Evaluating the capabilities of Eastern Canadian forest ecosystems to sequester atmospheric CO2 and their response to climate change

大气中二氧化碳和其他温室气体水平的上升是科学家和政策制定者关注的问题，因为它们捕获了从地球发出的长波辐射，导致了我们的大气变暖。最近发布的第四份联合国政府间气候变化专门委员会报告得出结论，气候系统变暖是明确的，很可能是人为温室气体造成的。加拿大将其森林视为潜在的碳(C)汇。然而，由于与生物碳汇相关的不确定性，特别是在森林中，加拿大政府尚未决定是否采用生物碳汇选项来抵消化石燃料的排放。未来气候变暖可能会对加拿大森林生态系统的健康和生长产生严重影响，加拿大森林生态系统已经受到当前气候变暖条件的严重影响。这项战略赠款提案(SGP)侧重于评估加拿大东部三个主要森林生态系统的能力，即针叶树龄序列(65、35、5年生)、落叶和混交林，以固定大气中的二氧化碳及其对未来气候变化(如变暖、干旱等)的反应。该SGP还将侧重于开发一个氮(N)循环模型，并将其纳入加拿大陆地生态系统模型(CTEM+N)。CTEM+N将用于探索在未来各种气候变化情景下，自然和人为效应(即N沉积增加、CO2施肥、严重干旱和洪涝事件、温度胁迫等)对所有三种森林生态系统(针叶、落叶和混交林)模拟的C和水分交换的影响。量化加拿大东部所有三个主要森林生态系统对气候变化的反应将使环境规划者和管理人员能够制定战略，帮助这些生态系统更好地适应未来的气候变化。在加拿大全球气候模式中实施CTEM+N将提供一种评估工具，以便为政策制定制定未来气候情景，并帮助加拿大履行其国际义务。

Rising levels of atmospheric CO2 and other greenhouse gases are a concern to scientists and policy-makers, because they trap longwave radiation emitted from Earth, contributing to our atmosphere's warming. Recently released fourth UN IPCC report concluded that warming of the climate system is unequivocal and very likely due to anthropogenic greenhouse gases. Canada considers its forests as a potential carbon (C) sink. However, Canadian government has not yet decided whether it will adopt the biological C sink option to offset fossil fuel emissions, due to uncertainties associated with biological C sinks, particularly in forests. Future warming of the climate may have a severe impact on the health and growth of Canadian forest ecosystems, which are already being seriously affected by current warmer climatic conditions. This Strategic Grant Proposal (SGP) focuses on evaluating the capabilities of three key Eastern Canadian forest ecosystems, a conifer age-sequence (65, 35, 5 year old), deciduous, and mixedwood stands, to sequester atmospheric CO2 and their response to future climate change (e.g. warming, drought, etc.). This SGP would also focus on developing and incorporating a nitrogen (N) cycle model in the Canadian Terrestrial Ecosystem Model (CTEM+N). CTEM+N will be used to explore the impact of natural and anthropogenic effects (i.e. increased N deposition, CO2 fertilization, severe drought and flooding events, temperature stresses, etc) on simulated C and water exchanges in all three (conifer, deciduous and mixedwood) forest ecosystems under various future climate change scenarios. Quantification of the responses of all three major Eastern Canadian forest ecosystems to climate change would equip environmental planners and managers to develop strategies that may help these ecosystems to better adapt to future climate change. Implementation of CTEM+N in the Canadian Global Climate Model would provide an assessment tool to generate scenarios of future climate for policy development and help Canada meet its international obligations.