As ash borer infestation spreads, communities consider what to do with trees

As emerald ash borers munch their way ever further into the Northland, one fact seems certain: We're going to lose a lot of trees. But that doesn't necessarily mean they should be laid to waste, says Brian Brashaw, who has helped assemble a handb...

A pile of split birch wood at Price Firewood Company west of Cloquet. Bob King /

As emerald ash borers munch their way ever further into the Northland, one fact seems certain: We're going to lose a lot of trees.

But that doesn't necessarily mean they should be laid to waste, says Brian Brashaw, who has helped assemble a handbook for how to put compromised trees to productive use. Brashaw put together the guide as an employee of the Natural Resources Research Institute in Duluth, though he now works as program manager for the Forest Products Marketing Unit of the U.S. Forest Service.

Northern Minnesota is home to the highest concentration of ash trees in the nation, according to the Forest Service.

While steps can be taken to slow the advance of the invasive beetle and to protect individual trees, nothing yet has been able to hold the infestation at bay.

The first evidence of the destructive insect's arrival in the Twin Ports was discovered in 2013, when damaged ash trees were found in Superior.


After leaping across the St. Louis River, the emerald ash borer made its first foray into Duluth by way of Park Point, where an infestation emerged in October.

As of yet, Park Point is the only part of Duluth to be placed under quarantine for the beetle. But the city is bracing for what looks to be the inevitable advance of the emerald ash borer.

Brashaw said he co-wrote a guide - Wood Utilization Options for Urban Trees Infested by Invasive Species - in anticipation of this very moment.

"We knew that eventually emerald ash borers would get here. And this was intended to provide a road map of all the product options that are out there," he said.

In all, 500 copies of the publication were printed a couple years ago, and they've all been snapped up by people in communities dealing with forests threatened by invasive insects of all kinds, including not only the ash borer but also other destructive pests such as the gypsy moth, the Asian long-horned beetle and the walnut twig beetle.

Although print copies of Brashaw's publication are no longer available, he said the document continues to be offered online, where it has become a popular resource.

Brashaw encourages communities confronting the emerald ash borer to consider how trees that are removed can be put to what he calls "the highest and best use."

At the very least, they can be used for fuel, Brashaw said, noting that many of the ash trees cut in Superior have gone to feed Minnesota Power's Hibbard Renewable Energy Center.


Hibbard has been receiving chipped ash trees from Superior for a couple of years and plans to continue that relationship, said Amy Rutledge, Minnesota Power's manager of corporate communications. She estimated the substation has burned between 400 and 500 tons of the material annually.

While that's one useful option, Brashaw contends: "There are also higher-value uses. When trees are harvested in log form, then you're looking at things like veneer from really high-quality trees. You're looking at saw logs that can be turned into lumber for things like flooring or furniture. Then you're looking at smaller logs that could be used for industrial applications like pallets or crating. All of those have more value."

Even firewood can command a premium if properly processed, observed Victor Krause, a principal scientist at the NRRI.

Ashes to ashes

Krause pointed to operations such as Price Firewood Co. of Cloquet that heat treat firewood for sale throughout the region. He noted that firewood can be certified as pest-free when it is heated to an internal core temperature of at least 140 degrees for a sustained period of one hour.

Kent Price Sr., the proprietor and namesake of the Cloquet company, said wood typically spends eight to 10 hours of time inside a specially designed kiln to achieve the required results in winter.

The kiln is fueled with tree waste deemed inadequate for sale as firewood, but even so, Price figures that heat treating the wood adds roughly 25 percent to his production costs.

Price sells most of his heat-treated firewood through retail businesses in small bundles for campfires.


It's a niche market, but Price said he sells at least 20,000 bundles of firewood in a typical year.

Mark Abrahamson, an entomologist for the Minnesota Department of Agriculture, said there are five state-certified operations like Price's in the state. Each is inspected annually to ensure it is following the proper protocol and can provide ongoing documentation of the treatment process.

Abrahamson said the best time to move and process potentially contaminated wood is during cold-weather months, when the beetle lies dormant.

Price sees no reason why ash from an area quarantined for the emerald ash borer couldn't be treated and safely sold to non-quarantined areas.

