Water quality impacts of mobilization of permafrost carbon & nitrogen in High Arctic watersheds

这项拟议的研究考察了气候驱动的永久冻土变化将如何影响北极高地流域碳(C)和氮(N)的丰度、组成和迁移。这项研究是有必要的，因为多年冻土是碳和氮的重要储存，而多年冻土的变化加强了这些重要元素的释放、转化和动员，这些元素可以显著影响地表水质量、陆地和水生生态系统功能以及大气碳收支。尽管有这些关键的潜在影响，但在融化时，来自永久冻土的碳和氮在运输和循环方面的脆弱性还没有得到很好的了解，特别是在北极高地。这种有限的认识是由于多年冻土C和N的组成和分布的不均一性，以及对控制其生产、运输和命运的水文和生物地球化学过程的不完全理解。将结合a)对永久冻土C&N来源的丰度和化学成分及其在整个地貌中的变化情况的研究，以及b)测试改变和释放永久冻土C和N的生物地球化学过程的控制的实验室实验，以及c)对更深的融化和地下水文变化如何影响地表水中C和N的输出和组成的实地调查，以弥补这些知识差距。这项研究是新颖的，因为它将碳和氮脆弱性的地球化学和水文控制与土地覆盖、特定来源和生物地球化学过程联系起来。这项研究将提供开发景观模型所需的知识，以预测永冻层变化对下游水质和生态系统的影响，并产生信息，向北极社区通报对气候变化敏感的景观和水质要素。这些结果将指导各国政府制定保护生态系统和水资源的政策，以应对当地的气候变化。高素质人员(HQP)将在邦蒂角北极分水岭天文台(CBAWO)接受培训，这是一个在加拿大北极地区独一无二的合作研究站。跨越15年变暖和永冻土变化的丰富的综合长期观测和研究遗产使CBAWO成为一个有价值的地点，可以作为北极高地分水岭应对气候变化的典范。该计划将为11个总部基地提供项目管理经验、实地和分析技能，以及评估北极流域和生态系统对气候变化的反应所需的高级知识。毕业生获得的职业生涯表明，所获得的知识和技能受到行业和政府的高度重视。HQP将为决策和制定实践做出贡献，这些实践将在不断变化的气候中改善北极环境和水资源的管理，从而造福于所有加拿大人的健康和经济福祉。

The proposed research examines how climate-driven permafrost change will impact the abundance, composition and transport of carbon (C) and nitrogen (N) in High Arctic watersheds. This research is necessitated by the fact that the permafrost is a significant store of C and N, and permafrost change stands to enhance the release, transformation, and mobilization of these important elements, which can significantly impact surface water quality, terrestrial and aquatic ecosystem function, and atmospheric C budgets. Despite the critical potential impacts, the vulnerability of permafrost-derived C and N to transport and cycling upon thaw is not well understood, especially in the High Arctic. This limited understanding is due to the heterogeneity in the composition and distribution of permafrost C and N, and an incomplete understanding of the hydrological and biogeochemical processes controlling their production, transport, and fate. These knowledge gaps will be addressed by combining a) studies of the abundance and chemical composition of permafrost C & N sources and how these vary across the landscape, with b) laboratory experiments that test the controls on the biogeochemical processes that alter and release permafrost C and N, and c) field investigations of how deeper thaw and subsurface hydrological changes affect C and N export and composition in surface waters. The research is novel as it links the geochemical and hydrological controls on C and N vulnerability to land cover specific sources and biogeochemical processes. The research will provide the knowledge necessary to develop landscape models to predict the impact of permafrost changes on downstream water quality and ecosystems and generate information to inform Arctic communities of the landscape and water quality elements that are sensitive to climate change. These results will guide governments in developing policy to protect ecosystems and water resources in anticipation of local climate change. Highly qualified personnel (HQP) will be trained at the Cape Bounty Arctic Watershed Observatory (CBAWO), a collaborative research station that is unique in the Canadian Arctic. The rich integrated long-term observations and research legacy spanning 15 years of warming and permafrost change makes the CBAWO a valuable site that can serve as a model of High Arctic watershed response to climate change. The program will provide eleven HQP with the project management experience, field and analytical skills, and advanced knowledge required to assess the response of Arctic watersheds and ecosystems to climate change. The careers secured by graduates demonstrate that the knowledge and skills acquired are highly valued by industry and government. HQP will be poised to contribute to decision-making, and the development of practices that will improve the management of Arctic environments and water resources in a changing climate, and thus benefit the health and economic well being of all Canadians.