Dynamics and stability of freshwater resource-consumer systems: testing mechanisms from structured theory

关于生物种群动态的生态学理论是一个强大的工具，我们可以用它来解释在各种生态环境中物种丰度随时间和空间的变化。通常，这种理解可以用来解决有关疾病或病原体传播、物种种群保护或资源管理的重要应用问题。我研究的主要目标是发展这一理论，并测试我们在不同环境中解释生物种群动态的基本特性（例如，有无周期、不规则波动或种群稳定性）的能力。淡水藻类-草食动物系统是这个企业的理想选择。我们有大量关于个体的生理、行为和生活史的定量信息，我们可以用这些信息来构建它们动态相互作用的结构化种群模型。我们可以在简单的群落中进行操纵实验，以严格测试导致不同类型种群动态的一般机制。最后，我们可以通过改变食物网结构或空间变化来增加生态复杂性，并测试我们在更现实的条件下捕捉动态的能力。在我提出的研究中，我评估了(1)淡水消费者生活史的一般特征是否决定了我们在许多系统中观察到的种群动态类型，(2)耦合或解耦藻-草食相互作用的元素的再循环是否可能在资源-消费者相互作用的稳定性中发挥关键作用，以及(3)我们对种群过程(生长，扩散，和平流)可以解释空间模式是如何随着时间的推移在藻类食草系统中出现和演变的。

Ecological theory on the dynamics of biological populations is a powerful tool that we can use to explain variation in the abundance of species over time and space in a variety of ecological settings.  Often this understanding can be used to solve important applied problems concerning spread of diseases or pathogens, conservation of species populations, or management of resources. The major goal of my research is to develop this theory and test our ability to explain fundamental properties of the dynamics of biological populations (e.g. presence or absence of cycles, irregular fluctuations, or population stability) in different environments.Freshwater algal-herbivore systems are ideal for this enterprise.  We have extensive quantitative information on the physiology, behaviour, and life-history of individuals that we can use to construct structured population models for their dynamic interactions.  We can perform manipulation experiments in simple communities to test rigorously general mechanisms causing different types of population dynamics.  Finally, we can add ecological complexity by modifying food-web structure or spatial variability and test our ability to capture the dynamics under more realistic conditions.In my proposed research, I evaluate (1) whether general features in the life-history of freshwater consumers determine the type of population dynamics that we observe in many systems, (2) whether recycling of elements that act to couple or decouple algal-herbivore interactions may play a key role in stability of the resource-consumer interaction, and (3) whether our understanding of population processes (growth, dispersal, and advection) can explain how spatial patterns emerge and evolve over time in algal-grazer systems.