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

快速变化的世界中的运动和空间消费者资源动态

• 批准号: RGPIN-2017-04395
• 负责人: Fryxell, John
• 金额: $ 2.4万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=651239
• 关键词: Movement; spatial; consumer; resource; dynamics

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.

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。气候变化和人为景观干扰对空间动态和种群生存力的影响研究较少。我的长期目标是确定食草动物迁徙的因果机制联系，确定运动如何促进消费者及其资源丰富度的局部共变，模拟空间过程对消费者-资源动态的影响，并使用这些模拟模型来评估气候变化和人为干扰对迁徙食草动物生存能力的影响。我建议在三个被充分研究过的由迁徙食草动物种群组成的生态系统中使用理论和实地技术来解决这些问题：(1)塞伦盖蒂国家公园开阔平原和树木繁茂的草原上的牛羚和汤姆逊瞪羚，(2)斯堪的纳维亚山区的野生和驯养驯鹿，(3)安大略省北部北方森林中迁徙的林地驯鹿。实地研究将仅限于非洲和斯堪的纳维亚的地点，因为已经获得了林地驯鹿的有关实地测量结果。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生态相互作用的运动和空间动力学的含义。******捕食风险将通过绘制捕食者在整个景观中的利用分布来评估，并通过草食动物丰度的当地变化来加权，因为在大多数捕食者功能响应中，风险通常与当地猎物丰度成反比。能量效益将通过直接观察或通过连接在无线电项圈上的动物传播的摄像机，结合来自近似分析的可消化能量的标准实验室分析，来评估食草动物的饮食。能量消耗将通过GPS无线电项圈中的加速度计进行评估，并根据行为观察进行校准。空间明确的基于主体的模拟将用于评估观察到的运动轨迹的影响，通过整合整个年度迁徙周期的风险、能量增益和能量成本。观察到的所有4种物种的运动轨迹将使用多相状态空间模型进行建模，以估计取决于当地景观特征、季节性和动机状态的转换率、方向偏差和步长的组合。由此产生的移动模型将被纳入空间明确的基于主体的模拟模型，以评估与现实环境随机性水平相关的人口生产力和长期生存能力的长期趋势。