Weather Updates

Chicago could fell 10,000 trees over emerald ash borer: officials

Emerald Ash Borer  |  Phocourtesy Julie Moore

Emerald Ash Borer | Photo courtesy of Julie Moore

storyidforme: 65130995
tmspicid: 23436717
fileheaderid: 11452079

Updated: May 29, 2014 6:02AM

There is at least one way in which Chicago will likely come to resemble Detroit – the oft-evoked cautionary tale of a city.

Thanks to the tree-killing emerald ash borer beetle – which was first detected outside Detroit in 2002 – the number of ash trees in the Chicago area is expected to plummet – a phenomenon experts have already observed across much of Michigan.

“You don’t find ash trees around [Michigan] anymore. It’s reality. It’s what happens when you have a globalized world,” Andrea Dierich, a Morton Arboretum pest specialist, said of the beetle, which is indigenous to Asia and is believed to have reached the Midwest burrowed in shipping lumber.

“It is actually surprising Illinois has been as lucky as it has been, because of how much of a [trade] hub we are,” Dierich said.

Since last fall, city workers have cut down roughly 145 ash trees in one Northwest Side ward alone, officials said.

It was not the first time beetle-infested ash trees have had to come down in Chicago, according to city officials. Citywide, an estimated 10,000 ash trees on public property will eventually meet the business end of a chain saw, city figures suggest.

But some residents on the Northwest Side were concerned enough that they contacted their alderman.

“The emerald ash borer is really cutting through our urban forest,” said Owen Brugh, chief of staff to Ald. John Arena (45th), who represents the far Northwest Side ward where the trees were taken down. “Once you take that tree out . . . you’re left with a blank spot.”

The recently-felled ash trees raised aesthetic concerns amongst some in the ward, Brugh said. But the reduction of shade cover has also been shown to increase energy bills in the summer, due to the increased need for air conditioning, experts say. Not to mention the fact that trees reduce the level of pollution in the air while producing oxygen.

Without proactive — and expensive — steps, experts predict many other wards will have large gaps where ash trees, the most numerous species of tree in the city, once stood.

Mayor Rahm Emanuel, whose administration claims it can save the vast majority of the 85,000 ash trees on public property, set aside $1.6 million in 2014 for treating the pest, according to Molly Poppe, spokeswoman for the Department of Streets and Sanitation. By injecting ash trees every three years with the pesticide called Tree-age, city officials hope they can avoid a massive cut.

“As long as we are treating trees, we will have a solid ash population in the city,” said John Lough, a senior forester for the city. “We’ve had very good results with it.”

But given the cost, others question whether there is the long-term will to treat trees actually exists.

“If you have an unlimited pot of money it’s quite possible you can find products and solutions to stave off the damage,” said Tom Velat, an ecologist for the Forest Preserve District of DuPage County. “But nobody has an unlimited pot of money, so everyone has to make choices about what they want to do.”

The bigger question is the fate of an estimated 300,000 ash trees rooted on private property. Those make up the majority of ash trees planted in the city.

Treatment can be expensive for property owners, especially because the undertaking must be repeated every three years, experts say. Prices vary, but it could cost a homeowner upwards of $100 or more for each treatment, according to recent figures.

DuPage forest preserves, like Cook County forest preserves, have chosen to let nature work its course. Many of the infected ash trees on forest preserve property are in remote locations, officials for both counties said.

When infested trees are near high-traffic areas, the district opts to remove rather than treat, Velat said.

Realistically, municipal governments should focus efforts on diversifying the types of trees they plant, Velat said. The destruction wrought by the Ash Borer is awfully similar to the mass removal of elm trees after the outbreak of Dutch elm disease, which first erupted near Cleveland in the 1930s, experts say. Rather planting diversified tree types, in many cases diseased elms were replaced with the ash trees, now at the center of the current dilemma. On the Northwest Side, resident of Arena’s ward could start diversification efforts as early as May, when a ward election will be held to determine how much aldermanic money to spend on tree replacement, at a cost of $595 a tree.

“Having that nice canopy over a residential street is everybody’s ideal,” Brugh, the chief of staff, said.


Twitter: @BrianSlodysko

© 2014 Sun-Times Media, LLC. All rights reserved. This material may not be copied or distributed without permission. For more information about reprints and permissions, visit To order a reprint of this article, click here.