Assessing impacts of climate change, extreme weather events and management regimes on biogeochemical and hydrological cycles in Canadian forest ecosystems

评估气候变化、极端天气事件和管理制度对加拿大森林生态系统生物地球化学和水文循环的影响

• 批准号: RGPIN-2020-06028
• 负责人: Arain, Muhammad
• 金额: $ 3.72万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=718165
• 关键词: Assessing; impacts; climate; change; extreme

Canada's forest ecosystems, which represent about 40% or 397 Mha of the country' surface area, are being severely affected by climate change and extreme weather events such as droughts, flooding, and heatwaves. Climate warming is therein accelerating the hydrological cycle, thereby altering the growth, water balance, disturbance regimes (insect, fire), soil plant nutrient cycling and associated feedbacks (IPCC 2013, 2018). Changes in the composition, structure and functioning of forest ecosystems can affect regional climate and hence enhance the vulnerability of water resources and human communities. Developing a clear understanding of functioning of forest ecosystems and their response to climatic change and extreme events is urgently needed to maintain (or enhance) their capacity to sequester atmospheric CO2, and preserve ecosystem services. This proposal will investigate the impact of changes in forest hydrology and nutrient cycling on the carbon sequestration potential of three different age conifer and a deciduous forest and explore how these forests will respond to future climate change and extreme weather events. It will assess how different forest management treatments (e.g. variable retention harvesting (VRH)) will impact the forest growth trajectory, energy exchanges, hydrological processes in response to future climatic stresses and extreme events (e.g. drought, heat). This research will utilize ground based (e.g. eddy covariance, soil CO2 efflux, sapflow, biometric) and airborne (e.g. drone and satellite remote sensing) datasets to explore, how different age- and species forests as well as management regimes (thinning intensities and spatial patterns) influence stand water use and productivity and response to extreme events and environmental variability. Proposal will also focus on to further develop a process- based integrated biogeochemical and hydrological model to enhance predictive capabilities of energy, water, carbon and nutrient cycles at stand and watershed scales across Canada. It will build on existing modelling work where C and N coupled Canadian Land Surface Scheme Canadian Terrestrial Ecosystem Model (CLASS-CTEM-N+) has been incorporated in the MESH Hydrological system to develop an integrated hydrological and biogeochemical model, called MESH-CTEM. Quantification of the responses of managed forests to climate change will help environmental planners to develop climate adopted forest management practices. MESH-CTEM modelling work will allow exploration of post-disturbance (management and/or fire) growth trajectories of Canadian forests under climate change in different watersheds and climate zones across Canada. Further development of CLASS and CTEM models will help to advance predictive capabilities of the Canadian regional and global climate models such as Canadian Earth System Model (Can-ESM) and provide an assessment tool to generate scenarios of future climate for policy development by the Federal Government.

加拿大的森林生态系统代表该国的表面积约40％或397 MHA，受到气候变化和极端天气事件的严重影响，例如干旱，洪水和热浪。气候变暖正在加速水文周期，从而改变了生长，水平，干扰状态（昆虫，火），土壤植物养分循环和相关的反馈（IPCC 2013，2013）。森林生态系统组成，结构和功能的变化会影响区域气候，从而增加水资源和人类社区的脆弱性。迫切需要对森林生态系统的功能及其对气候变化和极端事件的反应有清晰的了解，以维持（或增强）其隔离大气二氧化碳的能力，并保留生态系统服务。该提案将研究森林水文和营养循环的变化对三种不同年龄针叶树和落叶林的碳封存潜力的影响，并探索这些森林将如何应对未来的气候变化和极端天气事件。它将评估不同的森林管理处理（例如可变保留收获（VRH））如何影响森林生长轨迹，能量交流，水文过程，以响应未来的气候应力和极端事件（例如干旱，热量）。这项研究将利用基于地面的（例如涡流协方差，土壤CO2流出，SAPFLOF，生物识别）和机载（例如无人机和卫星遥感）数据集探索，不同的年龄和物种森林以及管理方案以及管理方案（稀疏性和空间模式）如何影响水和生产力和生产力和环境和环境和环境的变异性。提案还将着重于进一步开发基于过程的综合生物地球化学和水文模型，以增强在加拿大整个加拿大的架子和分水岭的能源，水，碳和养分周期的预测能力。它将建立在现有的建模工作的基础上，其中C和N偶联的加拿大陆地表面加拿大陆地生态系统模型（Class-ctem-N+）已纳入网格水文系统中，以开发一种综合的水文和生物地球化学模型，称为网状CTEM。量化托管森林对气候变化的反应将有助于环保计划者开发通过的气候采用的森林管理实践。网格CTEM建模工作将允许在加拿大各地不同流域和气候区域的气候变化下探索加拿大森林的陷入后扰动（管理和/或火灾）的生长轨迹。班级和CTEM模型的进一步开发将有助于提高加拿大地区和全球气候模型（例如加拿大地球系统模型（CAN-ESM））的预测能力，并提供了一种评估工具，以生成联邦政府未来的政策制定气候的情景。