Impacts of Talik Microbial Geochemistry on a Changing Permafrost Landscape

拟议的研究计划采用跨学科的方法来调查湖泊和池塘下的岩层的水文、地球化学和微生物学，这些岩层被定义为永久冻土区的一层或一层未冻结的土壤。这些暗礁在水文上与地表水相连，但由于长时间的大范围冰盖和进入它们本身的困难，人们对它们知之甚少。虽然多年冻土产生了一个有效的屏障，可以隔离谈话中的微生物群落，但北极气候变暖的速度是全球平均水平的两倍，正在导致永久冻土的分布和厚度的减少，这将减少这些障碍并导致塔里克膨胀，这在考虑到永久冻土中大量土壤有机碳的微生物呼吸和相关的热岩溶湖泊释放甲烷时非常令人担忧。北极也正在经历巨大的水文和水文地质变化，导致地表水和地下水之间的相互关系迅速演变。由于水文流动路径和物理化学条件的变化，这影响了地上和地下储存的水的分配以及地表水与地下水环境的连通性。这些与气候有关的影响将对塔里克环境产生重大影响，但这些影响对微生物多样性和生物地球化学的影响程度和程度以及它们今后与地表水的相互联系尚不清楚。HQP牵头的项目将产生关于连续和不连续永久冻土区三个实地地点的湖泊和池塘下的谈话范围和组成的新知识。它将识别和绘制这些岩层及其与其他地下特征的相互联系，测量和比较这些岩层的热、水文地球化学和微生物特性，并确定塔里克岩层的特性如何影响邻近的水和沉积环境，如上覆水域或近岸环境。HQP将在这些地点进行广泛的实地考察，并精通地球物理、地球化学、宏基因组学和显微技术。除了通过19个HQP的科学工作产生的新知识外，该计划还将直接造福于关注气候变暖对淡水环境影响的北方社区。此外，通过这些努力，加拿大公民将直接受益于更好地了解北极陆地景观。他们的知识将帮助社会了解气候变暖如何影响北极，并将指导现在和未来的政策制定者决定加拿大如何应对全球气候变化。最后，通过开展由总部基地牵头的项目，其中包括5名北部社区成员，这项工作将有助于增强这些社区了解和准备应对气候变暖导致的未来水文和地球化学变化的能力。

The proposed research program takes an interdisciplinary approach to investigate the hydrology, geochemistry, and microbiology of taliks under lakes and ponds, defined as a layer or body of unfrozen ground in permafrost regions. These taliks are hydrologically connected to surface waters but are poorly understood due to long periods of extensive ice cover and inherent difficulty in accessing them. While permafrost creates an effective barrier that can isolate microbial communities within taliks, climate warming in the Arctic at twice the global mean is contributing to decreases in both the distribution and thickness of permafrost that will diminish these barriers and lead to talik expansion, which is of great concern when considering the microbial respiration of vast reserves of soil organic carbon in permafrost and associated methane release from thermokarst lakes. The Arctic is also experiencing dramatic hydrological and hydrogeological changes leading to a rapidly evolving interrelationship between surface waters and groundwaters. This is affecting the partitioning of water stored above and below ground and connectivity of surface waters with subsurface environments due to changing hydrologic flowpaths, and physicochemical conditions. These climate-related impacts will strongly influence talik environments, but the degree and extent of these impacts on microbial diversity and biogeochemistry and their subsequent future interconnectivity with surface waters are unknown. HQP-led projects will generate new knowledge about the extent and composition of taliks under lakes and ponds at three field sites in continuous and discontinuous permafrost regions. It will identify and map these taliks and their interconnectedness with other subsurface feature, measure and compare the thermal, hydrogeochemical, and microbial properties of these taliks, and determine how talik properties influence adjacent aqueous and sedimentary environments such as overlying waters or nearshore settings. HQP will conduct extensive fieldwork at these sites and become proficient in techniques in geophysics, geochemistry, metagenomics, and microscopy. In addition to new knowledge generated through the scientific work of 19 HQP, this program will directly benefit northern communities that are concerned about the impacts of climate warming on freshwater environments. In addition, Canadian citizens will directly benefit by having a better understanding of the Arctic terrestrial landscape through these efforts. Their knowledge will help society understand how climate warming is impacting the Arctic and will guide present and future policymakers in their determination for how Canada addresses global climate change. Finally, through the development of HQP-led projects that include 5 northern community members, this work will help to empower these communities to understand and prepare for future hydrological and geochemical changes as a result of climate warming.