Dissertation Research: The Role of Habitat Selection Behavior in Mediating Trophic Interactions

了解消费者如何在栖息地中进行选择，对于预测群落层面对捕食者和资源操纵的反应至关重要。目前的模型预测了不同栖息地的死亡风险和摄食率不同时的个体栖息地选择，但没有纳入动态资源。这项研究将扩展这些模型以包括资源动态，显示消费者在栖息地的分布如何取决于死亡风险和资源生产率。具体地说，将在简单的两个栖息地实验系统中测试消费者和资源对捕食者和养分操纵的反应。在这些系统中，小蓝鲨(Lepomis Macchirus)可以在成对的实验池塘之间自由移动，但它们的捕食者--大口黑鱼(Micropterus Salmoides)--被限制在特定的池塘中。这些池塘还包含自给自足的浮游动物种群(蓝鳍金枪鱼的资源)。研究将解决以下具体问题：1)在消费者可以在具有不同死亡风险和自我更新资源的栖息地之间进行选择的情况下，消费者是否最优地使用栖息地；2)每个栖息地的消费人口比例如何随着资源生产率的不同而变化，消费者栖息地选择对栖息地内资源动态有何影响？这些研究首次对将栖息地选择行为与其对社区动态的影响联系起来的理论进行了实证检验。

An understanding of how consumers choose among habitats is essential to predicting community level responses to predator and resource manipulations. Current models predict individual habitat choice when mortality risk and feeding rates vary among habitats, but do not incorporate dynamic resources. This study will extend these models to include resource dynamics, showing how the distribution of consumers among habitats is dependent on mortality risk and resource productivity. Specifically, the response of consumers and resources to predator and nutrient manipulations in simple, two habitat, experimental systems will be tested. In these systems, small bluegills (Lepomis macrochirus) are free to move between paired experimental pools, but their predators, largemouth bass (Micropterus salmoides) are confined to specific pools. These pools also contain self-supporting populations of zooplankton (the bluegill's resource). The research will address the following specific questions: 1) Under the situation where consumers can choose among habitats with differing mortality risks and self-renewing resources, do consumers use habitats optimally, 2) How does the portion of the consumer population in each habitat vary with varying resource productivity, and 3) What are the consequences of consumer habitat choice to resource dynamics within habitats? These studies provide the first empirical test of theory linking the behavior of habitat selection to its consequences for community dynamics.