Janesville begins fighting ash borer, but some question plan

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Marcia Nelesen
Thursday, April 4, 2013

— Some Janesville residents were shocked recently to see large, healthy ash trees felled in city parks as a pre-emptive move against the emerald ash borer.

The city’s parks director said he is following advice of state officials to be aggressive—even with healthy trees.

Two local certified arborists, though, said the city chose the wrong trees and should have waited to do anything until after a forester is hired and an inventory of trees taken.

An Ohio expert says new studies suggest cities might consider a greater use of insecticide to save more trees.

Janesville arborist Dave Graham, owner of D.W.G. Co., said taking a tree inventory would be time-consuming but would help the city evaluate the value of its urban forest. Trees are valued for their stormwater remediation, temperature moderation, capture of carbon dioxide and beauty, experts say.

Graham said he was “borderline shocked” and saddened when he saw the trees cut in Upper Courthouse Park.

Chris Ranum of LP Tree Service said Traxler Park looked like a slaughter had occurred.

The emerald ash borer was discovered on Janesville’s east side in June. In infected trees, tunnels excavated by feeding larvae destroy the tissues under the bark, effectively starving the trees of water and nutrients.

City Parks Director Tom Presny said several trees cut in Upper Courthouse Park showed insect damage but not from the emerald ash borer. Others were growing into utility lines.

Graham countered that the trees could have been pruned.

“Ash trees can last for almost 100 years, and those trees weren’t even half their age,” he said.

“I think they jumped the gun, especially because it is a very visible location. Certainly this decision could have waited six months,” Graham said.

The city council approved money in the 2013 budget to hire a forester.

“It wouldn’t be a huge expense to keep some of these trees alive,” Graham said, noting city workers could get certified with pesticides to lessen the cost.

Ranum agreed.

The city should start cutting trees near hot zones, he said, adding there is plenty of time to cut down a tree once it shows signs of infestation by the insect.

Ranum questioned the timing of the cutting, noting the soft ground and resulting mud from heavy vehicles. That will have to be repaired in summer, he said.

‘Testing ourselves’

Presny said he appreciates such queries from residents.

“Right now, we’re just testing ourselves about what we’re capable of and (asking), ‘Are we making good decisions?’” Presny said.

Whether a tree should be cut or saved could be up for debate, he acknowledged.

Presny’s goal is to cut 100 ash trees this year. The intent is to concentrate on older or damaged trees, he said. The trees in Traxler Park were old and failing, he said.

“I guess the biggest point that’s been driven home to me is, ‘Be proactive, get engaged as soon as possible.’

“If you don’t, this problem just sneaks up on you, and the tree quantities become overwhelming.

“We’re starting from ground zero,” Presny said, adding the city is behind because it does not have a forester and does not have an inventory of trees.

Presny said he has had lots of input from the state Department of Natural Resources.

“It’s what we believe is the reasonable course right now,” he said.

“A lot of what we’re doing is about educating ourselves and the community,” Presny said. “Perspective from the community is a good thing.”

The city owns about 15,000 ash trees. About half are in natural areas and will not be a priority.

About 80 ash trees have been cut since January, said Cullen Slapak, assistant parks director. Those were in greenbelts; in Monterey, Traxler and Upper Courthouse parks; at Lions Beach; and in Columbus Circle. None had the bug.

‘Delay is usually regretted’

Mark Guthmiller, forest health specialist with the DNR, said the insect could be in a community three to five years before it is identified. It spreads about a half mile per year.

Each community handles infestations differently, Guthmiller said.

Some treat trees with chemicals until they can be removed to spread the cost of removal over several budgets. Others cut trees pre-emptively. Others cut trees as they die.

“Budgets can be impacted by the volume in the outbreak phase,” Guthmiller warned.

“If you were to visit with one of the urban foresters who work more directly with the community, (you would likely) find that (any) delay is usually regretted,” Guthmiller said.

Dan Herms, an entomologist at the Ohio State University, said recent studies suggest the expense of treating trees could be worthwhile when compared to the cost of cutting them combined with the value of the benefits they provide.

Herms said that initially the slow spread of the bug lulls people into thinking it could be controlled.

“Once the population builds up, the trees start dying really fast.

“It might take 10 years to get to that point and boom!” Herms said. “All of a sudden, it just sneaks up and clobbers you over the head, and it’s too late to react.”

Trees started dying from the bug as early as 1994 in Detroit, which is considered the entry point of the infestation, Herms said. The insect was discovered in 2002. By 2004, 20 percent of the trees were infected. By 2009, 99.7 percent of ash trees were infected, he said.

Now, the bug has been found in 16 states.

“An integrated program can call for protecting some (trees) and not others,” Herms said. “If you’re not going to protect others, then it makes sense to start a pre-emptive removal so it can be done within a schedule and with resources budgeted.”

In Toledo, Ohio, all untreated trees are dead, and the emerald ash borer population is at low levels.

“That’s our next wave of research,” Herms said. “Based on what we’re seeing, we think we can dial back and make the treatments cheaper.”

Scientists are also experimenting with biological controls to battle the bug.

Herms also recommended the city do an inventory, calculate the value of what it has and the future cost of protecting that value.


Last updated: 10:29 am Tuesday, July 2, 2013

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