Dissertation Research: Linking an Invasive Ecosystem Engineer with Community and Ecosystem-Level Impacts: North American Beaver Effects on Stream Food Webs of Southern Chile

外来入侵物种对生态系统的影响是生态学研究的一个重要领域。了解物种和生态系统对外来环境的依赖反应，对于理解和预测当前对脆弱系统的影响和未来的变化是必要的。北美海狸引入智利南部是一个特别引人注目的案例，因为海狸有能力设计整个生态系统。这种引入正在产生破坏性的影响，导致森林和溪流发生戏剧性变化。溪流食物网依赖于森林中的有机物和遮荫。这项研究利用新技术研究了河狸对溪流无脊椎动物群落结构、次生生产力、营养能流和食物网动态的影响。根据北美的研究，由于南美洲海狸和森林的植被和进化史的差异，预计海狸的累积影响，即塑造和构建非土著社区和生态系统功能，可能无法预测。这篇论文的更广泛的影响将包括与智利当地合作伙伴的合作研究、教育和保护倡议，这些倡议将使研究的重要部分得以完成，并为当地的努力提供支持和投入。

The impact of invasive, introduced species on ecosystems is a critical area of research for ecology. Understanding the context-dependent responses of species and ecosystems to exotics is necessary to comprehend and predict current impacts and future alterations to vulnerable systems. The North American beaver introduction into southern Chile is a particularly compelling case because of the beaver's ability to engineer entire ecosystems. This introduction is having destructive impacts, causing dramatic changes in forests and streams. Stream food webs depend on forests for organic matter and shading. This study addresses the beaver's influences on stream invertebrate community structure, secondary production, trophic energy flow and food web dynamics in response to changes in streamside forest cover using novel techniques. It is expected that the beaver's cumulative impacts, shaping and structuring non-native communities and ecosystem function, may not be predictable based on North American studies, due to differences in vegetation and evolutionary history of beaver and forests in South America. The broader impacts of this dissertation will include cooperative research, education and conservation initiatives with local Chilean partners that will allow important parts of the research to be accomplished and also provide support and input to the local efforts.