URI researcher: Newly arrived beech leaf disease could kill local beech trees

The dark bands on these beech leaves are an indication of beech leaf disease. (Photo courtesy of Heather Faubert)
The dark bands on these beech leaves are an indication of beech leaf disease. (Photo courtesy of Heather Faubert)

KINGSTON, R.I. – September 14, 2020 – A University of Rhode Island scientist said that a disease that can kill beech trees was discovered in southwest Rhode Island in June, and both American and European beech trees throughout the region are at risk.

According to Heather Faubert, who coordinates the URI Plant Protection Clinic, beech leaf disease was first identified in Ohio in 2012, and it spread to Pennsylvania, New York and Connecticut before arriving in Rhode Island. The disease damages a tree’s leaves, causing them to fall off. The energy required to regrow leaves stresses the trees, and if it happens several years in a row, the trees could die.

“It’s really sad that it’s arrived here because beeches make such beautiful forest trees,” Faubert said. “Beech forests are stunning, their bark is gorgeous, and in fall their leaves turn a beautiful coppery color.”

She said the disease is caused by a nematode, a microscopic worm that feeds inside the leaves.

“It’s very easy to see if a tree is infected,” Faubert said. “If you hold a leaf up to the sun and you can see dark bands running parallel to the veins of the leaves, that’s the sign of an infected tree.”

No treatment for the disease is available, as nematodes are difficult to control in the forest environment, but research is underway to identify treatments for individual landscape trees.

“That’s the worst part; we don’t know what to do about it yet,” said Faubert, who observed diseased trees in an extensive area of beeches in Ashaway but did not find it in beech forests in Portsmouth or Middletown. “We also don’t know how it’s being transmitted from tree to tree, so if people walk around in the area of diseased trees, they should probably wash the bottom of their shoes before going into another forest.”

She also advises that residents avoid digging up beech tree saplings from one forest and transplanting them elsewhere so as not to move potentially diseased trees to uninfected areas.

Those who believe they have beech trees infected with beech leaf disease should take a photo and report it on the Rhode Island Department of Environmental Management’s invasive species pest report form at http://www.dem.ri.gov/programs/agriculture/pests.php.