DISSERTATION RESEARCH: An Experimental Test of the Role of Keystone Processes in a Cavity-Nesting Bird Community

群落结构是指生态群落内物种的类型和数量，有时可以由对群落内关键过程施加异常强烈影响的单个物种驱动，例如通过改变生境。对这类生态系统过程的更好理解，可以帮助我们建立一个框架，预测物种灭绝或环境变化对群落结构的影响。在树洞筑巢的物种通常是高度结构化的系统，因为许多树洞筑巢的物种依赖于其他物种来创造它们使用的洞。洞巢脊椎动物是许多森林群落的主要组成部分，因此可以作为更好地了解生态过程、物种相互作用和由此产生的群落结构的良好模型系统。本研究考察了长叶松洞巢鸟类群落的两个生态过程，即洞的形成和洞的扩大，以及它们在结构中的作用。在长叶松洞巢鸟类群落中，濒危的红冠啄木鸟创造了27种其他物种使用的洞。本研究将利用四年的野外数据、实验操作的空穴可用性和统计模型来研究红冠啄木鸟空穴的形成和扩大对其他鸟类空穴巢的丰度的影响。通过研究广泛使用的濒危物种管理技术对一组非目标群落成员的潜在影响，研究结果将有助于理论生态学和保护生物学。这项研究将支持博士候选人的论文研究，并通过为计划参加研究生院的近期大学毕业生提供实地经验，包含强大的培训组成部分。

Community structure refers to the types and number of species within an ecological community and can sometimes be driven by an individual species that exerts an unusually strong influence on key processes within the community, for example by modifying habitat. A better understanding of such ecosystem processes could enable the development of a framework for predicting such things as the impact of the extinction of a species or environmental change on community structure. Communities in which species nest in tree cavities are often highly structured systems, as many cavity-nesters depend on other species to create the cavities they use. Cavity-nesting vertebrates comprise a major component of many forest communities and thus could be good model systems for better understanding ecological processes, species interactions and resulting community structure. This study examines two ecological processes, cavity creation and cavity enlargement, and the role they play in structuring the longleaf pine cavity-nesting bird community, in which the endangered red-cockaded woodpecker creates cavities used by 27 other species. This study will examine the impacts of red-cockaded woodpecker cavity creation and enlargement on the abundance of other avian cavity-nesters using four years of field data, experimental manipulation of cavity availability and statistical modeling. Study results will contribute to theoretical ecology, as well as conservation biology by examining the potential impacts of widely used endangered species management techniques on a suite of non-targeted community members. This study will support the dissertation research of a doctoral candidate, and also contains a strong training component by providing field experience for recent college graduates planning to attend graduate school.