Maine is known for its abundant forests, and Acadia National Park is no different. Many of the park’s lowland trails wind through leafy wetland forests of red maple and ash, or follow cold burbling streams under canopies of hemlock and pine. But several of Maine’s key forest tree species are facing threats which could fundamentally change the structure and ecology of forest ecosystems.
As the last century has brought warming temperatures and rapidly increasing global trade, many insect species have found themselves inadvertently brought to new continents in nursery stock or wooden packing materials. Some have flourished as they encountered tree species with no natural defenses, and few predators who recognize them as potential prey.
To protect the park’s forested ecosystems and the species that depend upon them, Acadia National Park managers are proactively planning to manage forest insect threats, with the help of Schoodic Institute scientists. By identifying priority areas to protect, identifying potential strategies to control insect populations, and creative comprehensive monitoring plans to detect when and where populations become established, park managers can be well-prepared to act when new pests arrive.
Two priority insects in Acadia are the hemlock woolly adelgid (Adelges tsugae) and emerald ash borer (Agrilus planipennis), which feed on eastern hemlock (Tsuga canadensis) and several species of ash (Fraxinus spp.) respectively, often with fatal consequences. These tree species are ecologically and culturally important parts of the eastern forest. Among many other relationships, hemlocks provide crucial habitat for a number of specialist wildlife species, and brown ash is used by Wabanaki artisans in their practice of basketry. Protecting these trees and the relationships they sustain is a priority for park managers.
In partnership with neighboring land managers and communities, Schoodic Institute scientists and park managers are actively developing management plans for these two important tree species and the introduced insects that threaten their survival. As climate changes and pest species move across the landscape, we will continue to work together to address new forest insects in the future.