Once a top priority for the city of Abilene, the threat of the emerald ash borer hasn’t gone away.
It’s just stalled.
John Barbur, chairman of Abilene Tree Board, said about half the city has been surveyed and the location of over 100 ash trees the city is responsible for have been identified.
“For various reasons, because of funding and other things and particularly right now during the coronavirus, we haven’t been able to finish that second half inventory,” Barbur said.
An equivalent of 24 days were spent on the first half of the project and the hope is to finish the project next spring.
“We need to know where all the ash trees are that the city is responsible for,” he said. “At that point we can put together the plan on how we address that.”
Barbur said there is no evidence of the emerald ash borer in Dickinson County.
“It is certainly off to the east,” he said. “We know it is in Shawnee County. They haven’t made it official and it could be beyond Shawnee County but we don’t really know that. That is just a guess.
“Everyone is stressed out in a lot of ways. I think we do have some time,” Barbur said. “I am pretty hopeful about this. They are not in our area so we have a little time to work on this, how to prepare for it. It is not an emergency situation.”
However, there needs to be funding to form and implement a plan, he said.
Ten Kansas counties are in quarantine where the emerald ash borer presence has been documented: Atchison, Doniphan, Douglas, Jackson, Jefferson, Johnson, Leavenworth, Miami, Shawnee and Wyandotte.
“The joker card here is that if somebody moves infested wood into our area, we could have it like this next spring,” Barbur said. “But as far as we know that hasn’t happened. It will continue to spread this direction even if nobody moves the insect into our area.”
Based on 16 years of U.S. Forestry Service Forest Inventory Analysis data for 960 counties, Purdue University professor Songlin Fei has shown that in impacted areas, young trees are dying before they can reach their reproductive stages. Unable to compete with larger trees or resist the emerald ash borer, American ash trees may be doomed to functional extinction.
“As we see overstory ash trees dying in these forests, we had hoped that ash would respond to the emerald ash borer like many forests do to fire, regenerating after the fire is gone,” said Fei, a professor of forestry and natural resources and Purdue Agriculture’s Dean’s Chair of Remote Sensing. “What we found is that these ash trees are not surviving. There is more mortality in the small-diameter ash trees than there is recruitment, and few are maturing into large-diameter trees capable of producing seed. In the long run, we will run out of material and no longer have ash reaching the reproductive age.”
Barbur, however, said there is hope for the ash trees to survive the beetles.
He said there are states that have large ash forests where the emerald ash borer has killed trees.
“We don’t know much about it at this point but if you go into the forests there are literally 10 of thousands of ash trees dead. Yet there will be one or two that the borer never even attacked,” he said. “They are trying to do some research on those trees to find out what it is that keeps them safe from the emerald ash borer.”
He said it might be possible to collect seeds or reproduce those trees that the emerald ash borer will not attack.
“It isn’t to say we can’t get the ash back if we can figure out that whole piece,” he said. “There is a lot of research on that right now.”
After the tree dies, in a couple years the tree will decay to the point that limbs will fall off.
“You get a big windstorm, the roots are probably rotted, so they start blowing down,” he said.
Abilene is still in the planning stages of addressing the emerald ash borer.
“We might be able to replant some other trees,” he said. “At this point we don’t have a good alternative on any of the ash trees.”
Barbur said the ash tree that is native to this area is the green ash.
“A lot of people will go to a nursery and buy a white ash tree,” he said. “They also do well here even though they are not native to our area.”
“They are a nice looking tree,” he said.
The emerald ash borer is native to Asia, according to the Kansas Department of Agriculture.
It was first discovered in North America in 2002 in the Detroit, Mich., area. Since then, it has killed millions of ash trees and caused thousands more to be removed to slow its spread.
Its western range has reached South Dakota in the north down to Texas in the south. It’s in every state east of that line except for Mississippi and Florida.
Its larvae burrow under ash tree bark to feed, eventually weakening and killing trees, with losses estimated in the tens of millions so far.
According to Fei’s findings, which will be published in the January issue of Forest Ecology and Management. “This trend suggests that ash will continue to decline in abundance and may become functionally extinct across the invaded range of emerald ash borer.”
Fei cautioned that the results do not suggest that ash trees will disappear altogether from the U.S. However, being functionally extinct means that they will not provide economic value as hardwoods or the ecological services they long have in forested areas.
“Like elm, which was decimated by Dutch elm disease, there may be places with ash trees and seedlings in the understory, but they won’t mature in populations large enough to fulfill their traditional economic or ecological purposes,” Fei said. “There also are peripheral areas that haven’t been invaded by the emerald ash borer yet. In those places, we still have a chance and we do want to fight there to keep those forests safe.”
Ash trees in residential areas can be treated with insecticides to keep emerald ash borers away.
Contact Tim Horan at firstname.lastname@example.org.