RAPID: Decline and Resilience of White Ash Populations during an Emerald Ash Borer Invasion

这项研究代表着一个依赖时间的机会，可以更好地了解白蜡树是如何衰落的，并有可能抵抗入侵的翡翠白蜡树害虫甲虫，这种甲虫可能会使北美的白蜡树灭绝。这种翡翠白蜡虫最近在堪萨斯大学的一个野外监测站被发现，在那里，来自整个物种范围的44个不同的白蜡树种群都种植在一个田间地点。这项研究将集中于了解翡翠白蜡虫对白蜡虫种群的影响，白蜡虫种群因适应不同的起源环境而表现出不同的生理变化。这种变异可能是了解树木衰退和对翡翠白蜡虫的潜在抗性的关键。本研究将确定白蜡树种群对翡翠白蜡虫为害表现出快速下降、缓慢下降和无下降的反应，并确定白蜡树死亡和对翡翠白蜡虫潜在抗性的机制(S)。中学生将通过关于入侵物种及其对本地植被的影响的积极学习课程，向中学生介绍当地重要树种的科学研究。结果将向公众介绍入侵物种对本土树木保护的影响，以及本土植物提供的重要生态系统服务的破坏。这项研究将确定种内灰分下降的机制和对可能威胁到北美白蜡树属灭绝的翡翠白蜡虫的潜在抗性。最近在堪萨斯大学田间站的一个白蜡树(Fraxinus Americana)常见园地发现了翡翠白蜡虫，那里来自整个物种范围的44个种源已经种植了几十年。白蜡树对翡翠白蜡虫的抗性在种内的差异还知之甚少，这可能是在北美维持白蜡树功能性存在的关键。本研究将(1)鉴定潜在的白蜡树种源对翡翠白蜡虫的抗性，并勾画出影响这种抗性的关键化合物；(2)确定生理胁迫、翡翠白蜡虫种群密度和物理抗性能力在白蜡树对翡翠白蜡虫侵染反应中的重要性；(3)确定白蜡树二化螟致死的生理机制(S)。将测量韧皮部中假定的抗性化合物和机械损坏的韧皮部的伤口愈合率，以及随着新出现的翡翠白蜡虫侵袭的进行，垂死(和抗性)树的水力状况和碳饥饿的可能性。这位首席调查员将作为中学生的导师，并将主持关于入侵物种及其对生态系统的影响的积极学习课程。本科生将通过协助首席研究员和博士后在数据收集、手稿写作和外展活动中获得宝贵的实践研究经验。

This research represents a time dependent opportunity to better understand how white ash trees decline and potentially resist the invasive emerald ash borer beetle that threatens to eliminate ash trees from North America. The emerald ash borer was recently detected at a field station at the University of Kansas where 44 different populations of white ash from throughout the species range are all planted in one field site. The research will focus on understanding the effects of emerald ash borer on white ash populations that exhibit variations in physiology as a result of being adapted to different environments from which they originated. This variation may be key for understanding tree decline and potential resistance in response to emerald ash borer. The research will identify white ash populations that show rapid decline, slow decline, and no decline in response to emerald ash borer infestation, and identify mechanism(s) of ash mortality and potential resistance to emerald ash borers. Middle school students will be introduced to scientific research on important local tree species through active-learning sessions on invasive species and their effects on native vegetation. The results will inform public audiences on the effects of invasive species on conservation of native trees, and disruption of important ecosystem services provided by native plants. This research will determine mechanisms of intraspecific ash decline and potential resistance to the emerald ash borer that threatens to functionally extirpate the ash genus from North America. Emerald ash borer was recently detected at a white ash (Fraxinus americana) common garden site at the University of Kansas Field Station where 44 provenances from throughout the species range have been growing for several decades. Intraspecific variation in ash resistance to emerald ash borer is poorly understood and may be the key to maintaining the functional presence of ash in North America. This research will (1) identify potential white ash provenances with resistance to emerald ash borer and delineate critical compounds that contribute to this resistance; (2) determine the importance of physiological stress, emerald ash borer population density, and physical resistance capacity in ash response to emerald ash borer infestation; and (3) identify the physiological mechanism(s) of emerald ash borer-caused ash mortality. Measurements will be made of putative resistance compounds in phloem and the rate of wound-healing in mechanically-damaged phloem, as well as hydraulic status and potential for carbon starvation in dying (and resistant) trees as the emerging emerald ash borer infestation proceeds. The principle investigator will serve as a mentor for middle school students and will host active-learning sessions on invasive species and their effects on ecosystems. Undergraduate students will gain valuable hands-on research experience through assisting the principle investigator and postdoctoral fellow in data collection, writing of manuscripts, and outreach activities.