EAGER: Uncovering the role of altered cryptic interactions in driving the demographic success of a range-expanding species

生态群落是由密切相互作用的物种组成的。由于组成这些群落的物种对环境变化的反应不太可能是同步的，因此进入新地区的物种可能会把相互作用的物种抛在后面，或者可能会在前进的过程中沿着建立新的联系。了解这些不断变化的关系的结果是非常重要的，因为物种正在以前所未有的速度改变它们的分布，因为这些变化可能会影响生态系统和人类福祉。这项研究使用正在扩大其范围的橡树黄蜂来研究这些变化如何影响它们与竞争对手，捕食者和宿主植物的相互作用。了解这些不断变化的关系可以解释最近这些黄蜂的爆发。 该项目的信息将有助于了解范围扩展的结果以及如何有效地管理爆发物种。该项目还将为学生和公众提供关于昆虫对生态系统和社会的重要性的教育和宣传机会。为了研究短距离范围扩张的社区动态，该项目利用了一种独特的易处理的橡树瘿形成黄蜂的研究系统，该黄蜂最近在西部橡树稀树草原生态系统中向北扩展了其范围。该物种在其扩展范围内的橡树上达到了比其原生范围更高的密度。这些种群爆发可能是由于其与生态群落的相互作用在其扩大的范围内发生了变化，包括其宿主植物的不同种群以及不同的敌人（寄生蜂）和竞争对手（共同发生的橡树瘿形成黄蜂）。该项目测试了几种假设，改变相互作用如何促进爆发，包括宿主植物种群的易感性差异的重要性，以及与竞争对手和共享寄生性敌人的相互作用。测试改变的相互作用如何促进对范围扩展的响应的爆发的最有效方法是比较在原生范围和扩展范围中的相互作用的强度。在这种地理尺度上进行实验是具有挑战性和风险的，特别是在一个新的研究系统中，但最近的扩张提供了一个早期的机会，以了解范围扩张的直接后果。一个普通的花园实验将测试两个范围内宿主植物抗性的差异。此外，eDNA（环境DNA）技术将被用来比较适应性错配寄生虫，瘿前在这两个地区的相互作用。这项研究将导致对短距离范围扩展的社区动态的新见解。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Ecological communities are composed of closely interacting species. As species that make up these communities are unlikely to be synchronous in their responses to changing environments, species moving into new areas may leave interacting species behind or may pick up new associations along the way. Understanding the outcomes of these changing relationships is important because species are shifting their distributions at unprecedented rates, and because these changes may impact ecosystems and human well-being. This study uses oak wasps that are expanding their ranges to examine how these changes influence their interactions with competitors, predators and their host plants. Understanding these changing relationships may explain recent outbreaks of these wasps. Information from this project will contribute to understanding the outcomes of range expansions and how to effectively manage outbreaking species. This project will also provide educational and outreach opportunities to students and the public regarding the importance of insects to ecosystems and society. To examine the community dynamics of short-distance range expansions, this project leverages a uniquely tractable study system of an oak gall-forming wasp that recently expanded its range northward in western oak savanna ecosystems. This species reaches higher densities on oaks in its expanded range compared to its native range. These population outbreaks are likely due to changes in its interactions with the ecological community in its expanded range, including a different population of its host plants and different suites of enemies (parasitoid wasps) and competitors (co-occurring oak gall-forming wasps). This project tests several hypotheses of how altered interactions facilitate outbreaks, including the importance of differences in the susceptibility of host plant populations, and interactions with competitors and shared parasitoid enemies. The most powerful way to test how altered interactions facilitate outbreaks in response to range expansions is to compare the strength of interactions in the native and expanded range. Conducting experiments at this biogeographical scale is challenging and risky, especially in a new study system, but this recent expansion provides an early opportunity to understanding the immediate consequences of range expansions. A common garden experiment will test for differences in host plant resistance across both ranges. In addition, eDNA (environmental DNA) techniques will be used to compare adaptive mismatches in parasitoid-gall former interactions in both regions. This research will result in novel insights into the community dynamics of short-distance range expansions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.