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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=664616
• 关键词: Biological; landscape; controls; net; greenhouse

Since the 1950's, annual air temperatures over Arctic landmasses have risen between 2°C and 3°C, while winter temperatures have increased as much as 4°C. 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，北极陆地上的年气温上升了2°C到3°C，而冬季气温上升了4°C。这些变暖的温度可能导致北极陆地生态系统的级联变化，例如：降水增加导致的水文循环改变、植物群落分布的转移、地表性质的改变，如地表反照率的降低，以及永久冻土融化的增加。永久冻土含有全球大约一半的土壤碳库，因此永久冻土融化导致的碳损失率增加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，增加植物生产力和碳储量，对未来的变暖产生负面反馈。为了预测未来北极生态系统对气候变化的响应，我们需要在一定的时空尺度上了解北极高纬度生态系统的关键温室气体循环过程。*******在梅尔维尔岛上的邦蒂角北极流域观测站（cawo），我将探索植被分布与气候变化之间的相互作用如何改变北极高纬度生态系统的净温室气体平衡。具体来说，我将研究1)苔藓对温室气体净通量的贡献，以及苔藓与土壤水分之间的相互作用2)极地半荒漠群落对北极高纬度地区甲烷净平衡的贡献，以及3)温度、湿度、活动层深度、太阳辐射和基于卫星的植被特性估计如何相互作用，以控制北极景观的温室气体净平衡。我将使用现场和实验室测量相结合的方法来探索这些问题，包括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，以及我在这里工作的同事们的研究结果，将被整合到一个最先进的流域尺度生物地球化学模型中，该模型将为该地区未来如何应对气候变化提供见解。我的研究将通过为4名硕士、1名博士和5名本科生提供跨学科培训来帮助培养下一代北极科学家，这些培训也为许多环境职位提供了关键技能。我的研究结果将提供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，预测北极生态系统对未来气候的贡献。******