Climate change consequences for an Arctic apex predator: polar bears as ecological indicators

随着气候变暖，冰盖覆盖的北极海洋生态系统正在经历快速的生态变化。影响北极熊(Ursus Maritimus)的海冰特征、初级生产力和生态系统结构方面的影响是显著的，北极熊是海冰特有的物种。这一建议的主要工作假设是，北极熊生态和生物标志物的变化与气候变暖导致的海冰栖息地改变导致的生态结构和物候变化有关。其目标是开发新的监测指标，记录气候变化对北极熊的后果，预测未来的变化，并研究北极熊与猎物和食腐动物的生态相互作用。目标包括确定与北极熊种群随时间变化相关的机制，以预测全球变暖的影响。在主要研究种群(即波弗特海、西哈德逊湾)进行长期采样，可以调查与不断变化的环境条件有关的空间动态、栖息地利用和种群动态。在接下来的五年里，我的研究小组将研究：使用遥感来评估北极熊的栖息地利用与生活史参数的关系，开发跨学科的方法来评估生活史事件和组织微观分析的压力，使用综合生活史和能量学模型来探索北极熊的未来状况，并研究北极熊的捕食者-猎物动态以及北极熊作为基石捕食者的作用。方法包括：卫星遥测、遥感、生物标志物、生态系统动力学、数学模型和遥感相机。该项目的重点是整合各种方法，以获得比单一技术更多的洞察力。与加拿大环境和气候变化以及渔业和海洋的伙伴关系提高了效率和样本规模。物种对全球变暖的反应是生态学家和管理者的根本兴趣，但对这种变化的机制和预测却知之甚少。对导致个体和种群反应的过程的机械理解对于预测一个物种的未来状况是必要的。方法的整合将提供新的见解。作为气候变化的旗舰物种，北极熊受到了当地、国家和国际的极大关注。

Ice-covered Arctic marine ecosystems are undergoing rapid ecological change as the climate warms. The effects are notable in sea ice characteristics, primary productivity, and ecosystem structure that affect polar bears (Ursus maritimus) which are a sea ice obligate species. The main working hypothesis of this proposal is that changes in the ecology and biomarkers of polar bears are associated with shifts in ecosystem structure and phenology caused by warming induced alteration of sea ice habitat. The objectives are to develop new monitoring metrics, document the consequences of climate change on polar bears, predict future changes, and examine the ecological interactions of polar bears with prey and scavengers. Objectives include identification of the mechanisms associated with polar bear population change over time to predict the effects of global warming. Long-term sampling in the key research populations (i.e., Beaufort Sea, Western Hudson Bay) allows investigation of the spatial dynamics, habitat use, and population dynamics in relation to changing environmental conditions. Over the next five years, my research group will examine: the spatial ecology and habitat use of polar bears using remote sensing to assess habitat use relationships with life history parameters, develop interdisciplinary means of assessing life history events and stress from microanalysis of tissues, use integrated life history and energetics modelling to explore the future status of polar bears, and examine the predator-prey dynamics of polar bears and the role of the bears as a keystone predator. Methods include: satellite telemetry, remote sensing, biomarkers, ecosystem dynamics, mathematical modelling, and remote cameras. The focus of the project is to integrate methods to obtain greater insight than possible from a single technique. Partnerships with Environment and Climate Change Canada and Fisheries and Oceans increase efficiency and samples sizes. Species responses to global warming are of fundamental interest to ecologists and managers yet the mechanisms of change and predictions for such changes are poorly understood. A mechanistic understanding of the processes that result in both individual and population response is necessary for predicting future conditions for a species. Integration of methods will provide novel insights. As a flagship species of climate change, polar bears have great local, national, and international interest.