Doctoral Dissertation Improvement: Mycorrhizal legacy effects of a plant invasion may limit forest restoration

入侵植物对本地植物种群和群落有很大的直接影响。然而，入侵物种也可能通过遗产效应，以在物种本身消失后长期存在的方式改变环境。遗留效应可能是由于菌根互惠关系的破坏造成的，在这种情况下，植物依赖于某些土壤真菌来获得养分。我们还不清楚植物入侵对植物-真菌相互作用的影响程度，也没有人描述这些影响在入侵后作为遗产效应持续多久。苏格兰扫帚是一种侵略性灌木，引种后具有重要的生态和经济影响。该项目旨在了解苏格兰扫帚的入侵如何影响菌根，以及这可能对部分依赖菌根真菌的当地道格拉斯冷杉原生森林的恢复产生的后果。研究将结合大规模野外实验和观测研究、温室实验、土壤养分分析和最先进的分子方法来表征真菌群落，量化这一潜在生物入侵遗产的发展和持续的时间方面。除了它的学术价值，这项研究还将在资源管理方面产生更广泛的影响。主要目的是向管理层通报在重新造林的背景下引入的侵略性灌木。由于木材、农业和牧场生产以及野生动物的损失，苏格兰扫帚入侵对太平洋西北地区的区域经济造成了重大的经济影响。通过与私人和公共林农的密切合作，从这项研究中获得的信息将立即提供给管理人员。调查结果将在正式和非正式场合传播。来自不同背景的几名本科生将获得宝贵的实验室和实地研究技能，并就该项目的不同方面进行独立研究。

Invasive plants have large direct impacts on native plant populations and communities. However, an invasive species may also change the environment in ways that persist long after the species itself is gone, through a legacy effect. Legacy effects may be caused by the disruption of mycorrhizal mutualisms, in which plants rely on certain soil fungi for nutrient acquisition. We do not understand the degree to which plant invasions affect plant-fungal interactions, and no one has yet described how long these impacts persist after invasion as a legacy effect. Scotch broom is an aggressive, introduced shrub with important ecological and economic impacts. This project aims to understand how invasion by Scotch broom affects mycorrhizae and the consequences this may have for restoration of local, native forests of Douglas fir, which partly depend on mycorrhizal fungi. Research will quantify the temporal aspects of both the development and persistence of this potential legacy of biological invasion, using a combination of large-scale field experiments and observational studies, greenhouse experiments, soil nutrient analyses, and a state-of-the-art molecular approach to characterize fungal communities. Beyond its intellectual merits, this research will have broader impacts in resource management. A major aim is to inform the management of an aggressive, introduced shrub in the context of reforestation. Scotch broom invasion has significant economic impacts on the regional economy of the Pacific Northwest due to losses of timber, agriculture and range production, and wildlife. Through close collaborations with private and public foresters, the information gained from this research will be available immediately for management. Findings will be disseminated in both formal and informal settings. Several undergraduates from diverse backgrounds will gain valuable lab and field research skills and conduct independent research on different aspects of the project.