A binational collaborative project is exploring environmental factors that affect the northward expansion of oak wilt, a fatal tree disease spread by sap beetles.
Researchers from Michigan Technological University and the Ontario Ministry of Natural Resources and Forestry in Canada are working to contain the spread of oak wilt. The fungal disease is currently found in 24 states and can decimate both forest and urban plantings, killing otherwise healthy trees. In addition to landscape blight, it impacts wildlife habitat and the timber industry.
The northern limit of the disease reaches the 46th parallel in Michigan, Wisconsin and Minnesota. The line hasn’t moved much since it was observed in the 1980s, but climate change is expected to impact the boundary in years to come as environmental conditions change. Project collaborators are particularly concerned about the establishment of oak wilt along the U.S.-Canada border and into Canada.
The idea for the project started when two colleagues got together for dinner. Tara Bal, assistant professor with the Michigan Tech College of Forest Resources and Environmental Science, discussed with her counterpart Sharon Reed why oak wilt, so close to the border, had not moved over the line in recent decades. Reed, the forest health research scientist for the Ontario Ministry of Natural Resources and Forestry, has studied oak wilt since 2017.
“We have oak trees and the beetle species (in Michigan’s Upper Peninsula), but the disease had not reached northern oaks in New York, Canada and elsewhere,” said Bal. “In June 2023, oak wilt was confirmed for the first time in southern Ontario, Canada.”
