A multi-Consumer Perspective of Consumer-Resource Dynamics

提案号：deb01-29270提案标题：消费者资源动态的多物种视角名称：Priyanga AmarasekareInstitution: University of Chicago本研究调查了多种捕食者和寄生虫物种如何影响其共同猎物或宿主物种的动态（丰度变化）。研究的重点生态系统是加利福尼亚南部的小丑虫和两种类寄生虫（寄生在其他昆虫身上并杀死其他昆虫的寄生虫），它们会攻击小丑虫的卵。该系统提出了一个难题：多个拟寄生物可以在同一寄主阶段共存，并减少寄主丰度的波动。解决这一难题需要了解两种拟寄生物在单一寄主物种上共存的机制，以及这些机制如何反过来影响拟寄生物对寄主的影响。第一个目标是区分寄生蜂共存机制的两种假说，即寄生蜂内部捕食（IGP）和时间生态位划分（TNP）。种群内捕食预示着物种会共存，因为一个物种更擅长攻击未寄生的宿主，而另一个物种更擅长攻击已被前者寄生的宿主（多重寄生）。时间生态位划分预测物种将共存，因为每个物种在一年中的不同时间都更擅长攻击宿主。这两种假设的预测将通过可操作的现场实验进行检验。了解共存的拟寄生物物种如何影响宿主种群动态，将是探索不同共存机制（IGP vs. TNP）下拟寄生物对宿主丰度和变异性影响的数学模型领域。这项研究是新颖的，因为它调查了多个消费物种如何影响共享资源的动态，这是一个鲜为人知的问题，对物种多样性的维持至关重要。具有一定的应用意义。决定释放一种或多种天敌来控制一种害虫，这是害虫生物防治的核心问题，关键取决于天敌在特定害虫物种上共存的机制。将资源利用机制与种群动态联系起来，使我们能够预测哪种天敌组合能最有效地控制害虫。

Proposal Number: DEB-01-29270Proposal Title: A multi-species perspective of consumer-resource dynamicsPI Name: Priyanga AmarasekareInstitution: University of Chicago This research investigates how multiple predator and parasite species influence the dynamics (change in abundance) of their common prey or host species. The ecological system that is the focus of research is the harlequin bug and two parasitoid species (parasitic insects that grow on and kill other insects) that attack the bug's eggs in southern California. The system presents a puzzle: multiple parasitoid species can coexist on the same host stage as well as reduce fluctuations in host abundance. Solving the puzzle requires understanding the mechanism(s) by which both parasitoid species coexist on a single host species, and how these mechanism(s) in turn influence the parasitoids' effect on the host. The first goal is to distinguish between two hypotheses that address mechanisms of parasitoid coexistence are intraguild predation (IGP) and temporal niche partitioning (TNP). Intraguild predation predicts that species will coexist because one species is superior at attacking unparasitized hosts while the other species is superior at attacking hosts already parasitized by the first (multiparasitism). Temporal niche partitioning predicts that species will coexist because each is superior at attacking hosts at different times of the year. Predictions for the two hypotheses will be tested via manipulative field experiments. Understanding how coexisting parasitoid species influence host population dynamics will be the domain of mathematical models that explore the impact of parasitoids on host abundance and variability under different mechanisms of coexistence (IGP vs. TNP). This research is novel because it investigates how multiple consumer species influence the dynamics of a shared resource, a poorly understood issue that is critical to the maintenance of species diversity. It also has applied significance. The decision to release single or multiple natural enemies to control a pest, an issue at the heart of biological pest control, depends crucially on the mechanisms by which natural enemies coexist on a given pest species. Linking mechanisms of resource use with population dynamics allows us to predict which combinations of natural enemies provide the most effective control of a pest.