The discovery of beetle last summer was accompanied by grave predictions that are now coming to fruition as the city struggles to save some trees, cuts others down
The emerald ash borer has continued its relentless path of destruction in Port Washington since it was detected last summer, leaving infested trees throughout the community and pockets of dying ash in its wake.
In what’s likely to become a sign of things to come, a forestry class from Milwaukee Area Technical College was in Port Washington’s Upper Lake Park last Friday, learning to cut down trees as they felled trees infested by the borer.
“It seemed to be a good experience for their students to learn,” city arborist Jon Crain said. “I’m trying to find anything good from this that I can.”
The group took down five trees Friday, and will continue to remove ash trees in the park during winter, he said.
There are more than 250 ash trees in Upper Lake Park, he said, not including those in the ravine. He’s treated about 40 of the trees to protect them from the insect, picking the healthiest trees and preserving shade trees whenever possible.
“I’m trying to make sure we don’t have big bare areas,” he said.
The remainder will be felled over the next several years, Crain said, noting that even if they aren’t showing signs of infestation they are sure to become food for the borer.
“It’s inevitable that they will perish,” he said.
Crain, who has treated about 600 of the city’s ash trees in parks and along streets, said he’s seeing signs of the borer throughout the city.
“It’s all over the community,” he said, estimating the insect has probably been in the city for six or seven years even though it wasn’t discovered until last summer. “I would love to save as many as I can, but I have to be realistic.”
Some of the hardest hit areas are along the bike trail and along Sauk Creek from South Wisconsin Street west to Moore Road, Crain said.
“I can see the thinning in the tops of the trees,” he said. “In the next few years, we’re going to see mortality rates jump from 20% to 70%. It happens quickly.”
Bill McNee, the Department of Natural Resources forest health specialist for southeastern Wisconsin, said tree mortality becomes evident after four years of infestation but after eight years “it really takes off. After 12 years, few ash trees are left.”
While Port Washington is still early in the cycle, he said people need only look west to Newburg, where the borer has likely been present for at least nine years, to see what the future holds.
“Four years ago, you couldn’t tell there was anything wrong,” he said. “Now, it looks like January. Areas with 40% mortality last year, it’s now 100%.”
So far, the borer has been detected in Newburg, the towns of Saukville and Fredonia, Port, the Village of Fredonia and Harrington Beach in the Town of Belgium, McNee said.
The beetle hasn’t been found yet in Grafton, Cedarburg or Mequon, but it’s only a matter of time, he said, noting the borer has been detected to the south in Brown Deer and other parts of northern Milwaukee County.
“It probably is in these other communities, but they just haven’t found it yet,” McNee said. “Southern Ozaukee County is surrounded by these infested communities.”
But because it’s still early in the cycle, Port Washington property owners still have time to treat healthy trees if they want to save them, he said.
In the meantime, Crain is contacting sawmills to see if they might be interested in turning infested trees into lumber. The beetle only lodges in the outer layer of the tree, so the inner wood could be harvested, he said.
“There’s a lot of nice straight wood up there,” he said of Upper Lake Park. “Other cities have made park benches and picnic tables with the wood. It’s just an idea right now, but it would be nice if something good would happen.”
Image Information: A LARGE ASH tree in Upper Lake Park was felled last week by city arborist Jon Crain (front) and Matt Didier. More of the park’s 200-plus ash trees will be taken down in the coming years as the emerald ash borer (left) continues its relentless march across the city. The beetle has infested a number of ash trees throughout the city, and tree mortality is expected to skyrocket in coming years as the insect’s population booms, officials said. Top photo by Sam Arendt, left photo courtesy of Wisconsin DNR