As Diseases Ravage Ohio's Forests, Not All Trees Are Sure To Survive

Sep 7, 2017

The mayor of Akron recently issued a warning to citizens to be on the lookout for a fungus that kills oak trees. Oak Wilt is a condition that affects red oak and pin oak trees and has been found in the city. But it’s only one of the scourges that could spell doom to trees in Ohio.

You can start in northwest Akron where tall oak trees line both sides of Palisades Drive, creating a cathedral effect of leaf canopies overhead. City of Akron arborist Jon Malish stands next to one with almost no leaves left. It’s dying of Oak Wilt.

“This was a three-week process,” Malish says. “Three weeks ago we noticed one branch had brown leaves on it. Nothing had fallen yet but as you can see in the canopy there is practically nothing is left.”

How dangerous is it?

“It’s pretty deadly,” Malish says. “Anything in the red oak group – red oak, pin oak, black oak – once they are infected there’s really not anything we can do for it. White oak group has some resistance built to it. The only thing we can do is preventative measures with fungicides.”

Malish says residents can do that for their own trees, but the city won’t try it on city property.

“No, it’s quite expensive,” he says.

Malish wants residents to avoid pruning red oak trees between April 1 and October 1 because the beetles and fungus can infect the wounds during the warmer months.

A healthy red oak on the left and an oak dead from Oak Wilt on the right.
Credit Mark Urycki / ideastream

Oak Wilt was first found in Wisconsin in 1944.

But Northeast Ohio is ground zero for a more mysterious disease that’s been killing small beech trees, the ones with silver smooth bark on which people love to carve their names.

You can see it at Hell’s Hollow Wilderness Area in Thompson.

Lake County Metroparks’ biologist John Pogacnik points to the shriveled leaves with dark and light green. 

“It’s just a little darkening in between the veins of the leaf,” Pogacnik says. “That gives a striped appearance.

What’s causing that?

“That, we don’t know,” he says. “I found the disease in 2012 and that year we had a drought so I thought it may be drought-related."

The neighborhood around Palisades Dr. in Akron is graced with 75% red or pin oak, all susceptible to Oak Wilt.
Credit Mark Urycki / ideastream

Pogacnik called in some experts from the U-S Forest Service

“The weird thing about the Beech Leaf Disease is that we checked all over the world where they have beech and no one else has ever seen anything like it,” Pogacnik says.

So Pogacnik wasn’t just the first to see it in Ohio, he was the first to see it anywhere in the world. Does that mean it’ll get the name Pogacnik’s disease?

“Heh, Beach Leaf Disease so far,” he replies. 

The experts suspect a virus causes the disease. Pogacnik believes extreme weather in recent years is putting stress on trees, making them weaker and more vulnerable. 

One thing he knows is Beech Leaf Disease is spreading rapidly.

Dark and light green stripes is the tell-tale sign of Beech Leaf Disease.
Credit Shane McKeon / ideastream

“At Chapin’s Forest one year, 20 percent had some stage of the disease, the following year 70 percent, and now 100 percent,” Pogacnik says. “In three years it spread that quick.”

He doesn’t think large trees can shake it off, either.

“It looks like it’s going through them and right now we don’t know anything about it,” he says. “We just see it getting worse and the general thought is it will kill them eventually, but we’re hoping that’s not the case.“ 

Pogacnik fears that within 10 years, Northeast Ohio will have no beech tress left.

Lake Metroparks biologist John Pogocnik fears that hemlocks and beech trees may be gone from Lake County forests in 10 years. Sugar maple trees are also facing an uncertain future due to earthworms.
Credit Shane McKeon / ideastream

Beech Leaf Disease has spread as far south as Stark County already, but it’s moved particularly far east, into Pennsylvania and almost to New York State. That leads to speculation it’s carried by insects that get blown in the wind. 

The thought of a major tree die-off brings to mind the American Chestnut Blight, which came into the U.S. from Japan in 1904. By 1940, virtually all the mature chestnut trees - as many as 1 billion - were dead.

But there is some good news. In some newly acquired woods of the Portage County Park District, one mature chestnut was found. The Park’s Natural Areas Steward Bob Lang says park officials were hiking the property just after they bought it. 

“We just happened to look down and notice some burrs on the ground,” Lang says. “I thought ‘Boy, that sure looks like American Chestnut.’ And sure enough we all looked up and there it was.”

Portage Parks steward Bob Lang came across a rare mature American chestnut tree in newly acquired park land.
Credit Mark Urycki / ideastream

The tree is about 18 inches in diameter, maybe 30 feet high. Lang points out it appears to have some blight damage on its lower bark.

“It’s trying to heal over that,” Lang says. “And that’s where some of the debate was that, ‘Boy, maybe it has actually trying to fight that off, it has some perhaps resistance.’ But it’s started to heal over that wound.”

So they’ve treated it with a fungicide to help it.

“If we can get it pollinated this will be a source of viable seed for the 100 percent true American chestnut,” Lang says. “And for just that I think it’s worthwhile in this case to try and take care of this tree.” 

Few people get a chance to look up at leaves from a mature American chestnut tree, like this one in Kent.
Credit Mark Urycki / ideastream

Scientists are trying to cross breed or genetically alter surviving chestnut trees to be resistant to the blight.

Many of the pathogens affecting Ohio trees came from invasive species or insects imported from other countries. Because of them and global warming, biologists expect Ohio forests will look a great deal differently in the coming decades.