Biological and landscape controls on the net greenhouse gas balance of High Arctic ecosystems

对高北极生态系统温室气体净平衡的生物和景观控制

• 批准号: RGPIN-2017-05921
• 负责人: Scott, Neal
• 金额: $ 1.6万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754825
• 关键词: Biological; landscape; controls; net; greenhouse

Since the 1950's, annual air temperatures over Arctic landmasses have risen between 2C and 3C, while winter temperatures have increased as much as 4C. These warmer temperatures could induce cascading changes to terrestrial Arctic ecosystems, such as: altered hydrological cycles from increasing precipitation, shifting distribution of plant communities, altered surface properties such as decreased surface albedo, and increased permafrost thawing. Permafrost soils contain approximately half of the global soil carbon reservoir, so an increased rate of carbon loss due to permafrost thawing could accelerate future climate change. At the same time, permafrost thawing could liberate plant nutrients, increasing plant productivity and carbon storage, creating a negative feedback on future warming. To predict the future response of arctic ecosystems to changes in climate, we need to understand key greenhouse gas (GHG) cycling processes in high Arctic ecosystems at a range of spatial and temporal scales.At the Cape Bounty Arctic Watershed Observatory (CBAWO) on Melville Island, I will explore how the interactions between vegetation distribution and climate change alters the net GHG balance of high Arctic ecosystems. Specifically, I will examine 1) the contribution of mosses to net GHG fluxes, and the interaction between mosses and soil moisture 2) the contribution of polar semi-desert communities to the net methane balance of the high Arctic, and 3) how temperature, moisture, active layer depth, solar radiation, and satellite-based estimates of vegetation properties interact to control the net GHG balance across Arctic landscapes. I will explore these questions using a combination of field and laboratory measurements, including state-of-the-art automated chambers to measure carbon dioxide fluxes at high temporal frequencies and soil molecular techniques to characterize the bacteria responsible for methane production and consumption. My results, along with those of my colleagues working at this site, will be integrated into a state-of-the art watershed scale biogeochemistry model that will provide insights into how the region might change in the future in response to changes in climate. My research will help train the next generation of Arctic scientists by providing interdisciplinary training to 4 MSc, 1 PhD, and 5 undergraduate students - the training also provides key skills for many environmental positions. Results from my research will provide insights into how terrestrial ecosystems will respond to climate change, and help develop improved models that predict the contribution of Arctic ecosystems to future climate.

自 20 世纪 50 年代以来，北极大陆的年气温上升了 2 至 3 摄氏度，而冬季气温则上升了 4 摄氏度。这些温暖的气温可能会引起北极陆地生态系统的级联变化，例如：降水量增加导致水文循环的改变、植物群落分布的变化、地表特性的改变（例如地表反照率的降低）以及永久冻土融化的增加。永久冻土约占全球土壤碳库的一半，因此永久冻土融化导致的碳流失速度加快可能会加速未来的气候变化。与此同时，永久冻土融化可以释放植物养分，提高植物生产力和碳储存量，对未来变暖产生负反馈。为了预测北极生态系统对气候变化的未来反应，我们需要在一定的空间和时间尺度上了解北极高海拔生态系统中关键的温室气体（GHG）循环过程。位于梅尔维尔的邦蒂角北极流域观测站（CBAWO）在岛上，我将探讨植被分布与气候变化之间的相互作用如何改变北极高海拔生态系统的温室气体净平衡。具体来说，我将研究 1) 苔藓对净温室气体通量的贡献，以及苔藓和土壤水分之间的相互作用 2) 极地半沙漠群落对高北极净甲烷平衡的贡献，以及 3) 温度、水分、活动层深度、太阳辐射和基于卫星的植被特性估计相互作用，控制整个北极景观的净温室气体平衡。我将结合现场和实验室测量来探索这些问题，包括使用最先进的自动化室来测量高时间频率下的二氧化碳通量，以及土壤分子技术来表征负责甲烷产生和消耗的细菌。我的研究结果以及在该地点工作的同事的研究结果将被整合到最先进的流域规模生物地球化学模型中，该模型将提供有关该地区未来如何因气候变化而发生变化的见解。 我的研究将通过为 4 名硕士生、1 名博士生和 5 名本科生提供跨学科培训来帮助培训下一代北极科学家 - 该培训还提供许多环境职位的关键技能。 我的研究结果将提供有关陆地生态系统如何应对气候变化的见解，并有助于开发改进的模型来预测北极生态系统对未来气候的贡献。