"The heat-treating process will kill anything living under the bark," he said.

Nevertheless, Price has generally shied away from dealing in heat-treated ash firewood in recent years. Even though ash burns well and can be rendered pest-free with proper processing, he said the wood carries a bit of a stigma due to the borer scare.

If that can be overcome, Price said he would gladly add ash firewood to his bundles.

Krause said he doesn't believe any of Minnesota's certified heat-treated firewood processors currently are active within quarantine areas.

He explained that none of the existing operations are located within an area where the infestation has spread, and authorities have not allowed potentially contaminated firewood to be hauled out of a quarantine zone for treatment elsewhere.

"At this point, I think they would need to put up a facility within the quarantine zone to be able to treat it," Krause said.

Price said his certified wood can be sold just about anywhere, but he generally operates within 100 miles of his base in Cloquet.

"If we went any further, our profits would be absorbed by transportation costs," he said.

Despite geographical market limitations, business apparently has been good for Price, who aims to ramp up his production of heat-treated wood. In the near future, Price said he hopes to purchase and start up a second kiln at a likely cost of about $100,000.

"People are generally willing to pay a little more for heat-treated wood, because they don't want to be known as the guy who caused the emerald ash borer or some other pest to spread," Price said.

Other markets

Brashaw sees opportunities for cities to tap other wood markets, as well, but conceded there are challenges to overcome.

"Municipalities have struggled with this - Detroit, Chicago and Superior - they've struggled with urban wood markets," he said.

One hurdle has involved harvesting methods. Brashaw noted that trees to be removed from an urban setting, typically aren't as concentrated as what forest industry professionals typically encounter.

Yet Don Peterson, president of Renewable Resource Solutions LLC, said areas such as Kenosha County, Wis., have enjoyed recent success enlisting logging professionals to help remove and market ash trees.

"The big thing that kind of controls the situation is the volume. If you have volume, you can typically find markets," Peterson said.

Kenosha County just finished collaborating with a logger to remove more than 4,000 trees from public property.

"With that amount of trees, we were able to sort out saw logs; saw bolts, which are smaller logs down to 8 inches, that typically will go for pallet lumber; and then the rest of the wood went for either firewood or pulpwood," Peterson said.

There was no market to sell much of the treetop material, but Peterson said: "We did find a mulch supplier that came in and ground them all up for no charge and then took them off the property."

Long story short, the county was able to reduce its costs substantially. While the lowest bid Kenosha County had received from a tree service would have yielded a cost of nearly $100 for each tree removed, Peterson said that by working with a logging company that cost was cut to about $15.50 per tree.

Brashaw said finding markets for trees that must be removed has multiple benefits.

"It does two things. First, it creates better utilization. And second, it creates revenue, because this is an expensive challenge," he said.

Hauling ash

In the case of Kenosha County, the harvested ash trees all went to end users who were within the quarantine zone, simplifying the process.

But Peterson said he also has worked on other projects, such as one in Oak Creek, Wis., that involved moving trees from a quarantined area to an end user outside that zone. One of the keys there involved tackling the work at a time when ash borers lay dormant.

"The saw logs did go outside the quarantine area, but because it was in November, the sawmill had I believe until the end of March to saw them up and get rid of all the material. So it can be worked around," Peterson said.

Similarly, Abrahamson said the Minnesota Department of Agriculture can allow for the movement of wood from a quarantine zone to an end user in an area where the emerald ash borer has not yet arrived, as long as a compliance agreement has been signed, detailing the protocols that must be followed and opening the door for spot inspections to ensure adherence.

Brashaw stressed the importance of partnerships, saying: "Any utilization strategy for ash especially has to be done in coordination with the regulatory folks,"

Abrahamson said the Minnesota Department of Agriculture remains receptive to the challenge.

"As emerald ash borers spread, the discussion will not only be about how to slow it down as best we can but also about what are the good opportunities to use that wood," he said. "It is something that I think is going to need more attention and work in the future."

Brashaw hopes his work will inspire communities dealing with the loss of ash trees will look for ways to market the material.

"It's not easy, but it's possible," he said.


To learn more

Read "Wood Utilization Options for Urban Trees Infested by Invasive Species" here.

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