ShareThis Page

Scientists: Ash tree species pushed to brink of extinction

| Thursday, Sept. 14, 2017, 11:05 p.m.
In this Monday, March 9, 2015 file photo, a notice of removal is attached to an ash tree in Des Moines, Iowa. Daunted by the cost and difficulty of stopping the emerald ash borer, many cities are choosing to destroy their trees before the insect can.
In this Monday, March 9, 2015 file photo, a notice of removal is attached to an ash tree in Des Moines, Iowa. Daunted by the cost and difficulty of stopping the emerald ash borer, many cities are choosing to destroy their trees before the insect can.
This undated photo provided by the Morton Arboretum in September 2012 shows blue ash trees (Fraxinus quadrangulata). On Thursday, Sept. 14, 2017, the International Union for the Conservation of Nature said 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 the ash borer beetle.
This undated photo provided by the Morton Arboretum in September 2012 shows blue ash trees (Fraxinus quadrangulata). On Thursday, Sept. 14, 2017, the International Union for the Conservation of Nature said 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 the ash borer beetle.
In this Oct. 26, 2011 file photo, an emerald ash borer larvae is removed from an ash tree in Saugerties, N.Y. On Thursday, Sept. 14, 2017, the International Union for the Conservation of Nature said 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 the ash borer beetle.
In this Oct. 26, 2011 file photo, an emerald ash borer larvae is removed from an ash tree in Saugerties, N.Y. On Thursday, Sept. 14, 2017, the International Union for the Conservation of Nature said 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 the ash borer beetle.

NEW YORK — Five prominent species of ash tree in the eastern United States 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 United States and Canada have already succumbed, and the toll may 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.

“The populations are exploding,” said Murphy Westwood of the Morton Arboretum in Lisle, Ill. Infestations have been detected in 30 states.

“it's a very efficient killer,” Westwood said. “As the ash borer moves through a forest, it will completely kill all of the mature ash trees within three or four years.”

She led the scientific assessment that resulted in classifying the five species as critically endangered — meaning they are facing an extremely high risk of extinction in the wild. The change appears on the IUCN's Red List, considered by scientists the official index of what animals and plants are in danger of disappearing. The species are the green, black, white, pumpkin and blue ash.

A sixth species, the Carolina ash, was put in the less serious category of “endangered” because it might find some refuge from the infestation in the southern part of its range, which includes Florida, Texas and Cuba, Westwood said.

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.” It's already the most expensive because it has killed so many urban trees that had to be removed, disposed of and replaced, which has cost billions of dollars, he said.

Herms, who was not involved in the IUCN project, 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.

TribLIVE commenting policy

You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.

We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.

While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.

We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers

We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.

We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.

We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.

We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.