Ash trees are responsible for providing the world with oxygen, shade and baseball bats. However, with an infestation of the emerald ash borer within Union County’s Green Valley State Park, the ash trees in the park are being removed out of concerns for safety.
What is the emerald ash borer?
The emerald ash borer is a wood-boring jewel beetle native to parts of northeast Asia that feeds on ash trees. Females lay eggs in bark crevices on ash trees, and larvae feed underneath the bark of ash trees to emerge as adults in one to two years.
The beetles feed by digging tunnels in the tree, starving ash trees of nutrients and water in the process. The destruction caused by bugs require s immediate attention through either treatment or removal.
“Right now, they’re overwintering as larvae in the trees,” said Green Valley State Park technician Daniel Stull. “Right now they are dormant and in the springtime they will come out and start digging through the trees.”
From Asia to Iowa
First confirmations of the emerald ash borer around Creston were reported in 2013 by the Iowa Department of Natural Resources. Stull said it was believed that the bugs made their way from Asia by means of wooden shipping containers and imported wood.
“There are other counties in the area that have the beetle too,” said Stull. “It has taken over and spread really far.”
Iowa is far from the only state affected by the emerald ash borer. The United States Department of Agriculture reports the ash borer’s first known American presence was discovered in 2002 in Michigan. Since then, 35 states have been confirmed to be host to the beetle.
According to the USDA Forest Service, the feeding habits of the emerald ash borer is responsible for the death of hundreds of millions ash trees across the country. After the insect has infested the tree, the canopy begins to thin. Within a year, over a third of the branches may die. Most of the canopy will be dead within two years.
“The bugs are smart so they work from the top of the tree down,” said Stull. “It keeps the tree alive as long as possible. So they can be in the tree for a while before you even know it. You may not know for a year or two.”
Stull said recent studies have confirmed that the emerald ash borer has expanded its choice of food within Green Valley State Park.
“Very recently the county conservation boards released some new research at one of their meetings that the borer is beginning to spread into box elder trees,” said Stull. “All of our box elder trees are already getting hollow, so we decided that if they are going to be a home for the emerald ash borer we will just replace those trees too.”
Curbing the problem
There are methods of chemical treatment for the trees but the procedure is too costly to save majority of the trees.
“You can treat the tree, but for us it’s cost prohibitive,” said Stull. “They have chemicals they inject into the trunk. Union County is saving a few of their trees this way.”
Green Valley State Park has decided to remove the trees before any potential hazard could occur.
“This is a safety concern,” said Stull. “We have a lot of those ash trees in the campground. They could fall onto campsites or trailers. We have storms that come through every year and we have been fortunate.”
As for the removal, Stull said the park is currently focusing on areas that are frequently trafficked.
“We know we have it all throughout the park,” said Stull. “We have areas that are only ash trees but are away from what we would consider ‘high-use areas’. We are targeting specifically the campground, the picnic area and the beach area. Once we get those areas mostly clear we will start working toward the roads and the trails.”
Removal may seem like the end of the problem, but considering the volume of ash trees within the park it will be no easy task.
“Ash trees, at the time they were planted, were fast growing and hearty,” said Stull. “Of course, sixty years ago they didn’t think about an ash borer from Asia coming over and wiping it out. So the ash trees are about 50% of the trees we have in the campground.”
Due to this, Stull said there will be a lot of open space and less shade. The park intends to plant more trees to rejuvenate the woods with new life.
“We have a camping kickoff weekend the first weekend in May and last year we planted 25 oak trees in the campground,” said Stull. “We are going to continue planting trees. They may not be all oak trees. There are new diseases out there affecting oak trees so it would be a good idea to have a variety.”
Union County residents that would like to utilize these downed trees or willing to cut down their own trees for firewood may contact the park office to be issued a Fuel Wood Agreement. These agreements will not be available for residents outside of Union County to protect against the spreading of emerald ash borer.
“We have distributed 11 fuel wood permits so far,” said Stull.
With tree removal planned to be an ongoing thing, visitors to the park are advised to be cautious and respect closures and work zones.
“Everyone should be aware that we may be closing sections of the park or the campground as we continue to remove the ash trees,” said Stull. “Be cautious if you’re driving through and if there are signs restricting off an area, respect those signs. They are there for your own safety, and even if there is nobody currently cutting a tree there is a chance someone could drive over something and pop a tire.”
For more information or questions please call the Park Office at 641-782-5131 or email the staff at Green_Valley@dnr.iowa.gov.