱动机制分析

Analysis of spatial and temporal changes and its driving mechanism of ecological vulnerability of alpine ecosystem in Qinghai Tibet Plateau

全球气候变化和人类活动胁迫下,青藏高原高寒生态区的脆弱生态系统正在发生深刻变化。研究在充分考虑研究区生态环境本底特征(高寒、冻融侵蚀、盐渍化、水力侵蚀强烈)的基础上,引入了极端气候事件因子(极端高温、极端低温、极端降水)和人类活动干扰因子构建了青藏高原高寒区生态系统脆弱性评价体系,进而对研究区近13年的生态系统脆弱性时空变化格局及其驱动机制进行了分析。研究结果表明:青藏高原高寒生态区的生态系统脆弱性总体上属于中度脆弱状态,其空间分布格局自东南向西北呈现递增趋势;2000—2013年,青藏高原高寒生态区总体的生态系统脆弱性表现为先增加后减小的趋势;生态系统脆弱性时空变化分异格局与地形、气候(气温、降水等)、人口密度存在显著地相关性。相关研究成果可以为青藏高原脆弱生态环境的保护和修复提供决策支持。

Under the influence of global climate change and human activities,the fragile ecosystem in the Qinghai Tibet Plateau is undergoing profound changes.In this study,fully considering the ecological environment background characteristics（freeze-thaw erosion,salinization,soil water erosion）,we introduced the extreme climate events factor（extreme high temperature and low temperature,extreme precipitation）and human disturbance factors to construct the evaluation system of fragile ecosystem in the Tibetan Plateau,and then the temporal and spatial patterns of ecosystem vulnerability changes and its driving factors were analyzed.The results showed that the ecosystem vulnerability of alpine ecological fragile region in Qinghai-Tibet Plateau belonged to the level of moderate vulnerability.The spatial distribution pattern showed an increasing trend from southeast to northwest.During 2000-2013,the ecosystem vulnerability firstly increased and then decreased.There was a significant correlation between the spatial and temporal variation patterns of ecosystem vulnerability and topography,climate（temperature,precipitation）,and population density.The research results can provide decision support for the protection and restoration of the fragile ecological environment in Qinghai Tibet plateau.