DISSERTATION RESEARCH: Impacts of global warming at high elevation tree lines in the Himalayas

人为气候变化造成的气温上升在高海拔地区往往特别明显，威胁到许多物种的生存。该项目将研究尼泊尔喜马拉雅山相对原始的森林中，海拔约4000米的树木上界如何对气候变化作出反应。初步研究表明，一种占优势的树木，杜鹃花属的上海拔边界正在迅速向上移动，在最高海拔的个体对极端气候条件的耐受性更强，但对竞争的耐受性低于仅低150米的个体。 该项目将扩大这项工作，以包括更多的措施，个人和网站之间的差异，不同的关键特征，如外观和降雨量。 研究结果将有助于显示山地物种如何应对气候变化，如何响应可能取决于物种或网站的具体情况之间的相互作用，以及哪些机制驱动高海拔范围的变化，并确定当地灭绝的相关风险。该项目将对学生进行实地方法培训，并为他们提供探索远离城市的自然地区的机会。此外，该项目将在得克萨斯大学和特里布万大学的研究人员与尼泊尔科学技术学院之间形成新的国际合作。联合PI将在加德满都为本科生和研究生讲授短期课程，内容涉及生态学、气候变化研究和先进统计工具的当前趋势。 将在朱姆拉和加德满都向公众进行外联介绍，以提高他们对气候变化及其对生活影响的认识。

Temperature rise from anthropogenic climate change is often especially pronounced at high elevations, where it threatens the survival of many species. This project will study how the upper elevational boundary of trees at about 4000 m is responding to climate change in relatively pristine forests of the Nepal Himalayas. Preliminary work suggests that the upper elevational boundary of one of the dominant trees, a species of Rhododendron, is rapidly shifting upward, with individuals at the highest elevations being more tolerant to extreme climate conditions but less tolerant of competition than individuals only 150 m lower. This project will expand this work to include additional measures of differences between individuals and sites that differ in key characteristics such as aspect and rainfall. Results will help show how montane species respond to climate change, how responses may depend upon interactions between species or site specifics, and which mechanisms drive shifts in range at high elevation and determine associated risks of local extinction. The project will train students in field methods and provide them with an opportunity to explore natural areas distant from cities. Additionally, the project will form a new international collaboration between researchers at the University of Texas and Tribhuvan University and the Nepal Academy of Science and Technology in Nepal. The co-PI will teach short courses to undergraduate and graduate students in Kathmandu on current trends in ecology, climate change research, and advanced statistical tools. Outreach presentations to the general public will be given in Jumla and Kathmandu to increase their awareness of climate change and its impacts on their lives.