DISSERTATION RESEARCH: Assessing the relative effects of diversity, invader identity, nutrient input and disturbance on invasibility in low vs. high fertility grassland communities

外来生物的入侵在生态上是破坏性的，经济上代价高昂，了解促进生物入侵的因素是生态学研究的一个重要领域。现有本土物种的多样性、入侵物种的特征、放牧等干扰以及养分输入都被广泛认为是生态系统是否会受到入侵的潜在重要决定因素。然而，对于这些因素中的哪一个是最重要的，仍有很多争论和相互矛盾的证据。这场辩论在一定程度上源于一种倾向，即相互独立地研究这些因素。这项研究将所有这些因素放在一起考察，并询问它们的相对重要性如何随着土壤肥力的变化而变化，土壤肥力是自然界中一个主要的环境梯度，这将有助于促进我们对生物入侵的理解。这项研究将使用实验构建的植物群落，模拟土壤肥力低和高的原生中西部草原草原。原生植物多样性、干扰和养分输入将在这些群落中受到系统控制，这些群落将暴露在一系列功能多样的入侵物种中。这项研究将通过对促进入侵的关键因素的相对重要性的洞察，直接解决生物入侵知识的空白。从这项研究中获得的见解可能会提高预测和管理草原和其他社区入侵的能力。此外，这项研究将在印第安纳大学研究和教学保护区进行，这是一个为培养本科生研究活动和向当地社区交流科学提供绝佳机会的资源。

Invasions of non-native organisms are ecologically disruptive and economically costly, and understanding the factors that promote biological invasions is an important area of ecological research. The variety of existing native species, the traits of invasive species, disturbances such as grazing, and nutrient inputs are all widely recognized as potentially important determinants of whether an ecosystem will be invaded. Yet there is much debate, and conflicting evidence, over which of these factors are most important. The debate stems in part from the tendency to study these factors independently of one another. This study will assist in advancing our understanding of biological invasions by examining all of these factors together, and asking how their relative importance changes with soil fertility, which is a major environmental gradient in nature. The study will be conducted using experimentally constructed plant communities modeled on native mid-western prairie grasslands of low and high soil fertility. Native plant diversity, disturbance and nutrient inputs will be systematically manipulated in these communities, and the communities will be exposed to an array of functionally diverse invasive species. This study will directly address a gap in knowledge of biological invasions by providing insights into the relative importance of key factors in promoting invasions. The insights gained from this study may enhance both the ability to predict and to manage invasions of grasslands and other communities. Furthermore, this study will be conducted at the Indiana University Research and Teaching Preserve, a resource that offers excellent opportunities for fostering both undergraduate research activity and communicating science to the local community.