DISSERTATION RESEARCH: The Impact of Specialist Insect Herbivores on Plant Community Composition.

自然植物群落中不同物种的相对丰度受到植物物种间竞争的结果和食草性的影响，但我们对这些力量在自然系统中如何相互作用缺乏一般的了解。近年来，越来越清楚的是，物种的空间组织对物种之间的相互作用有着深远的影响。陆生植物的不动性使植物竞争成为一个高度局域化的过程。然而，移动食草动物造成的损害发生在区域范围内。我将使用空间明确的数学模型，结合实地实验，研究这些局部和区域过程之间的相互作用，以确定植物物种在其自然栖息地的组成和相对丰度。已知黄花甲虫（Trirhabda属）达到极高的种群密度，并摧毁其寄主植物高黄花（Solidago altissima）。因此，这种强烈的食草性极大地减少了对其他植物物种的竞争压力，导致其丰度发生了巨大的变化。我将使用Trirhabda-Solidago系统的数据来测试我的空间模型解释自然植物种群丰度模式的能力。这项工作将包括对空间尺度在形成物种相互作用中的作用的独特检查。通过将空间生态模型和野外数据结合起来，我的研究将促进数学方法的发展，这些方法可以广泛应用于环境科学。

The relative abundances of different species in natural plant communities is influenced by the outcome of competition among plant species and by herbivory, yet we lack a general understanding of how these forces interact in natural systems. In recent years, it has become increasingly clear that the spatial organization of species has a profound impact on how those species interact. The immobile nature of terrestrial plants makes plant competition a highly localized process. Damage by mobile herbivores, however, occurs over a regional scale. I will use spatially-explicit mathematical models, in conjunction with field experiments, to investigate the interplay between these local and regional processes in determining the composition and relative abundances of plant species in their natural habitats. The goldenrod beetle (genus Trirhabda) is known to reach extremely high population densities and to decimate its host plant, tall goldenrod (Solidago altissima). S. altissima is a competitive dominant, so this intense herbivory substantially reduces the competitive stress on other plant species, leading to dramatic changes in their abundances. I will use data on the Trirhabda-Solidago system to test the ability of my spatial models to explain patterns of abundances in natural plant populations. This work will comprise a unique examination of the role of spatial scale in shaping species interactions. By bringing together spatial ecological models and field data, my research will foster the development of mathematical methods that can be widely applied in the environmental sciences.