Rising from the ashes
An Illinois furniture exhibition displays pieces made from ash trees killed by an invasive beetle.
Mon, Apr 27, 2009 at 04:02 PM
In every crisis, there are those who panic, and those who see the opportunities. Ash trees are dying by the millions in the Midwestern United States due to an invasive pest called the emerald ash borer, a shiny green beetle a half-inch long that preys on ash trees. The upshot is that ash wood—long relegated to utilitarian uses in tool handles, baseball bats, and firewood—is finally getting its due: Under the apt title “Rising from Ashes,” the Chicago Furniture Designers Association is organizing a series of exhibitions that, starting this August at the Morton Arboretum in Chicago, will feature furniture made of ash wood from trees killed by the emerald ash borer.
“This is one heck of an education tool,” says Bruce Horigan, a member of the association who owns Horigan Urban Forest Products, a hardwood sawmill in Skokie, IL. Horigan says the exhibition is a chance not just to clue people in about the ash borer and invasive species in general, but also to show them there “are better uses for [ash wood] than firewood or mulch.”
Ash is a hard yet springy wood (it was once used in snowshoe frames), ranging in color from creamy white to chocolate brown – perfect for durable, attractive furnishings. “This is visual lumber,” Horigan says. “It’s not the two-by-four behind the wall; it’s the paneling in front of the wall.” But most people don’t think of it that way – or didn’t, until ash suddenly became very available.
Though the emerald ash borer probably arrived in North America from Asia in the 1990s, it was first detected in Michigan in 2002; it has since spread across the Midwest and as far as West Virginia. It’s of particular concern in Illinois’ urban areas, where 20 percent of the trees are ash wood. The pest lays its eggs just under the bark of the ash tree, and when the larvae hatch, they feed on that sub-bark layer, eventually killing the tree. But it can be difficult to tell when a tree is infested: Dieback is gradual, and the tiny larvae lie dormant in winter and remain in the wood even after the tree dies.
The danger is that people don’t realize that the wood they’re transporting is infested, says Edith Makra, Community Trees Advocate at the Morton Arboretum and a member of the Illinois Emerald Ash Borer Wood Utilization Team, a consortium of around 80 foresters, arborists, and anyone interested in using ash wood and fighting the ash borer. Since then, the Illinois Department of Agriculture has embarked upon an awareness campaign and enforces strict quarantines on firewood to keep the ash borer contained – though Makra says it’s still hard to detect.
So a traveling furniture exhibition featuring previously infested ash wood sounded like an ecological disaster waiting to happen – that is, until Bruce Horigan explained the process under which he’s licensed to treat ash wood. The outermost layers of the tree—where the ash borer lives and eats—are ground up into tiny pieces too small to support the larvae. The rest of the wood – which technically is free from infestation because the ash borer’s larvae can’t penetrate the core of the tree – is heated in a kiln for 48 hours, just to be sure. Ash wood furniture, as long as it’s made from the heart of the tree, is perfectly safe. The only battle is getting people to want it.
“The idea of wood utilization has been around with urban foresters for years,” says Makra. “We’ve talked about how frustrating it is that we take down all these valuable trees in urban areas and nobody [uses] that timber.” Trees in urban areas are seen as less desirable, Makra explains, because they may have imperfections (like a nail from an old garage sale sign), or because a city may lack the infrastructure or extra budget to mill individual trees. But that could change, especially if exhibitions like “Rising from Ashes” have their intended effect.
Studies show that if urban timber (trees that succumb to disease or injury) were fully utilized, it could provide up to 30 percent of the United States’ timber needs. That would mean fewer trees logged from forests. How that timber is used matters, too: According to Horigan, burning firewood and spreading mulch release a lot of carbon directly into the atmosphere, whereas “higher” uses – like furniture – that leave the tree intact keep that carbon sequestered in the wood. With all the ash trees dying, there will be a surplus of ash wood no matter what, so using some of it for furniture might be preferable to having a bunch of extra mulch lying around.
John Kriegshauser and Dolly Spragins, co-chairs of the “Rising from Ashes” exhibition, say they expect up to 30,000 people to view the work of their 29 designers. After two weeks at the Morton Arboretum, the exhibition will visit furniture companies and conservation centers around Illinois through next spring. The featured pieces can be sold, but Spragins says they have to stay in the show – so designers who make a sale must craft duplicates for their customers.
The exhibition comes with the support of urban wood utilization groups like the Illinois Emerald Ash Borer Wood Utilization Team, which received a $100,000 Forest Service grant last year. Similar grants have gone to groups in Michigan that seek to combine urban wood utilization with education about the ash borer.
No one’s saying the emerald ash borer is a good thing. In addition to quarantines and monitoring, scientists are looking for solutions –some ideas that have been batted around include introducing parasitic wasps that eat ash borer larvae, cross-breeding American ash trees and their more resistant Chinese counterparts, or injecting trees with pesticides. But as long as the trees are falling, why not keep their beauty – and their carbon – around in the form of artistic design? It’s a simple case, in Horigan’s words, of making lemonade out of lemons.
Story by Alexa Schirtzinger. This article originally appeared in Plenty in June 2008.