Bottom-up and top-down effects on natural selection, evolution, and population dynamics of boreal mammals

加拿大的北方森林，像世界上许多地方一样，由于人类侵略性的土地利用和气候变化，正在经历前所未有的变化。生态学家面临的挑战是为社会提供这个生态系统未来会是什么样子的答案。要做到这一点，我们需要了解环境变化对自然选择、种群动态和物种相互作用的影响。我一直在育空克卢恩湖（Kluane Lake Yukon）的北方森林工作，以了解红松鼠和雪鞋兔这两种食草动物是如何应对食物供应、自身密度以及捕食它们的捕食者的变化的。Kluane红松鼠项目（KRSP）收集了跨越12代30年的15,000只红松鼠的表型和健康信息。我们利用这些信息来理解个体内部（可塑性）、个体之间（选择）和世代之间（微进化）对重要环境和生物驱动因素的反应。我将利用红松鼠的领土特性来衡量个体资源的可用性（领土质量），并将其与个体的领土选择、幼崽的生存和适合度联系起来。这项工作将填补个体差异的生态和进化后果研究中的一个主要空白。许多关于气候变化对物种的潜在影响的研究都集中在物候（时间）反应上，就像我们对红松鼠所做的那样。然而，由于生物相互作用的复杂性，特别是捕食者-猎物动态，预测气候变化对物种人口统计的影响仍然具有挑战性。在北方森林中，这意味着我们需要了解气候变化如何影响雪鞋兔-猞猁的循环。我们正在进行的监测已经产生了一个跨越40年和5个高峰的数据库，为探索气候变化如何影响这种标志性的捕食者-猎物动态提供了必要的背景。我将利用生物记录技术的进步来研究野兔食物供应和捕食者（消耗性和非消耗性影响）对野兔人口的详细互动影响，并解决气候变化改变经典野兔-猞猁周期的可能性。

Canada's boreal forest, like many parts of the world, is undergoing unprecedented change due to aggressive human landuse and climate change. The challenge for ecologists is to provide society with answers to the question of what this ecosystem will look like in the future. To do so we need to understand the effects of environmental change on natural selection, population dynamics, and species interactions. I have been working in the boreal forest at Kluane Lake Yukon to understand how two herbivores, red squirrels and snowshoe hares, respond to changes in their food supply, their own densities, and the predators that consume them. The Kluane Red Squirrel Project (KRSP) has amassed phenotype and fitness information for 15,000 individual red squirrels spanning 12 generations and 30 years. We use this information to understand within individual (plasticity), between individual (selection), and between generation (microevolution) responses to important environmental and biotic drivers. I will take advantage of the territorial nature of red squirrels to measure individual resource availability (territory quality) and link this to individual territory selection, juvenile survival, and fitness. This work will fill a major gap in the study of the ecological and evolutionary consequences of individual differences. Many of the studies of potential climate change effects on species have focused on phenological (timing) responses as we have done with red squirrels. Forecasting impacts of climate change on species demography, however, remains challenging due to the complexities associated with biotic interactions and in particular, predator-prey dynamics. In the boreal forest this means we need to understand how climate change might affect the snowshoe hare-lynx cycle. Our ongoing monitoring has produced a database spanning 40 years and 5 hare peaks which provides the necessary backdrop to explore how climate change might affect this iconic predator-prey dynamic. I will take advantage of advances in bio-logging technology to examine the detailed interactive effects of hare food supply and predators (consumptive and non-consumptive effects) on hare demography and address the potential for climate change to alter the classic hare-lynx cycle.