Evaluating the mechanisms that result in a relationship between phylogenetic distance and population dynamics in biological invasions.

Washington University, Saint Louis MO

Investigators

Abstract

Although humans have transported thousands of species of plants and animals across the globe, the ability of those species to establish, spread, and cause significant economic and ecological costs in the areas to which they have been introduced varies greatly. Many hypotheses have been proposed to understand why some introduced species harm the ecosystems to which they are introduced while others are apparently innocuous. Most famously, Darwin hypothesized that introduced species that are less closely related to the native species in a habitat are more likely to cause harm, that is, to become invasive. This research will focus on three prominent mechanisms that might explain how evolutionary novelty in plants could lead to invasion following introduction: competition, natural enemies, and pollination. Novelty could allow introduced plants to escape both competition from other plants and attack by predators and pathogens. However, novelty could deprive introduced plants of pollinators. Researchers will test the effects of competition, herbivory, and access to pollinators on the performance and predicted population growth of each of 20 introduced plant species that vary in invasiveness and novelty at a field site near Saint Louis, Missouri. Results will help show the costs and benefits of evolutionary novelty in introduced species. In addition to providing a more thorough understanding of the important environmental problem of invasive species, this study will provide useful information for cost-effective ways to limit the introductions of potentially invasive species and to manage species that have already been introduced. The research will also train graduate and undergraduate students and reach out to the public through an informal science education program with high school interns and through presentations to public audiences.