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不太可能对不断变化的环境做出同步反应，进入新区域的物种可能会把相互作用的物种抛在后面，或者在此过程中建立新的联系。了解这些关系变化的结果很重要，因为物种正在以前所未有的速度改变它们的分布，而且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活动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、捕食者和寄主植物的互动。了解这些不断变化的关系可能会解释最近这些黄蜂的爆发。来自该项目的信息将有助于理解范围扩大的结果，以及如何有效地管理暴发物种。该项目还将向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推广机会。为了研究短距离范围扩张的群落动态，该项目利用了一种独特的易驯化的研究系统，研究了一种最近在西部橡树稀树草原生态系统中向北扩展其活动范围的橡树虫害形成黄蜂。本种在其扩展的范围内与其原生范围相比在橡树上达到更高的密度。这些种群暴发可能是由于在其扩大的范围内与生态群落的相互作用发生了变化，包括寄主植物的不同种群以及不同的天敌(寄生蜂)和竞争对手(共生的橡树瘤形成蜂)。这个项目测试了几个关于相互作用改变如何促进疫情爆发的假说，包括寄主植物种群敏感性差异的重要性，以及与竞争对手和共同的寄生蜂敌人的相互作用。要测试变化的相互作用如何促进疫情对范围扩大的响应，最有效的方法是比较自然范围和扩大范围内的相互作用的强度。在这种生物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，但最近的这种扩展为理解范围扩大的直接后果提供了一个早期机会。一个常见的花园实验将测试这两个范围内寄主植物抗性的差异。此外，EDNA(环境DNA)技术将被用来比较两个地区寄生蜂与原寄生蜂相互作用中的适应性错配。这项研究将对短距离扩展的社区动态产生新的见解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.