After the invasionKnowledge gained in other communities could help Superior develop a strategy for dealing with the city’s almost 3,000 ash trees in the wake of the discovery of emerald ash borer in North End.
By: Shelley Nelson, Superior Telegram
Knowledge gained in other communities could help Superior develop a strategy for dealing with the city’s almost 3,000 ash trees in the wake of the discovery of emerald ash borer in North End.
While the larvae of the metallic-green half-inch bug has necessitated taking numerous trees in the city’s northernmost neighborhood, city officials are looking to other communities to develop a course to address those yet unaffected.
It’s one they hope could spare the agony felt in the late 1970s and early 1980s, when the city’s elm population was decimated and a good portion of the city’s green canopy was lost. By the early 1990s, only 52 elm trees remained according to a partially completed inventory of the city’s trees. Today, with planting a disease resistant strain of elm — 80 since 2010 — fewer than 200 can be found citywide.
City officials are hopeful the insight gained in other places can render that kind of devastation unnecessary.
City Forester Mary Morgan, who has been working with the Urban Tree Board several years to prepare for a possible infestation of the bug that originated in China, said she’s learning a lot more since the discovery in Superior.
“I’m learning a lot about this from my urban forestry colleagues,” Morgan said. And she’s planning to present her findings about the invasion and some of city’s options to the tree board at 4:30 p.m. Thursday in Room 204 of the Government Center.
“I’m certainly interested in hearing their thoughts,” Morgan said of the citizen panel that helps manage Superior’s public trees. “I’ll be briefing them on the current status of the infestation. I’ll be discussing the city’s next steps and I’ll be seeking their assistance for a community wide public relations campaign.”
Morgan said her first concern after the discovery of emerald ash borer in North End was the potential for this to turn into a public safety issue.
“I was really wrapped around the idea of having many hundred hazard ash on the boulevards,” Morgan said. However, in researching the issue and trying to find cost-effective solutions, Morgan said she learned treatment — something she initially rejected — may be a viable option.
At a cost of $1 million per year, the city of Milwaukee is finding some success in holding the bug at bay, said Ian Brown, Milwaukee’s urban forest technical services manager. And so far, it’s giving the city of Milwaukee an option that doesn’t include removing 36,000 public ash trees at an estimated cost of $27 million.
The cost doesn’t include the loss of the tree’s value in managing storm water and enhancing the city’s environment, Brown said.
“It’s better and cheaper for us to treat a majority of our trees,” Brown said. He said it allows the city to remove those that aren’t likely to survive or thrive for other reasons in smaller numbers over time.
In Milwaukee, like Superior, ash became a replacement for the dying elm trees decades ago because they have similar characteristics: urban hardy, relatively fast growing with a nice canopy.
Milwaukee began treating its public ash trees — those greater than eight inches in diameter — with the insecticide before emerald ash borer was discovered there. The city is now in its fifth year of treatment. Each year, crews treat half the city’s ash trees, the north side one year and the south side the next.
“This allows us to spread out those removals and replacements over a 20-year time frame,” Brown said. He said the goal of treating Milwaukee’s ash trees is to create “operational leverage” to reduce the risk to public safety and avoid undue stress on the Milwaukee’s urban forestry department.
Milwaukee has had some success with the treatment.
While the city hasn’t had a peer-reviewed scientific study of the treatment program success, Brown said the discovery of emerald ash borer in Milwaukee last year is telling.
“When the city of Milwaukee had emerald ash borer confirmed, it was on private ash trees,” Brown said. “One of our forestry managers had observed characteristic decline and die back on trees ... in the backyard of a private property. In the front yard of that private property, the entire block is city of Milwaukee ash street trees. Those trees had been treated ... none of them were showing any signs of decline.” Other private ash in the area that had not been treated were exhibiting signs of decline as were city trees that had not been treated because they were smaller than the city’s threshold for treatment, he said.
“In my mind that was a very poignant demonstration, Brown said. “What we were doing was working as we had hoped .... there was a very distinct difference between the two.”
Superior’s next step
Morgan is still working to gather information to provide the Superior City Council and public with an array of options to consider as the city deals with the discovery in North End. While numerous trees have already been taken, they are in the area where the discovery was made and exhibited signs of the infestation — die back near the top of the tree and suckering at the base of the tree.
Ash trees have value, Morgan said, adding an average ash tree is worth $1,470 for each year it stands, based on its aesthetic and environmental benefits.
Brown said the trees canopy can slow the impact on storm water overflows, help with erosion, in addition to absorbing storm water and carbon monoxide, and producing oxygen.
The USDA estimates one acre of forest removes six tons of carbon dioxide and produces four tons of oxygen.
One of the things the city is going to want to do is get information out to the public, Brown said. He said that was one of Milwaukee’s strategies after seeing the unscrupulous things some people had done in Detroit — taking advantage of people’s fears —when the city in Michigan was struggling with the infestation. Morgan is planning public meetings in the near future.
Superior isn’t alone in facing implications of emerald ash borer in Superior.
Forestry Manager Jon Harris said the county, which extends almost 55 miles south of Superior, is just beginning to explore its options for managing the state’s largest commercial county forest affected by emerald ash borer.
The actual impact of the county forest on the local economy is unknown, said County Administrator Andy Lisak, who was unaware of any study that had been done on the economic impact of the county’s 280,000 acres of forest.
However, in 2013, county timber sales provided about $758,000 in relief to property taxpayers countywide. It’s a major source of income for the county, which now has 23,000 acres of swamp hardwood facing special regulation and limiting its purpose before it can leave the county, for markets largely in Minnesota.
The nearly $2 million budget of the department doesn’t take into account the potential impact on tourism, jobs from the timber industry or the roll out effect of the forestry department’s income and expenditures on the overall economy.
Since the problem as it is known now is in the city, Harris said one of the things he would suggest is that people from Superior visiting rural campgrounds in the county leave the firewood home.
County campgrounds offer firewood harvested locally on site, he said.
In coming weeks, Harris said his goal is to get experts in the invasion of emerald ash borer together with timber operators to find a solution.
Morgan said she is learning there are solutions for dealing with the waste wood that could turn waste into productive timber.
“We’re going to learn a lot more in coming weeks,” Harris said.