By: Grant Seagull
A tree disease first spotted 9 years ago in Ohio is now a leading threat to one of eastern North America’s most important trees. The poorly understood malady, called beech leaf disease, is spreading rapidly and killing both mature American beeches and saplings, new research shows.
“This study documents how rapidly [the disease] has spread since its first observation in 2012,” says Robert Marra, a forest pathologist at the Connecticut Agricultural Experiment Station who was not involved with the work.
American beeches (Fagus grandifolia) are found across the eastern United States and Canada. The trees, which can grow nearly 40 meters tall and live up to 400 years, are a major player in many forests. Beeches constitute more than 25% of forests in Vermont, for example.
Historically, a blight called beech bark disease has been the primary threat to the species. But now, beech leaf disease appears to pose a bigger danger. First spotted in northeastern Ohio, it causes parts of leaves to turn leathery and branches to wither. The blight can kill a mature tree within 6 to 10 years. It has now been documented in eight U.S. states and in Canada.
In Rhode Island, observers first spotted beech leaf disease in 2020, confined to a small area, says Heather Faubert of the University of Rhode Island’s Plant Protection Clinic who was not involved with the study. But, “This year, it’s everywhere.”
