Has Rochester lost a lot of trees in 2023?
Jul. 31—Dear Answer Man: I've noticed that there seem to be a lot more dead and dying trees around town this spring and summer than in other years. Many of the big trees surrounding the former IBM building were recently removed because they had died or were dying. And all around town I see lots of trees that have died as well. This seems to have started before the drought set in, so I don't believe that is the cause. Do you know why there seem to be so many more dead trees this year than in years past? — Tree Observer.
Arbor Observer,
If you also have a bird-watching hobby, you can sort of kill two ... oh, never mind. Maybe that's not the best folksy aphorism to complete that sentence. Of course, it's not necessarily the lack of water that's been a detriment to trees in our area. In fact, it's that old bug-a-boo (literally), the emerald ash borer beetle.
Jeff Haberman, the forester for the city of Rochester, said while the drought this summer — June's precipitation total was 4.01 inches below normal, and July's will probably be fairly dry as well — generally is affecting young trees, and trees that have girdling roots, the bigger problem is the EAB. That invasive species from northeast Asia is a pest because the ash trees that are native to North America have no natural resistance to the EAB.
While the city has
protected more than 4,000 ash trees
from the EAB using chemical treatment to protect trees on city property, those not treated are still at risk to the insect. That includes ash trees on private property.
"We have marked a lot of dead ash trees this year," Haberman said. "The city is considered generally infested with EAB, and we are now at the point where most ash trees that are not chemically treated as succumbing to the insect."
Ash trees that have been killed by the EAB can become brittle, and are considered dangerous since large limbs or the whole tree can fail at any given time. Dead ash trees on private property are getting marked by the city so property owners can have the trees removed as soon as possible. The longer a property owner waits, Haberman said, the more expensive it becomes.
The city started managing the ash tree population in Rochester in 2016 when the first EAB was found here. On average, the city has removed about 1,000 public trees a year. While EAB is a big culprit, other arboreal issues include Dutch elm disease, oak wilt or trees that simply have structural flaws that make them likely to fail, Haberman said.
And the tree threats keep coming. Haberman mentioned the Asian long horn beetle, which is a threat to numerous tree species, including maple trees. The invasive bug is as close as Illinois.
"For this reason, we encourage people to consider planting other species," Haberman said. "Tree diversity is the ultimate protection from these types of issues, so when something shows up that can take out a species, we do not lose entire block of canopy cover."
So, my tree-watching friend, it seems your observational skills are on the mark. This has been a bad summer for trees, but the city is doing its best and working with local property owners to try to get the problem solved. With luck, these shady threats to our shade trees will be minimized and the city can turn over a new leaf in its fight against arboreal pests.
Don't let your questions fall to invaders. Seek help and send questions to Answer Man at
.
