A multi-Consumer Perspective of Consumer-Resource Dynamics

提案编号：Deb-01-29270提案标题：消费者资源动态的多物种视角PI名称：Priyanga Amarasekare研究所：芝加哥大学这项研究调查了多种捕食者和寄生虫物种如何影响其常见猎物或宿主物种的动态(丰度变化)。作为研究重点的生态系统是小丑虫和两种寄生物种(生长在上面并杀死其他昆虫的寄生昆虫)，它们攻击南加州的小丑虫卵。该系统提出了一个难题：多个寄生蜂物种可以共存于同一寄主阶段，并减少寄主丰度的波动。解开这个谜团需要了解两种寄生蜂物种共存于单一寄主物种的机制(S)，以及这些机制(S)如何反过来影响寄生蜂对寄主的影响。第一个目标是区分解决寄生蜂共存机制的两个假说：公会内捕食(IGP)和时间生态位分配(TNP)。行内捕食预测物种将共存，因为一个物种在攻击未被寄生的宿主方面占优势，而另一个物种在攻击已经被第一个寄生的宿主(多寄生性)时优势。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攻击宿主方面都具有优势。对这两个假设的预测将通过操纵性的现场实验进行验证。了解寄生寄生蜂物种如何影响寄主种群动态将是探索不同共存机制(IGP和TNP)下寄主丰度和变异性的数学模型的领域。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，这是一个对维持物种多样性至关重要的鲜为人知的问题。同时也具有一定的应用意义。决定释放单个或多个天敌来控制害虫，这是生物害虫控制的核心问题，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，使我们能够预测哪些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.