Oak Lawn, neighboring towns combat tree-killing pest
BY MIKE NOLAN firstname.lastname@example.org October 12, 2012 5:12PM
Heather Green, forester for Oak Lawn, stands on the stump of a dead ash tree on Keating Avenue south of 110th Street in Oak Lawn. More than 200 trees in that neighborhood have been infested by the emerald ash borer and are targeted for removal. | Matt Ma
The emerald ash borer has been blamed for destroying tens of millions of ash trees around the Midwest, and Southland communities are battling the bug.
Adult beetles lay eggs on the bark, and the larvae, once they emerge, burrow their way through the bark and nibble away at the tree’s vascular tissue. That’s the part of the tree that carries water and other nutrients to all parts of the tree, and without it the tree dies of thirst. Because the eggs are laid fairly high up in the tree, the lower half might still look fairly healthy, and one indication of beetle infestation is the development of new sprouts around the lower section of the tree. Once a tree is infested by the emerald ash borer, it can take up to four years before the damage is evident.
Oak Lawn and Boy Scout Troop 618 will host a public information meeting on the emerald ash borer at 1 p.m. Sunday at the Community High School District 218 administration building, 10701 Kilpatrick Ave. in Oak Lawn. Troop 618 and Eagle Scout candidate JP Murphy will give a presentation on the borer, what you should do if you have an ash tree, and the importance of choosing the right replacement tree.
Updated: November 19, 2012 6:01AM
On the east side of Keating Avenue south of 110th Street in Oak Lawn, the stump of a felled ash tree serves as a teaching tool for Heather Green.
The bark removed, the stump bears squiggly lines where the larvae of the emerald ash borer nibbled away at the tissue that carried water and nutrients throughout the tree, causing it to essentially die of thirst.
It’s a death being repeated up and down Keating as well as Kilpatrick Avenue to the east. For the residents of the apartments and townhomes lining the streets who want to know why their trees — more than 200 in all — soon will be cut down and shredded, Green, Oak Lawn’s forester, can point to that stump.
Public lands in Oak Lawn — parkways and the like — contain more than 1,600 ash trees. How many other ash trees susceptible to infestation that are on private property is anybody’s guess.
But Green is convinced that virtually all the trees ultimately will fall victim to the emerald ash borer, an Asian beetle.
“If you have an ash tree, there is a 99.9 percent chance you have (emerald ash borer),” she said.
But it can take four years before signs of the destruction are evident, so even trees that, for now, appear to be healthy already could be in their death throes. A section of Oak Lawn east of Cicero Avenue, between 107th and 111th streets, is the village’s worst area as far as infestation, and although several trees have been cut down, many more bear a red “X” painted on their bark, meaning they’re next in line.
Walking through the neighborhood, Green points to thinning leaves high up in the trees, evidence of the beetle. The borers lay eggs fairly high up in the tree, and that’s where their larvae go to work. The lower half of the tree still appears healthy, but that’s because it’s still getting water and nutrients, which aren’t reaching other parts of the tree.
Oak Lawn fortunate
The 1,600 ash trees represent a bit more than 8 percent of all trees on public land in the village, which puts Oak Lawn in a better position than some other Southland communities. Green said that in some towns, ash trees account for 20 percent or more of their public tree inventory.
According to the U.S. Department of Agriculture, the ash is the preferred tree for new residential and commercial developments, so suburbs that have had substantial growth in recent years could potentially lose more trees than older, more fully built-out communities.
First spotted in 2002 in southeastern Michigan — and confirmed in Illinois in June 2006 — the pest has since made its presence known in 15 states and has been blamed for already killing tens of millions of ash trees.
With the borer having no known natural predator in this country, government agencies are testing stingless wasps native to China, where the beetle originated.
The U.S. Forest Service estimates that the ash borer, if not contained and eradicated, could cost state and local governments $7 billion over the next 25 years to remove and replace dead and dying ash trees, and that green, white and black ash all are at risk for infestation.
Along with Oak Lawn, communities throughout the Southland are dealing with the effects of the bug. Tinley Park officials recently approved buying nearly 430 trees to replace infested ash trees that have been cut down, and Orland Park is hiring a firm to remove dead and dying trees.
Drought fallout still to come
Green, who’s spent the last 10 years as the village’s forester, said that aside from the ash borer, trees of all varieties still are feeling the effect of this year’s severe drought.
“Although we have been getting rains, it’s not enough to reverse the damage for many trees, particularly if they were suffering from other issues to begin with,” she said.
Green said it could take from one to five years to see the full impact of the drought, which could further decimate trees in Oak Lawn and other communities. She said that Oak Lawn, in a typical year, loses 300 to 350 trees in public areas due to natural attrition or things such as storm damage, but that number could be higher factoring in the drought.
Still, Green said she has more pressing concerns.
“I have 1,600 dying trees that I know about,” she said.
The village is using public works crews to remove bug-infested trees, but with all they have to do maintaining streets and other infrastructure, the process isn’t moving as quickly as Green hoped. Originally, she thought the trees along Keating and Kilpatrick might have been cleared by the middle of July.
“It’s getting overwhelming,” she said of the task. “It’s a lot to do, and resources are limited.”