Introduced, invasive species are known to have negative effects on our native ecosystems, but the mechanisms that drive invasions are not well understood. One introduced plant now abundant in Eastern deciduous forests, garlic mustard (Alliaria petiolata), is thought to release toxic chemicals that harm native plant species. Furthermore, garlic mustard has a longer growing season than most native forest plants, allowing it to take advantage of light during the fall, winter, and spring when natives are dormant. These mechanisms may reinforce one another if the extra light available to garlic mustard during its extended growing season is used to increase production of chemical toxins. This project will test this hypothesis by measuring the growth, chemical production, and impact of garlic mustard on native species in the presence and absence of extended light availability. Results will help to fill an important gap in our understanding of invasion biology by showing how interactions between mechanisms may increase the invasiveness of introduced species.
Invasive plant species threaten native biodiversity throughout the United States, and impose significant economic costs (approximately $137 billion/year). For example, forest invaders such as garlic mustard may inhibit forest regeneration and cause long-term reductions in timber production, recreation, and other services that forests provide. Understanding the mechanisms that drive invasion will facilitate more effective mitigation and prevention, helping to reduce the environmental, economic, and social costs associated with plant invasions. This project will also promote the scientific and ecological literacy of undergraduate and high school students participating in the research, and of members of the public reached through a public lecture and a nature center exhibit on the threats of invasive species and the steps that can be taken to protect the biodiversity and ecosystem services provided by our native forests.
