An eight-year-long goodbye to ash trees in Minneapolis will start up in 2014, as the city begins a $9 million project to take down 40,000 ash trees in the city’s parks and on its boulevards and golf courses.
Armed with a just-approved tax levy specifically designed to blunt the impact of the deadly emerald ash borer, foresters will remove 3,000 ash from city boulevards, parks and golf courses in 2014, and possibly up to 5,000 for each of the following seven years. About 20 percent of all Minneapolis trees are ash.
“It will look different,” said Park and Recreation Board President John Erwin, noting how the urban forest will have more types of trees than it does now, which is due to a historic reliance on a few popular species. That approach left the tree population vulnerable to mass die-offs due to bugs and diseases.
“It’s a very good thing,” said Erwin, a University of Minnesota horticulture professor. “We’re never going to have this situation again that we’ve had with Dutch elm or the emerald ash borer.”
Once the trees are all down, the only ash trees left will be the few on public and private property that either have been chemically treated or have somehow managed to avoid being infested by the tiny green beetle that has spread largely unchecked across North America for 20-plus years, killing every untreated ash it has met.
Ralph Sievert, head of forestry services for the Park Board, said the removal-and-replacement plan is built on the idea that ash trees are, for now, a doomed species whose demise can be managed, economically and aesthetically.
“That’s all assuming the beetle doesn’t go crazy and start killing a lot of ash all at once,” he said.
The levy backing up the canopy replacement plan will kick in Jan. 1 and generate about $1.1 million per year. It will cost the owner of an average-value home $8 each year, Erwin said. The Park Board has removed nearly 5,000 ash trees from boulevards, parks and golf courses since 2010, using its existing funds.
The special tax levy will have to be renewed each year. A Park Board committee last week approved it as part of its overall $66 million budget for 2014, which represents no increase in the board’s operating fund, but it does include $1.1 million specifically to remove and replace ash trees on city boulevards and in parks and on golf courses. The budget is expected to get final approval on Wednesday at City Hall.
Despite the number of trees coming down, Erwin and Sievert say that the plan isn’t exactly clear-cutting.
The Park Board already clears away 5,000 trees of all species in an average year. Ash removals could approach 5,000 in future years with the new levy, but foresters will cut no more than 20 percent of any block’s trees in one year and will go after other ash trees that are damaged or in locations where they wouldn’t grow well anyway.
In 2014, removals likely will be concentrated in the eastern part of the city, where infestations have been detected, and move west, Erwin said.
Sievert said that if residents ask that an ash on public property be removed so a replacement can get started, foresters will take it out and replace it with another species.
Treat or cut?
Residents also can arrange for ash trees on boulevards and in parks and on golf courses to be treated with insecticide, although that requires hiring a Park Board-approved company to do the injecting.
Those residents — not the Park Board — would then be on the hook for continuing treatments costing $150 to $250 every other year. Sievert said about 75 ash were treated citywide with insecticide this year.
Ash trees on private property are the responsibility of the property owners. Sievert said property owners can either let the ash die over time (while planting replacements in the meantime), have them treated, or have them removed and replaced — although not with maple, he said, since that species is becoming too common across the city.
The Park Board won’t follow the insecticide strategy itself, said Sievert, citing emphatic public opposition to the use of insecticides, even though one type has been found to be effective and is getting cheaper. One tree company went so far as to commission a poll that found support for using insecticides in Minneapolis ash, but Erwin criticized the poll’s questions as misleading.
Milwaukee is treating all of its public ash trees under a program that city forestry services manager David Sivyer says has been both effective and economical. At the same time, Sivyer echoes Sievert in saying the program is designed to “put the loss of ash on our schedule.”
“We never envisioned a treatment program that would last 20 or 40 years,” Sivyer said. “We have always thought this would be a gradual transition” toward the ultimate disappearance of ash in the city, he said.
The Minneapolis levy also will fund removal and replacement of trees damaged by storms. The 2011 Minneapolis tornado wiped out 3,200 trees, which cost $1.9 million to clean up and replace. Another 3,000 were damaged or destroyed in storms last June.
By the time those trees are replaced in 2014, that price tag will be about $2.3 million.
In St. Paul, a similar pace
St. Paul will remove about 1,100 ash in 2014 under a program that — with funding from a variety of state and local sources — will remove progressively more trees each year, but ultimately will leave the city with about 5,000 treated ash trees.
Since 2009, the city has treated about 800 trees and removed about 5,000, said Cy Kosel, forestry supervisor for the Parks and Recreation Department. The first to go are those less than 10 inches in diameter (less conspicuous when absent) and those more than 20 inches in diameter (not long for this world).
When there are only 5,000 left, Kosel added, the game likely will have changed, with fewer trees possibly providing less nursery space for ash borer reproduction.
Ash trees within 15 miles of any known infestation are considered vulnerable, according to the Minnesota Department of Agriculture.
Minnesota as a whole has just under 1 billion ash trees, the most of any state in the nation. Ash comprises 7.2 percent of the trees in the state’s forests, but 15.1 percent in communities.