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

气候变化已经影响到加拿大的北方森林，通过减少生长和大规模死亡事件，减少了炎热干旱年份的碳吸收和固存。由于这些森林储存了大量的碳，而且地理跨度很大，即使北方碳循环或物种组成发生相对较小的变化，也会对气候产生全球性影响，其中许多影响会进一步加速高纬度气候变暖。我的研究计划侧重于了解加拿大的主要北方树种如何应对高温，高二氧化碳浓度和水分胁迫，以确定近期森林衰退的机制。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经济和生态上重要的加拿大北方树种的光合作用，呼吸，水分运输和耐旱性，以及这些生理特性的适应如何影响树木的生长和生存。然后，我将使用基于过程的模型，这些模型将这些机械数据用于预测森林生产力和对干旱和热胁迫的脆弱性在未来各种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的工作已经导致了在顶级期刊上发表高质量研究的良好记录。拟议的工作将为预测加拿大森林如何应对气候变化提供重要信息，以改进森林管理计划和减缓气候变化战略。这笔赠款将使我能够直接支持五名研究生和六名本科生暑期研究人员的培训，以及十五名本科生志愿者，在紧迫的林业和压力生理学相关的问题，直接影响加拿大的经济和环境。

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.