Trophic interactions in a connected Arctic: an empirical and theoretical approach

我们生活在一个互联的世界里。与人类世界一样，由于营养物质、猎物和消费者跨越生态系统边界的移动，生态系统也在局部到全球范围内相互联系。这些联系目前正以前所未有的速度被人为活动破坏。例如，由于各种人为压力(如鲑鱼、鲸鱼)，连接生态系统的一些迁徙种群急剧减少，而由于农业集约化(如鹅)，其他迁徙种群呈指数增长。因此，生态学家面临着理解野生动物如何受到一种新的全球压力的影响的挑战，即人类对生态系统之间联系的改变。尽管已知其中一些改变已经造成了重大的生态和经济影响，但它们对野生动物的直接和连锁影响背后的机制在很大程度上仍未被探索。我的研究计划旨在更好地理解这些关键问题。与我的学生和同事一起，我们将确定来自其他生态系统的资源输入是否可以1)影响全球和环极尺度的营养相互作用，2)维持局部尺度的捕食者种群，以及3)影响局部和环极尺度的受保护物种。为此，我将领导致力于研究苔原生态系统物种群落的创新研究项目。我们将主要研究海洋资源的可获得性和北极捕食者的候鸟对消费者人口学和捕食者-猎物相互作用的影响。我们还将利用这一研究系统中发生的关键过程来开发理论模型，以预测生态系统之间的联系对物种相互作用的影响。这些模型将对广泛的研究系统感兴趣，因为来自其他生态系统的资源投入及其后果无处不在。通过我的研究项目获得的见解将对解决科学家和社会共同面临的问题具有实际意义。一些拟议的项目将调查最近维持北极捕食者种群的苔原筑巢鹅的激增是否有助于解释环极范围内滨鸟数量的普遍下降。解决这一保护问题可能需要北极居民对鹅施加更大的收获压力，而这些措施可以同时解决北方人目前面临的粮食安全问题。因此，我的研究计划将继续向加拿大和国外的政策制定者提供在全球压力下实施循证政策所需的知识。

We live in a connected world. Alike the anthropogenic world, ecosystems are also connected to each other at local to global scales due to movements of nutrients, prey and consumers across ecosystem boundaries. These connections are currently being disrupted by anthropogenic activities at an unprecedented rate. For instance, some migratory populations connecting ecosystems have sharply declined due to various anthropogenic pressures (e.g. salmons, whales), while others have increased exponentially as a result of agriculture intensification (e.g. geese). Ecologists thus face the challenge of understanding how wildlife is affected by a new global pressure, namely human-induced modifications in connections between ecosystems. Although some of these modifications are known to have induced major ecological and economic impacts, the mechanisms underlying their direct and cascading effects on wildlife are still largely unexplored. My research program will aim at better understanding these critical questions. With my students and colleagues, we will determine whether inputs of resources from other ecosystems can 1) impact trophic interactions at global and circumpolar scales, 2) sustain predator populations at a local scale, and 3) impact species of conservation concern at local and circumpolar scales. To do so, I will lead innovative research projects devoted at studying the community of species inhabiting tundra ecosystems. We will mainly look at the consequences of the availability of marine resources and of migratory birds for arctic predators on consumer demography and predator-prey interactions. We will also use key processes occurring in this study system to develop theoretical models to predict the impact of connections between ecosystems on species interactions. These models will be of interest for a broad range of study systems, because inputs of resources from other ecosystems and their consequences are ubiquitous. The insights gained through my research program will have practical implications to solve issues shared by both scientists and society. Some of the proposed projects will investigate whether the recent explosion of tundra-nesting geese, that sustain arctic predator populations, could contribute to explaining the somewhat general decline of shorebird populations at a circumpolar scale. Tackling this conservation issue may require increasing harvesting pressures on geese by residents of the Arctic, and such measures could simultaneously address the food security issues currently experienced by northerners. My research program will thus continue feeding policy makers, both in Canada and abroad, with the knowledge required to implement evidence-based policies in a world under global pressures.