Invasive Species Research

Ongoing research

Kudzu habitat suitability in the Great Lakes region. Kudzu is an invasive plant species common throughout the southeastern United States that was originally introduced at the 1876 Centennial Exposition in Philadelphia as part of the Japanese pavilion. It was later distributed and promoted as high-quality animal fodder and to control soil erosion. Recently, kudzu has been found in several new counties in Indiana and Michigan, which raises the concern of further spread and invasion into more of the Great Lakes region. This project is focused on understanding the susceptibility of invasion in the Great Lakes region and will use several environmental and land use characteristics to identify potential invasion likelihood.

Long-term forest responses to emerald ash borer invasion. Since its introduction in the late-1990s, emerald ash borer has colonized forests throughout much of the eastern half of North America. There are several species of ash that are highly susceptible to emerald ash borer attack, resulting in widespread mortality due to this pest. As part of a long-term study, the Plant Ecology Lab is regularly surveying forests throughout the Lower Peninsula of Michigan, northeastern Indiana, and northwestern Ohio to understand forest changes because of losing ash from the canopy. Early results suggest that the loss of ash cause compositional changes that were greater than just the subtraction of ash – meaning the influence of ash was greater than just its presence. Additionally, even though nearly 85% of ash was lost from these forests, green ash was the most abundant midstory and understory species. While this latter result is promising for future forests contain ash, the question still remains: how long will ash stay part of these forests?

Ash dominating the midstory at a site in Chain O’Lakes State Park, India

Ash seedlings in the understory at a site in Pearson Metropark, Ohio.

Previous research

Callery Pear Management in Prairies.

The controlled burn at Arrowhead Prairie in April 2014.

Callery pear (Pyrus calleryana) is an invasive tree introduced to the United States for ornamental purposes. It easily invades disturbed prairies, causing a disruption to natural interactions. The objective of this research was to assess fire as a suitable tool to manage Callery pear in a restored prairie. Adam Warrix (PFW graduate student) and Jordan Marshall (PFW faculty member) conducted the study at Arrowhead Prairie, which is managed by Little River Wetlands Project. Results from this project provided a clear response by Callery pear to fire – established seedlings and trees all responded positively to fire with 3-4 new stems per plant. Only seeds failed to germinate after fire. While fire alone did not kill Callery pear, burning the surrounding vegetation made the pear stems much more obvious. When the current removal technique is cutting and spraying stumps with herbicide, more obvious pear stems will be more easily located.