European ash is a significant tree commercially, ecologically, and culturally. It is currently
threatened by two invasive species, the fungus that causes ash dieback and

Oak decline is a slow-acting disease complex that involves the interaction of biotic and abiotic factors such as climate, site quality and advancing tree age.

Fall is a beautiful and often very busy season for Gardens and Arboretums, with many guests visiting to enjoy cooler weather, Fall colors, and other seasonal events.

Interception of potential invasive species at ports-of-entry is essential for effective biosecurity
and biosurveillance programs. However, taxonomic assessment of the immature stages

Ice or snow loads can cause branch breakage or failure of entire trees and shrubs. Branches or entire trees that fall in storms can impact homes, vehicles, power lines and block roads.

ManagementEmerald ash borer (Agrilus planipennis) was first discovered in southeastern Michigan in 2002.

• Many exotic plant pests and pathogens are unknown prior to their establishment, making prevention and management difficult.

The invasive hemlock woolly adelgid (HWA) has decimated hemlock stands across much of the eastern United States, and presents a significant threat to all eastern hemlock in Canada across Ontario, Quebec, New Brunswick, Nova Scotia, and Prince Edward Isl

Insect and disease infestations pose major threats to several North American forest tree species.

Urban trees serve a critical conservation function by supporting arthropod and vertebrate communities but are often subject to arthropod pest infestations.