Dissertation Research: The Influence of Immigration on Local Community Structure: Experimental Tests of Theory in Two Beetle Communities

确定当地社区的结构机制是社区生态学的一个基本目标。从历史上看，生态学家援引当地的过程来解释社区结构，但模棱两可的证据扩大了辩论，包括区域过程在构建社区的潜在重要性。虽然实验已被证明是解决生态学问题的关键，但迄今为止，理论和观测研究一直是用来研究区域过程影响的主要工具。我提出了一系列新颖的实验，以测试跨越本地和区域多样性控制之间的理论。本地过程，集合种群竞争和中性社区理论对移民的影响进行了预测，这些预测在性质上是不同的，相互排斥的，并且可以在相同的移民实验中进行测试。本论文将利用拟谷盗的实验室系统和切蝇属叶柄甲虫的田间系统，通过对迁入状态和相互作用强度（实验室）、迁入暴露量和离定殖源的距离（田间）的控制，对上述理论进行实验验证。虽然最近发展的理论认为区域过程可以对群落结构产生主导作用，但如果要从区域过程的角度来理解群落生态学，必须首先从实证上证实这一理论。

Identifying the mechanisms that structure local communities is a fundamental goal of communityecology. Historically, ecologists invoked local processes to explain community structure, butequivocal evidence has broadened debate to include the potential importance of regionalprocesses in structuring communities. Though experimentation has proven critical in resolvingissues in ecology, theoretical and observational studies have, thus far, been the primary tools usedto examine the effects of regional processes. I propose a series of novel experiments to testtheories that span the range between local and regional control of diversity. Local process,metapopulation competition, and neutral community theories make predictions about the effectsof immigration that are qualitatively different, mutually exclusive, and testable in the sameimmigration experiments. Using a laboratory system of Tribolium flour beetles and a field systemof Cecropia petiole beetles, I will experimentally test these theories by simultaneouslymanipulating immigration regime and interaction strength (lab), and exposure to immigration anddistance from colonization source (field). Though recently developed theory suggests regionalprocesses can have a dominant effect on community structure, the theory must first be confirmedempirically if community ecology is to gain insight from the regional process perspective.