Contingency and the Impact of Ecosystem Engineers: The Role of Plant Traits

虽然所有物种都以某种方式改变它们的栖息地，但“生态系统工程师”对相关物种的影响只有少数社区被量化。 本提案的目标是量化植物结构与叶质量的影响，叶绑毛虫（工程师）对相关的节肢动物区系的各种橡树（栎属）物种的相对影响。在形成叶结，这些毛毛虫工程师一个独特的栖息地，随后由其他食草动物物种，捕食者，寄生虫，和食草动物殖民。通过将观察与实验相结合，调查人员将测试1）工程师对社区的影响是否取决于工程师本身对栖息地的适合性，2）工程效应的大小取决于工程栖息地的质量，第三章工程师对相关群落物种丰富度的影响取决于受到积极影响的物种的相对数量工程师的活动，和4）总节肢动物物种丰富度取决于之间的相互作用通才捕食者，物种，专门对叶结，和物种，避免叶结。这项研究将是第一个量化的条件，确定生态系统工程师对相关物种的影响，它将增加我们有限的了解无脊椎动物食草动物对其相关的节肢动物物种的影响，通过宿主植物介导。这项研究也将是第一个量化叶片质量和结构对节肢动物群落结构的相对重要性。这项研究将阐明昆虫在森林生态系统中的作用及其对森林生产力的影响。此外，它将确定植物的性状，可能提供抵抗最初的攻击叶绑毛虫。在节肢动物物种的自然历史上获得的信息将被用于未来为林业工作者，教育工作者和生态学家开发的插图指南。博物馆将加强对小鳞翅目昆虫及其寄生虫的收藏。最后，这项研究将培养一名博士后研究助理，一名研究生，和一些本科生在基础生态学和实地研究方法。

Although all species modify their habitat in some fashion, the impact that 'ecosystem engineers' have on associated species has been quantified in only a few communities. The goal of this proposal is to quantify the relative influence of plant architecture versus leaf quality on the impact that leaf-tying caterpillars (engineers) have on the associated arthropod fauna of various oak (Quercus) species. In forming leaf ties, these caterpillars engineer a unique habitat that is colonized subsequently by other herbivore species, predators, parasitoids, and detritivores. By combining observation with experimentation, the investigator will test whether 1) the impact of engineers on a community depends on the suitability of the habitat for the engineer itself, 2) the magnitude of the engineering effect depends on the quality of the habitat engineered, 3) the impact of the engineer on species richness of the associated community depends on the relative number of species that are positively affected by the activities of the engineer, and 4) total arthropod species richness depends on interactions among generalist predators, species that specialize on leaf ties, and species that avoid leaf ties. This study will be one of the first to quantify the conditions that determine the impact an ecosystem engineer has on associated species and it will add to our limited understanding of the effects of invertebrate herbivores on their associated arthropod species, mediated through the host plant. The study will also be the first to quantify the relative importance of leaf quality and architecture for arthropod community structure. This study will clarify the role that insects play in forested ecosystems and their impact on forest productivity. In addition, it will identify plant traits that may provide resistance to initial attack by leaf-tying caterpillars. Information gained on the natural history of the arthropod species will be used in future illustrated guides developed for foresters, educators, and ecologists. Museum collections will be enhanced, both of the microlepidoptera and their parasitoids. Finally, the study will train a postdoctoral research associate, one graduate student, and a number of undergraduates in basic ecology and field research methods.