Visitors to the Chain of Lakes will see temporary trail closures and fewer ash trees this summer.
The Minneapolis Park and Recreation Board is in the sixth year of an eight-year plan to combat the emerald ash borer by removing some 40,000 ash trees on public land and is in the midst of removing about 1,000 ash trees from the Chain of Lakes Regional Park this summer.
The cutting in the Chain of Lakes Regional Park, which includes parks and parkways surrounding and connecting the water bodies from Brownie Lake to Lake Harriet, comes as the MPRB shifts its efforts combating the emerald ash borer into the woodland portion of the urban forest, according to sustainable forestry coordinator Philip Potyondy. The MPRB considers un-mowed grass areas around the lakes as woodland.
Pedestrians enjoying the paths around the lakes have likely seen temporary area closures in recent weeks and those are likely to continue throughout the summer. Potyondy said the crews have worked to make path blockages temporary and asked that people give the workers a wide berth.
In a presentation to the Park Board on June 26, Minneapolis tree advisory commission chair Peggy Booth said the city is continuing to lose trees, largely due to the emerald ash borer, an invasive green beetle that destroys ash trees.
The disease was first found in the city in Prospect Park in 2010 and rapidly spread. In 2019, the disease has been found in 10 new neighborhoods, according to the tree advisory commission. West Calhoun is the only Southwest neighborhood without recorded cases of EAB, though Potyondy suspects there are likely infested trees in the neighborhood.
The Park Board’s ash canopy replacement plan is working, Booth said, but trees on private property continue to be an issue. The commission is advocating for a program allowing property owners to spread the cost of tree removal over several years on their property tax payments. The replacement plan is funded through an annual $1.2 million levy that first passed in 2018. The tree advisory commission has asked the Park Board to pass it again in 2020.
Before EAB there were 1 million trees in the city, about 200,000 of which were ash trees, according to the commission. Of those ash trees about 40,000 were in public parks or boulevards.
By the start of 2019, 28,000 of those trees had been removed and replaced with about the same number of trees of different species. This year, the MPRB has planted about 9,000 new trees in the city with a focus on species diversity to make any future invasive species less damaging.
When ash trees die, they break down and can collapse easily, Booth said.
“When they fall, they’re going to hit something,” Potyondy said.
More than 70% of the 1,000 ash trees being removed from the Chain of Lakes are under 12 inches in diameter at breast height, or about 4.5 feet off the ground, Potyondy said. But some are quite large. The largest tree being removed is about 39 inches in diameter, he said, one of only five ash trees over 30 inches in diameter in the Chain of Lakes. Ash trees are spread throughout the regional park, with high amounts in William Berry Woods and along the Como-Harriet streetcar line.
“It’s what we need to do to mitigate the hazards that are out there,” he said.
Images courtesy of the Park Board.