Movement and spatial consumer-resource dynamics in a rapidly changing world

在过去的20年里，我们对影响动物运动过程的众多因素的理解取得了巨大的进步。较少关注气候变化和人为景观干扰对空间动态和种群生存能力的影响。我的长期目标是确定草食动物迁移的因果机制联系，确定如何运动有助于当地的消费者和他们的资源丰富的共同变化，消费者资源动态的空间过程的影响建模，并使用这些模拟模型来评估气候变化和人为干扰的影响迁移草食动物的生存能力。我建议解决这些目标，使用混合的理论和实地技术，在三个充分研究的生态系统中的迁徙草食动物种群：（1）角马和汤姆森的瞪羚在开放的平原和森林草原的塞伦盖蒂国家公园，（2）野生和驯养驯鹿在山区的斯堪的纳维亚半岛，（3）迁徙林地驯鹿在北方的森林中的北方安大略。实地研究将仅限于非洲和斯堪的纳维亚地区，因为已经获得了林地驯鹿的相关实地测量结果。理论建模将完全集成到所有3个生态系统中，并使用空间明确的模拟模型来探索运动和空间动态对生态相互作用的影响。 捕食风险将通过绘制整个景观中捕食者的利用分布图进行评估，并通过食草动物丰度的局部变化进行加权，因为风险通常与大多数捕食者功能反应中的局部猎物丰度呈负相关。能量效益将通过估计食草动物的饮食进行评估，无论是通过直接观察或从动物携带的摄像机连接到无线电项圈，结合标准的实验室测定可消化的能量从近似分析。能源成本将通过常规纳入GPS无线电项圈的加速度计进行评估，并根据行为观察进行校准。空间明确的代理为基础的模拟将被用来评估所观察到的运动轨迹的影响，通过整合风险，精力充沛的收益，精力充沛的成本在整个年度迁移周期。将使用多相状态空间模型对所有4个物种的观察到的运动轨迹进行建模，以估计转弯率、方向偏差和步长的组合，这些组合以当地景观特征、季节性和动机状态为条件。由此产生的运动模型将被纳入空间明确的代理人为基础的模拟模型，以评估人口生产力和长期生存能力的长期趋势与现实水平的环境随机性。

The past 2 decades has witnessed enormous advances in our understanding of the multitude of factors influencing animal movement processes. Less attention has been devoted to the impact of climate change and anthropogenic landscape disturbance on spatial dynamics and population viability. My long-term objectives are to identify causal mechanistic links for herbivore migration, determine how movement contributes to local co-variation in the abundance of consumers and their resources, model the impact of spatial processes on consumer-resource dynamics, and use those simulation models to evaluate the impact of climate change and anthropogenic disturbance on the viability of migratory herbivores. I propose to address these objective using a mix of theoretical and field techniques in three well-studied ecosystems populated by migratory herbivore populations: (1) wildebeest and Thomson's gazelles in the open plains and wooded grasslands of Serengeti National Park, (2) wild and domesticated reindeer in the montane regions of Scandinavia, and (3) migratory woodland caribou in the boreal forests of northern Ontario. Field studies will be restricted to just the African and Scandinavian sites, since the relevant field measurements have already been obtained for woodland caribou. Theoretical modeling will be fully integrated into all 3 ecosystems, with spatially-explicit simulation models used to explore the implications of movement and spatial dynamics for ecological interactions. Predation risk will be assessed by mapping the utilization distribution of predators across the landscape, weighted by local variation in herbivore abundance since risk is generally inversely related to local prey abundance in most predator functional responses. Energetic benefits will be assessed by estimating herbivore diet either by direct observation or from animal-borne video cameras attached to radio-collars, combined with standard lab assays of digestible energy from proximate analysis. Energetic costs will be assessed by accelerometers routinely incorporated into GPS radio-collars, calibrated against behavioral observations. Spatially-explicit agent-based simulations will be used to evaluate the impact of observed movement trajectories, by integrating risk, energetic gain, and energetic costs over the entire annual migratory cycle. The observed movement trajectories for all 4 species will be modeled using multiphasic state-space models to estimate combinations of turn rates, directional bias, and step lengths conditioned on local landscape features, seasonality, and motivational state. The resulting movement models will be incorporated into spatially-explicit agent-based simulation models to evaluate long-term trends for population productivity and long-term- viability in relation to realistic levels of environmental stochasticity.