City prepares for emerald ash borer
Officials say matter of when, not if, bug comes to Marshfield
By Adam Hocking
MARSHFIELD — Staff from the Marshfield Street Department say it is only a matter of time until emerald ash borer (EAB) will make its way to Marshfield.
The website emeraldashborer.info, which “is a collaborative effort of the USDA Forest Service and Michigan State University,” defines EAB as an “exotic beetle” whose larvae feed on and kill ash trees. Through feeding on the ash tree, the larvae impair “the tree’s ability to transport water and nutrients.”
EAB was initially found in the United States in Detroit in 2002 and has spread throughout much of the country since. The spread occurs, at least in part, through the movement of ash tree wood from infested areas to previously noninfested areas.
What the city is doing about it
Though EAB has not yet come to Marshfield, the city’s parks and recreation and street departments are being proactive in defense against a potential infestation. The city recently approved the addition of a seasonal forestry technician that can assist in measures to both prevent and treat against EAB if and when it arrives. The cost of adding that staff person, which the street department and parks and recreation department will share, falls within existing 2016 budgets for both departments.
In addition to hiring the technician, “The city of Marshfield’s EAB response plan includes preemptive ash tree removals, select ash tree treatments, and new tree plantings,” wrote Parks and Recreation Director Justin Casperson in a memo to the city’s finance, budget, and personnel committee in March. Those “new tree plantings” will include new species of tree not thus far susceptible to EAB.
“Implementing an EAB management plan is similar to why you would replace your shingles on your house prior to leaking through the shingle. It’s preventative maintenance so that we can start to get a head start ourselves internally, not only on removals but also replacements,” Tim Rasmussen of the Marshfield Street Department said.
In early April the Wisconsin Department of Agriculture, Trade and Consumer Protection announced that Wood County would be quarantined, forbidding “ash wood products and hardwood firewood from being moved to areas that are not quarantined.” The quarantine came after EAB was discovered in Stevens Point. On May 4 The Wisconsin Department of Natural Resources said EAB had been found in Wisconsin Rapids, the insect’s first appearance in Wood County, according to the Wisconsin Rapids Public Works Department.
“It’s more of a matter of when, not if,” said Rasmussen in regard to EAB reaching Marshfield.
The street division has removed 192 of 410 of terrace ash trees, and the rest are listed as good candidates for treatment. Terrace trees are those between the edge of a person’s property line and the curb of the street.
“The 192 trees removed were trees in conflict with overhead utilities or small in diameter which held very little environmental impact,” Rasmussen said.
The street division manages terrace trees, while property owners control ash trees on their own land, and the parks and recreation department handles the city’s park trees. Casperson said approximately 350 ash trees are in the city’s “managed” park areas, places where people congregate and the grass is cut. The seasonal forestry technician will help the parks and recreation department identify which ash trees are good candidates to be removed versus treated.
Casperson said terrace trees are generally attended to before park trees because they are in high-traffic areas and are more potentially dangerous if they die and could subsequently fall.
He added that the parks and recreation department does not currently have enough money in its operational budget to study the 350 ash trees and would need to request additional funds from the city at some point. Casperson does not have a figure for the cost of treating or removing those 350 trees as his department still needs to analyze the ash tree inventory.
“We’ll eventually have to go to the council and let them know what we need for additional funds. … Our current operations cannot absorb the amount of work that’s going to need be done to treat, replant, and remove every ash tree,” Casperson said.
“The council understands that we’re going to need help once the bug gets here,” said Street Superintendent Mike Winch.
For treating ash trees, the street division is exploring a method where every other year the tree’s trunk is injected with a substance, which prevents the tree from becoming infected with EAB. The street division is also exploring a partnership with Mid-State Technical College where students in forestry classes would plant new trees, saving the city labor costs and providing students hands-on experience.
The cost of EAB and value of trees
Rasmussen said significant tree removal, without a plan to replace them, would cause increased demands on the city’s stormwater system or the need for additional holding ponds.
“One big thing that a lot of people don’t realize is the simple amount of rainfall interception (a tree) provides,” Rasmussen said. “Rainfall interception of just the 410 ash trees that we had was nearly 800,000 gallons annually.”
Casperson has experience dealing with EAB dating to his time working for the city of West Bend, Wis. He detailed some of the reasons trees are important to a city.
“No. 1, aesthetically, people would much rather move into a neighborhood that has mature trees than no trees. No. 2, environmentally, whether it’s water control — helps with water runoff, pollution — so it helps with air quality, noise pollution. It buffers noise, whether it’s road noise or neighbor noise or construction noise, whatever it might be,” Casperson said.