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

这项研究提供了一个随时间变化的机会，可以更好地了解白白蜡树是如何衰退的，并有可能抵御威胁北美白蜡树灭绝的入侵的祖母绿灰螟甲虫。最近在堪萨斯大学的一个野外站点发现了祖母绿灰螟，在那里，来自整个物种范围的44个不同种群的白灰都种植在一个野外站点。研究的重点是了解绿灰螟对白灰种群的影响，白灰种群由于适应了不同的环境而表现出生理上的变化。这种变异可能是了解树木衰退和对绿灰螟虫潜在抗性的关键。该研究将确定白蜡树种群对绿灰螟虫的侵害表现出快速下降、缓慢下降和不下降的反应，并确定白蜡树死亡的机制和对绿灰螟虫的潜在抗性。中学生将透过主动学习课程，了解外来入侵物种及其对本地植被的影响，了解本地重要树种的科学研究。研究结果将使公众了解入侵物种对本地树木保护的影响，以及对本地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祖母绿灰分蛀虫的潜在抗性，这种蛀虫威胁着北美灰分属的功能灭绝。最近在堪萨斯大学野外站的一个白蜡（美洲蜡属）普通花园遗址发现了祖母绿灰螟虫，在那里，来自整个物种范围的44个种源已经生长了几十年。白蜡树对祖母绿灰螟虫的抗性种内变异尚不清楚，这可能是维持北美白蜡树功能存在的关键。本研究将(1)确定对绿灰螟虫具有抗性的潜在白灰种源，并描述有助于这种抗性的关键化合物；(2)确定生理胁迫、绿灰螟虫种群密度和物理抵抗能力在白蜡树应对绿灰螟虫侵害中的重要性；(3)确定了翠绿灰螟引起的灰分死亡的生理机制。将测量韧皮部中假定的抗性化合物和机械损伤韧皮部的伤口愈合速度，以及随着新出现的翠绿灰螟虫侵扰的进行，垂死（和抗性）树木的水力状态和碳饥饿的可能性。首席研究员将担任中学生的导师，并将主持有关入侵物种及其对生态系统影响的主动学习会议。本科生将通过协助主要研究者和博士后收集数据、撰写论文和拓展活动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.