Collaborative Proposal: Determining the Vulnerability and Resilience of Boreal Forests and Shrubs across Northwestern North America

寒带和北极景观的重要性被科学界视为一个重要的研究领域。在这个提议中要测试的首要理论是，目前对植被生长的控制并不像过去那样有效。调查人员手头有一个详细的树木年轮地面测量网络，这些数据收集自阿拉斯加和邻近加拿大的一系列北方和北极森林和灌木地。这些数据将与基于卫星的植被生产力遥感代用品进行比较。总的来说，这项工作是对评估北极生态系统中植被生长变异性的两种独立方法的分析和比较。该项目将有助于公众教育（例如年度开放日展览，网站，来自该领域的博客），并将部分资助博士后研究人员，他们将有机会扩大他们在该主题的科学经验和知识。这项工作将集中在阿拉斯加和邻近加拿大的北方和北极森林和灌木丛上，这些地区正在经历当今全球最迅速的变暖。卫星观测揭示了北纬高纬度地区显著的植被生产力趋势（变绿和褐化），北美和欧亚大陆北部生物群落之间以及冻土带和北方地区之间存在明显差异。与此同时，一些观测表明，近几十年来，北方树木生长与温度之间的强相关性似乎正在减弱。在这个提议中要测试的首要理论是，目前对植被生长的控制并不像过去那样有效。调查人员手头有一个详细的网络，对从该地区收集的树木年轮数据进行实地测量。这些数据将与阿拉斯加和邻近加拿大的一系列北方和北极森林和灌丛地的植被生产力遥感代用物（来自卫星NDVI）进行比较。这项工作将包括在高优先区域一年的实地数据，在那里调查人员将提取最新的树木年轮核心，以便与最近的气温和遥感记录进行比较。

The importance of Boreal and Arctic landscapes is recognized by the scientific community as an important area of research. The overarching theory to be tested in this proposal is that the current controls over vegetation growth are not operating as they have been in the past. The investigators have at hand a detailed network of ground measurements of tree-ring data collected across a range of Boreal and Arctic forests and shrublands sites in Alaska and adjacent Canada. This data will be compared with satellite based remote sensing proxies of vegetation productivity. The work is by and large an analysis and comparison of two independent methods for assessing vegetation growth variability in Arctic ecosystems.This project will contribute to the education of the general public (e.g. annual open house exhibits, websites, blogs from the field), and will partially fund a post-doctoral researcher who will have the opportunity to expand their scientific experience and knowledge of this topic.This work will focus on Boreal and Arctic forests and shrublands across Alaska and adjacent Canada, regions that are experiencing some of the most rapid warming on the globe today. Satellite observations have revealed significant vegetation productivity trends (both greening and browning) of vegetation at high northern latitudes, with distinct differences between North America and northern Eurasia biomes and between tundra and boreal regions. At the same time, some observations show that the strong correlation between northern tree growth and temperature appears to be weakening in recent decades. The overarching theory to be tested in this proposal is that the current controls over vegetation growth are not operating as they have been in the past. The investigators have at hand a detailed network of in situ ground measurements of tree-ring data collected from across this region. This data will be compared with remote sensing proxies of vegetation productivity (from satellite NDVI), across a range of Boreal and Arctic forests and shrublands sites in Alaska and adjacent Canada. The work will include one year of field data in regions of high priority where the investigators will extract up to date tree ring cores for comparison with recent air temperature and remote sensing records.