Ash borer takes heavy toll on east coast trees
New York — Five prominent species of ash tree in the eastern U.S. have been driven to the brink of extinction from years of lethal attack by a beetle, a scientific group says.
Tens of millions of trees in the U.S. and Canada have already succumbed, and the toll may eventually reach more than 8 billion, the International Union for Conservation of Nature said Thursday.
Ash trees are a major part of eastern forests and urban streets, providing yellow and purplish leaves to the bounty of fall colors. Their timber is used for making furniture and sports equipment like baseball bats and hockey sticks.
The rampage of the emerald ash borer is traced to the late 1990s, when it arrived from Asia in wood used in shipping pallets that showed up in Michigan. Asian trees have evolved defenses against the insect, but the new North American home presented it with vulnerable trees and no natural predators.
Dan Herms, an entomologist at Ohio State University who studies the ash borer, called it “the most devastating insect ever to invade North American forests.”
Herms said he’s not sure the ash species will literally disappear.
But he said they could become “functionally extinct,” with populations too small to play a significant role in the environment for benefits like providing shelter and filtering water.