Middleton is weighing a proposal to cut down more than 2,000 ash trees along its streets and in its parks over the coming years to better control the devastation anticipated by the emerald ash borer.
Across Wisconsin, local governments are trying to figure out what to do about the invasive beetle, which decimates ash trees and was first discovered in the state in August 2008. Middleton’s proposal to remove nearly one-third of its public trees is among the most dramatic.
“It’s not the city’s goal to remove trees,” said Mike Davis, Middleton administrator. “It costs money and it’s not popular. (But) we don’t know of any other option and we don’t want to be reactive.”
Village of DeForest officials removed 40 ash trees last year — more than half of which were dead or in poor condition — and plans to cut down 33 more in fair condition this year.
In Madison there are 19,000 ash trees in public spaces, nearly one-third of all public trees. An Emerald Ash Borer Task Force is developing a strategy to combat the beetle.
“We’re really considering everything,” said parks superintendent Kevin Briski.
Ald. Bridget Maniaci, 2nd District, said last week she’s starting to hear from a few residents concerned about the fate of their ashes and interested to learn the city’s plan for replacing the trees.
“I have full blocks that are nothing but ash trees,” Maniaci said of her Near East Side district.
So far, the emerald ash borer, whose larvae tunnel down through wood just under the bark that supplies the tree with water and nutrients, thereby killing it, has been found in seven Wisconsin counties. Those counties and four others are under quarantine, including Waukesha and Crawford. State officials say the borer eventually will infest Dane County and the rest of the state.
“It is a matter of when, not a matter of if,” Jeff Roe, regional urban forestry coordinator for the state Department of Natural Resources south central region, said of the loss of ash trees in Dane County. “It’s entirely possible it’s here now, it’s just so incredibly difficult to detect early infestations.”
Across the state, many communities are preparing for the emerald ash borer. Such cities as Appleton and Fort Atkinson are removing ash trees before the beetle invasion; once the beetle is found, Lake Delton will be removing ash trees as they become infested; and Milwaukee is treating 36,000 ash trees chemically in hopes of preventing infestation, according to the DNR.
Beetle spreading quickly
The emerald ash borer was first discovered in the United States near Detroit in 2002. Since then it has been found in two Canadian provinces and 14 states.
About 25 million ash trees nationwide already have been lost to the beetle, according to the Wisconsin Department of Agriculture, Trade and Consumer Protection.
In Wisconsin, ash trees are common and make up an average 20 percent of city street trees throughout the state. Forestry officials recommend that no one tree specie make up more than 10 percent of a community’s tree population.
But in Madison, Middleton and elsewhere, ash trees were commonly used to replace elm trees after Dutch elm disease hit decades ago, said Middleton forester Mark Wegner.
“Ash trees are native to Wisconsin, they withstand a lot of urban issues,” he said. “Obviously, the ash trees were over-planted. This provides an opportunity to diversify what we have.”
Cutting trees while they're healthy
In Middleton, Davis is proposing the city cut down its ash trees before the beetle infects them in part because the lumber is more useful while the trees are still healthy. New trees would be replanted quickly once the ash trees are removed, Davis said.
“It can still be used as wood mulch, lumber or as biofuels,” Wegner said. “As soon as the county comes under quarantine it can no longer be transported outside of the county.”
Plus, Wegner said, if all Dane County governments wait to remove trees until they’re already dead, it will take more resources to cut them and there will be a glut of wood products in the area.
Removing ash trees ahead of the borer would allow Middleton crews to remove more than half of the trees themselves and save close to $500,000, he said.
The City Council has approved funding for staff to remove dead and dying ash trees this year, but it has not decided whether to approve Davis’ proposal to remove and replace almost all of the 2,325 urban and 261 park ash trees at a cost of $1.8 to $2.1 million. Up to two-thirds of the proposed costs will go toward replanting trees.
The council likely will take up that issue this fall after city staff has spent the summer informing the public on why preemptive removals are necessary and gathering feedback, Davis said.
“There definitely is some concern that we may become too aggressive in the removal efforts,” Wegner said of the five-year plan.
In addition, Middleton is considering treating a limited number of bigger, older ash trees with chemicals and plant new trees in advance of any removals, he said.
“It’s very progressive,” Roe said of Middleton’s plan. “It’s also very sound and to me, professionally, very realistic for what the community can do and should do.”
'Trees are very valuable'
Briski said Madison has been studying Milwaukee’s approach to injecting trees with a pesticide — looking at how long the treatment lasts and what affect the leaves from the treated trees could have on the environment.
In addition, some level of early removal of ash trees that are stressed, have disproportionate shade, or are under power lines “is certainly part of our consideration right now,” he said.
Fred Mohs, a property owner, developer and resident in the city’s Mansion Hill Historic District, has been treating the ash trees at his home for three years.
“It’s costly,” Mohs said of the pesticide treatment, “but trees are very valuable.”