Net ecosystem exchange of carbon greenhouse gases in high Arctic ecoregions

人类活动使全球大气中温室气体(GHGs)、二氧化碳(CO2)和甲烷(CH4)的浓度上升到一定程度，导致地球气候系统明显和前所未有地变暖。在北极高地地区尤其如此，在过去的一个世纪里，那里的年平均气温上升速度几乎是全球的两倍。在北极高地的极地沙漠地区，如果冻土带植被在沙漠生态系统中定居，以应对日益加剧的气候变暖，则可以通过初级生产将大量二氧化碳从大气中隔离出来。相比之下，在土壤中有机碳储量较大的地区，永久冻土退化导致的土壤活动增加可能会导致二氧化碳和甲烷分解和释放到大气中的增加，从而对全球气候变暖产生积极的反馈作用。我们提议量化气候变化对埃尔斯米尔岛库蒂尼尔帕克国家公园陆地和水生景观中二氧化碳和甲烷净交换的影响，以确定该地区目前是处于净初级生产力阶段还是净分解阶段，未来变暖是否会导致温室气体对大气的正反馈或负反馈，以及北极生态系统将在未来气候变化的轨迹中发挥什么作用。然而，在加拿大北极高地进行研究的成本过高。我的学生每年仅执行拟议的研究项目的旅行成本(例如，埃德蒙顿/决心湾的往返航班、地点的生活费用以及包括运费在内的物流成本)就约为40,000美元。因此，NSERC的任何资金，如果能够增加这些高昂的旅行成本，反过来又可以腾出资金用于HQP的研究和进一步培训的直接成本。此外，我们希望获得额外的补充资金，以参加研讨会，向受气候变化影响的北方社区介绍我们的研究结果，并促进关于我们未来研究方向的科学和社会讨论。

Human activities have elevated global atmospheric concentrations of the greenhouse gases (GHGs) carbon dioxide (CO2) and methane (CH4) to levels that have resulted in an unequivocal and unprecedented warming of the Earth's climate system. This is especially true in the high Arctic, where in the past century average annual temperatures have increased at almost twice the global rate. In polar desert regions of the high Arctic, large amounts of CO2 could be sequestered from the atmosphere through primary production if tundra vegetation colonizes the desert ecosystem in response to increased warming. In contrast, in regions with large stores of organic carbon in soil, the increased soil activity that will result from permafrost degradation may cause increased decomposition and release of CO2 and CH4 into the atmosphere, positively feeding back on global climate warming. We are proposing to quantify the impacts of climate change on the net exchange of CO2 and CH4 from both terrestrial and aquatic landscapes in Quttinirpaaq National Park, Ellesmere Island, to determine if this region is currently in a phase of net primary productivity or net decomposition, whether future warming will result in positive or negative feedbacks of GHGs to the atmosphere, and what role Arctic ecosystems will play in future trajectories of climate change. However, the costs of conducting research in the Canadian high Arctic are exorbitant. The costs of travel alone for my students to carry out the proposed research program (e.g., return flights Edmonton/Resolute Bay, subsistence at sites, and logistic costs including shipping freight) approximate $40,000 annually. Therefore, any NSERC funding that can augment these high travel costs will in turn free up funds for the direct costs of research and further training of HQP. Furthermore, we wish to ask for additional supplementary funding to attend symposiums to present our findings to communities in the north that are affected by climate change, and foster scientific and social discussion about future directions of our research.