Sci­en­tists say ash trees on brink of ex­tinc­tion

Five species ‘crit­i­cally en­dan­gered’ by ash borer

Las Vegas Review-Journal (Sunday) - - NATION - By Mal­colm Rit­ter

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 al­ready have suc­cumbed, and the toll might 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 such as 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, Illi­nois. 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.

Mor­ton Ar­bore­tum The As­so­ci­ated Press

The In­ter­na­tional Union for the Con­ser­va­tion of Na­ture says five promi­nent species of ash tree, in­clud­ing th­ese blue ash, in the east­ern United States have been driven to the brink of ex­tinc­tion from years of lethal at­tack by the ash borer bee­tle.

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