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Upstaging the ash borer

Eagan has turned downed trees into flooring and paneling at the new fire station, making lemonade, so to speak, from wood that would have been burned or chipped into mulch.

January 26, 2011 at 2:13AM

Reid Lemaire of Crossroads Construction worked on an area of white ash paneling at the new Eagan Fire Safety Center. The ash was salvaged from approximately 100 trees that were cut as defense against the emerald ash borer. (Star Tribune/The Minnesota Star Tribune)

For the finishing touches on the new Eagan Fire Safety Center, city officials chose a silver lining.

Paneling and flooring in the $8 million combination fire station, administrative center and museum are coming from ash trees cut down from city boulevards last year as part of an effort to remove trees before the emerald ash borer gets them. That the doomed trees are enduring as richly variegated and durable wood in a showy public space is a bonus for Fire Chief Mike Scott.

"We're really excited," Scott said. "We weren't sure what ash would look like, but it's prettier than I'd thought."

The new fire center will replace two fire stations that are being closed. But it also represents one of the first large solutions to a growing North American puzzle: What to do with all the ash that could be felled either by the emerald ash borer or by foresters trying to spread out the insect's impact?

Since its arrival near Detroit in the 1990s, emerald ash borer has been detected in 13 states and two Canadian provinces and is considered a threat to about 900 million trees in Minnesota, which has the second-greatest concentration of any state.

Effective chemical insecticides are available, but landowners, including public agencies, aren't likely to be able to afford to treat all their ash, many of which were planted a generation ago in response to Dutch elm disease.

An underestimated hardwood

Ash borers will kill any untreated tree in a few years by disrupting its nutrient supply just under the bark. But wood from the rest of the tree can be put to numerous uses. Ash is easy to see swatting baseballs around Major League ballparks (though some bats are maple). An attractive hardwood, it's also used to make furniture, baskets and tool handles.

But ash currently makes up only about 5 percent of the commercial hardwood lumber market, making it a very minor player compared to red and white oak (45 percent), said Dan Cassen, professor of forest products at Purdue University. Most ash cut down in cities in recent years, in fact, has been burned to produce energy or chipped to make garden mulch.

"I don't like to call it waste. I like to call it a wood resource," said Jessica Simons, natural resource specialist with the Southeast Michigan Resource Conservation and Development Council. That group is trying to revive and create markets for the ash being removed from cities. But there are obstacles.

One, Simons and Cassen said, is the popularity of oak, even though ash is often mistaken for it. Another is a resistance to city wood from sawmillers, who fear it often contains nails, staples, hooks and other hardware. A third is the cost of shipping logs from a city to usually distant sawmills.

An idea takes off

The Eagan project actually owes something to oak. Plans for the new fire center called for removal of an old bur oak tree -- not a good thing in a city whose logo is an oak, Scott noted.

That got Scott thinking about reusing lumber from the oak tree to reline the bed of the city's first firetruck, which will be on display in the new fire center. He called city forester Gregg Hove, who had just removed 100 ash from city streets, and the re-use idea expanded. With an $89,000 grant from the Minnesota Department of Agriculture, they had the oak and ash sawn into tongue-and-groove paneling and flooring at a sawmill in Mankato.

"It's the perfect example of how [ash] can be used for higher-end products," said Steve Bratkovich, program manager for recycling and reuse for Dovetail Partners, a Minneapolis environmental consulting firm.

Bill McAuliffe • 612-673-7646

Adult emerald ash borer (Associated Press/The Minnesota Star Tribune)