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

Michigan State University, East Lansing MI

Investigators

Abstract

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.