DISSERTATION RESEARCH: The dynamic role of natural enemies during plant invasions

当植物、动物和其他物种被引入历史上从未出现过的地区时，生物入侵就产生了。入侵物种每年给世界各地的本地生态系统和人类利益造成超过1370亿美元的损失。然而，尽管它们很重要，而且经过了50多年的深入研究，但对于它们成功的原因却没有达成共识。该项目的目标是验证解释入侵物种成功的一个关键假设：生物入侵的发生是因为入侵植物物种在其原生范围以外的地区没有受到竞争对手、捕食者和食草动物的强烈影响。此外，虽然新引进的物种可能不会受到新敌人的伤害，但这种现象可能是暂时的——随着时间的推移，入侵物种可能会获得更多的敌人。这些想法将通过在野外环境中种植本地的、非侵入性的和侵入性的植物物种来检验，在野外环境中，敌人（食草动物和疾病）的存在已经被实验控制。一个关键的预测是，与本地和非入侵植物相比，移除敌人不会对入侵物种有利，因为它们已经受到了敌人的轻微伤害。此外，很久以前引入的入侵物种可能会开始像本地物种一样，并从敌人的移除中受益。鉴于生物入侵造成的经济成本和环境危害，了解导致它们与本地和非入侵引入物种不同的原因是很重要的。这项研究将有助于确定哪些因素有助于入侵成功；这样做可以帮助预测和防止未来的入侵。这项工作还将有助于预测入侵的长期后果（例如，它们是否会继续成为问题，或者敌人的积累是否最终会限制它们的影响）。结果将被广泛分享，包括学术观众、普通公众和K-12学生。合作项目将与密歇根州西南部农村学校的小学、初中和高中教师合作，为学生和教师的发展制定课程计划和研讨会，涵盖入侵生物学、社区生态学和进化等主题。该联合项目将继续指导追求科学事业的本科生和高中生。

Biological invasions result when plants, animals, and other species are introduced into regions where they did not historically occur. Invasive species cause over $137 billion in damages to native ecosystems and human interests around the world every year. Yet, despite their importance and over 50 years of intensive study, there is no consensus about what underlies their success. The goal of this project is to test one of the key hypotheses explaining the success of invasive species: biological invasions occur because invasive plant species are not strongly impacted by competitors, predators, and herbivores in areas outside their native range. Additionally, while newly introduced species may receive little damage from novel enemies, this phenomenon may be temporary -- invasive species may acquire more enemies over time. These ideas will be tested by planting native, non-invasive introduced, and invasive introduced plant species into field environments where the presence of enemies (herbivores and disease) has been experimentally manipulated. A key prediction is that removal of enemies will not benefit invasive species, compared to native and non-invasive introduced plants, as they are already experiencing little damage from enemies. Further, invasive species introduced longer ago may start to resemble native species and benefit from the removal of enemies.Given the economic costs and environmental harm caused by biological invasions, it is important to understand what causes them to differ from native and non-invasive introduced species. This research will help determine what factors contribute to invasion success; doing so can help predict and prevent future invasions. This work also will help to predict the long-term consequences of invasions (e.g., whether they will continue to be problematic or whether the accumulation of enemies will eventually limit their impacts). Results will be shared broadly, including academic audiences, the general public, and K-12 students. Working with elementary, middle, and high school teachers in rural schools across southwest Michigan, the co-PI will develop lesson plans and workshops for student and teacher development, covering topics such as invasion biology, community ecology, and evolution. The co-PI will continue to mentor undergraduate and high school students pursuing scientific careers.