亚洲中部干旱区高山林线变化及其驱动机制研究展望

Prospects on alpine timberline change and its driving mechanism in arid area of Central Asia

气候变化对森林的影响和森林对气候的反馈作用是全球变化研究前沿,也是森林生态学重要研究方向之一。全球变化对森林的影响存在明显的区域差异,亚洲中部干旱区山地森林在全球变暖背景下正经历着显著变化,其中以高山林线的变化最具代表性。植被带谱清晰的天山北坡近50 a气候变异明显,是研究高山林线变化的理想区域。采用摄影测量技术及高分辨率遥感影像解译手段等新技术、新方法加强对亚洲中部干旱区高山林线变化的探讨,揭示近50 a来亚洲中部干旱区高山林线森林上限和下限变迁特点与过程;并利用Landsat TM、Terra/Aqua MODIS、AMSR_E等遥感影像、气象和测点数据,定量反演林线内土壤温度、水分、冠层温度等控制森林分布与生长发育的关键环境因子的时空变化,揭示林线变迁驱动机制,将深化山地森林生态系统对气候变化响应的认识,并丰富森林生态学的内容。

The impact of climate change on forests and the feedback of forests to the climate are the focus of study on global change as well as one of the important research topic in forest ecology.The impact of the global change on forests represents significant regional variation.In the arid area of the Central Asia,the mountainous forests are changing notably with the global warming,especially for the change of the alpine trimline.On the north slope of the Tianshan Mountains with clear vegetation spectrum,the climate changed significantly in the latest 50 years,which is the ideal region for researching changes of the alpine trimline.Photogrammetry and interpretation of the satellite images with high resolution are the new techniques and methods to enhance exploration of alpine trimline change in this area,which is helpful for researching the feature and process of the variations occurring near the forest upper and lower limits of the trimline.Retrieving the key environmental variables,e.g.soil temperature,soil moisture and canopy temperature,using Landsat TM,Terra/Aqua MODIS and AMSR-E data,meteorological data and ground-based observations can prompt study on the driving mechanism of the trimline change,this will further deepen the understanding of the response of the mountainous forest ecosystem to climate change,and enrich the contents of the forest ecology.