Climate change and vulnerability of the sub-arctic ecosystem near Hudson Bay

气候变化对北极生物多样性的保护构成了重大挑战。全球变暖可以破坏营养关系，改变复杂的物种相互作用，包括栖息地、捕食者-猎物关系、竞争和物种分布的变化。需要量化影响北方生态系统变化的机制，以了解北极生物多样性可能如何得到保护。种群可能对范围边缘的环境驱动因素最敏感，我的研究将通过对物种-环境分布的前沿和尾部边缘的研究，提高对北方生态系统变化机制的理解。为了满足这一需求，我的研究项目在哈德逊湾低地进行，这是一片具有全球意义的湿地，重叠着连续不断的永久冻土和几种适应北极的野生动物的南部范围界限。我们将使用短期研究和长期数据集的组合来测试关于物种-环境相互作用所介导的生态系统变化驱动因素的假设。三个重点领域将支持我们的研究目标：1)测试气候变化是否通过对永久冻土的相互作用影响野生动物栖息地的可用性和质量；2)测试气候、捕食和栖息地条件对亚北极系统中等营养水平的相对重要性，特别是滨鸟和水禽的巢址选择和繁殖生态；3)测试关于气候变暖和涉及竞争的前沿动态是否影响北极狐在亚北极生态系统中的脆弱性和功能作用的假设。目标1将利用地面测量和遥感技术来描述季节性天气模式、永久冻土动态(例如活动层深度)、湿地水文和植被结构之间的相互作用造成的栖息地变化。目标-2将重点研究水鸟(加拿大鹅和滨鸟)的巢址选择和繁殖成功与捕食、气候和与栖息地条件的相互作用的关系(由目标-1提供信息)。目标-3将侧重于北极狐作为关键指示物种的作用，它既影响生态系统中的其他营养水平，也受到其他营养水平的影响。我的研究计划将全面评估环境变化如何影响处于分布边缘的北极物种，帮助澄清一般机制，预测未来趋势，并为资源管理决策提供信息。我的研究计划包括对15名HQP(5名研究生和10名本科生暑期学生)的培训，并将使学生获得实地研究、先进技术(如遥感)和北极生态学理论知识的技能。HQP将参加一个由学术界、土著社区和政府参与的团队设置，涉及将科学应用于可持续资源管理。

Climate change poses a significant conservation challenge to arctic biodiversity. Global warming can disrupt trophic relationships and alter complex species interactions, including changes to habitat, predator-prey relationships, competition, and species distributions. Quantifying the mechanisms affecting change in northern ecosystems is needed to understand how arctic biodiversity may be conserved. Populations may be most sensitive to environmental drivers at the edge of range and my research will improve understanding of the mechanisms of change in northern ecosystems through studies at the leading and trailing edges of species-environmental distributions. To address this need, my research program operates in the Hudson Bay Lowlands, a globally significant wetland overlapping the southern range limit of continuous permafrost and several arctic adapted wildlife. We will use a combination of short-term studies and long-term datasets to test hypotheses regarding drivers of ecosystem change mediated by species-environment interactions. Three focal areas will support our research goals: 1) to test whether climate change affects the availability and quality of wildlife habitat through interacting effects on permafrost; 2) to test the relative importance of climate, predation, and habitat condition to affect intermediate trophic levels in the sub-arctic system, specifically nest-site selection and breeding ecology of shorebirds and waterfowl; and 3) test hypotheses as to whether climate warming and leading-trailing edge dynamics involving competition affect the vulnerability and functional role of arctic fox in the sub-arctic ecosystem. Objective-1 will employ ground measurements and remote sensing technology to characterize changes in habitat caused by interactions among seasonal weather patterns, permafrost dynamics (e.g. active layer depth), wetland hydrology and vegetation structure. Objective-2 will focus on studies of water bird (Canada geese and shorebirds) nest site selection and breeding success in relation to predation, climate and interactions with habitat condition (informed by Objective-1). Objective-3 will focus on the role of the arctic fox as a key indicator species that is both influential and affected by other trophic levels in the ecosystem. My research program will provide a comprehensive assessment of how environmental change impacts arctic species at the edge of their distributions, helping to clarify general mechanisms, anticipate future trends, and inform resource management decisions. My research program includes training for 15 HQP (5 graduate students and 10 undergraduate summer students) and will allow students to gain skills in field studies, advanced technologies (e.g. remote sensing), and theoretical knowledge in arctic ecology. HQP will participate in a team setting involving academia, indigenous communities, and government involving application of science to sustainable resource management.