Spatial ecology and predator-prey dynamics

大量的理论表明，大多数捕食者-被捕食者系统应该倾向于大量的极端循环，但这样的循环在自然界中是罕见的。一个合理的解释是，弱混合的捕食者和猎物产生异步变化，在当地的人口动态。我的长期目标是确定运动过程，空间分布模式和捕食者-猎物动态之间的因果机制联系。空间明确的模型和实验将被用来评估弱混合的程度，以稳定捕食者-猎物动态。我建议使用理论，现场和实验室的方法相结合来解决这个目标。拟议的实地工作扩展了我们正在进行的观察研究的行为和动态的一套大型食草动物和食肉动物在塞伦盖蒂国家公园。它基于复杂随机行走过程的计算机模型，遥感景观特征，卫星GPS无线电项圈，加速度计和动物安装的视频摄像机项圈的最新组合，即使动物不在视线范围内也能观察到行为。拟议的实验室工作响应一个令人兴奋的新机会，使用一个独一无二的设施在圭尔夫大学，称为Limnotron，实验测试运动过程如何有助于空间动态和食物网的相互作用在大规模水生生态系统的受控条件下。在这两种情况下，我们研究移动的人口的资源和他们的消费者的行为，喂养，运动和人口参数可以估计从个人的观察，然后相关的空间分布模式和人口动态测量在粗糙的时间和空间尺度。理论建模是很好地集成到现场和实验室程序，充分探索生态相互作用的运动和空间动态的影响。这些模型将帮助我们建立空间过程及其生态后果之间的概念联系。这是朝着确定在景观尺度上养护和管理复杂自然生态系统的最佳手段迈出的重要一步。

A large body of theory suggests that most predator-prey systems should be prone to extreme cycles in abundance, yet such cycles are rare in nature. One plausible explanation for this paradox is that weak mixing of predators and prey produces asynchronous variation in local population dynamics. My long-term objective is to identify causal mechanistic links between movement processes, patterns of spatial distribution, and predator-prey dynamics. Spatially-explicit models and experimental trials will be used to evaluate the degree to which weak mixing serves to stabilize predator-prey dynamics. I propose to address this objective using a combination of theoretical, field and laboratory approaches. The proposed field work extends our ongoing observational studies of behavior and dynamics of a suite of large herbivores and carnivores in Serengeti National Park. It is based on a state-of-the-art combination of computer models of complex random walk processes, remotely-sensed landscape features, satellite GPS radio-collars, accelerometers, and animal-mounted video camera-collars to observe behavior even when animals are out of sight. The proposed laboratory work responds to an exciting new opportunity to use a one-of-a-kind facility at the University of Guelph, called the Limnotron, to test experimentally how movement processes contribute to spatial dynamics and food-web interactions under controlled conditions in massive aquatic mesocosms. In both cases, we study mobile populations of resources and their consumers whose behavior, feeding, movement, and demographic parameters can be estimated from observations of individuals, which are then related to spatial distribution patterns and population dynamics measured at coarser temporal and spatial scales. Theoretical modeling is well-integrated into both the field and laboratory programs, to fully explore the implications of movement and spatial dynamics for ecological interactions. These models will help us to forge conceptual links between spatial processes and their ecological consequences. This is an important step towards identifying the best means of conserving and managing complex natural ecosystems at a landscape scale.