Climate Change Impacts on Boreal Tree Function: Implications for Carbon and Water Fluxes

气候变化已经在影响加拿大的北方森林，在炎热干燥的年份，通过生长放缓和大规模死亡事件，减少了碳的吸收和封存。由于这些森林中储存了大量的碳，而且它们的地理跨度很广，即使是北部碳循环或物种组成的相对较小的变化也可能对全球气候产生影响，其中许多变化可能会进一步加速高纬度气候变暖。我的研究计划重点是了解加拿大主要的北方树种对高温、高二氧化碳浓度和水分胁迫的反应，以确定最近森林衰退的机制。在接下来的五年里，我的实验室将专注于评估这些气候变化因素如何改变加拿大北方重要的经济和生态树种的光合作用、呼吸作用、水分运输和抗旱性，以及这些生理特征的驯化如何影响树木的生长和存活。然后，我将使用基于过程的模型来获取这些机械数据，并使用它来预测森林生产力以及对干旱和高温胁迫的脆弱性在各种未来气候情景下将如何变化。我在理解功能树对全球变化环境因素的反应方面所做的工作，已经在顶级期刊上发表了高质量的研究成果。拟议的工作将为预测加拿大森林将如何应对气候变化提供关键信息，以改进森林管理计划和气候变化缓解战略。这笔赠款将使我能够直接支持培训五名研究生和六名本科生暑期研究人员，以及十五名本科生志愿者，以应对直接影响加拿大经济和环境的林业和生理学相关问题。

Climate change is already affecting Canada's boreal forest, reducing carbon uptake and sequestration during hot, dry years through reduced growth and large-scale mortality events. Because of the vast amount of stored carbon in these forests and their extensive geographic span, even relatively small changes in boreal carbon cycling or species composition can have global impacts on climate, many of which can further accelerate high latitude climate warming. My research program focuses on understanding how Canada's major boreal tree species respond to elevated temperatures, high CO2 concentrations and water stress, to determine the mechanisms underlying recent forest decline. Over the next five years, my lab will focus on assessing how these climate change factors alter photosynthesis, respiration, water transport, and drought tolerance in economically and ecologically important Canadian boreal tree species, as well as how acclimation of these physiological traits affects tree growth and survival. I will then use process-based models that take this mechanistic data and use it to predict how forest productivity and vulnerability to drought and heat stress will change under various future climate scenarios. My work on understanding functional tree responses to global change environmental factors has already led to a strong record of publishing high-quality research in premier journals. The proposed work will provide crucial information for predicting how Canada's forests will respond to climate change to improve forest management plans and climate change mitigation strategies. This grant will allow me to directly support the training of five graduate students and six undergraduate summer researchers, as well as fifteen undergraduate student volunteers, in pressing forestry and stress physiology-related issues that directly impact Canada's economy and environment.