This story comes from WVIA News.
This story is part of our series, Wild Pennsylvania. Check out all of our stories here.
Beech trees are facing extinction.
“When you say northern hardwood, that is, to a forester, that is the tree you think of, it’s beech trees,” said Pat McElhenny, Pennsylvania Stewardship Manager at The Nature Conservancy. “But to think that it could be gone in x number of years, hard to believe.”
The native Pennsylvania trees are being attacked by two separate diseases — beech bark disease, which moves very slowly, and beech leaf disease, which is rapidly deteriorating the trees’ population.
- A section of Clear Creek State Forest is recognized as old growth
- How a land trust is fighting invasive hemlock woolly adelgid in Allegheny County
The former is caused by a fungus and makes the trees’ smooth, almost-gray bark flakey. The tree panics and sprouts up little trees all around it, called beech brush.
“It’s like a defense mechanism because it’s being stressed … as an adult, you’re trying to figure out do I produce acorns? or do I produce whatever it is that will give me more young?” McElhenny said.
Beech bark disease has afflicted the trees for about 100 years.
Pat McElhenny, Pennsylvania Stewardship Manager at The Nature Conservancy (TNC), stands next to a beech tree battling beech bark disease at TNC’s Long Pond Preserve & Hauser Nature Center. Photot: Kat Bolus / WVIA News
Beech leaf disease is the death sentence. For the past 12 years, tiny microscopic worms called nematodes have been eating away at the cell structure inside the leaves. The tree then produces less food for itself.
Ben Chase, conservation forester at The Nature Conservancy, says one study showed that the nematodes reduce photosynthesis by 60%.
“If the tree had resources into creating these leaves, and it’s not able to get that energy back through photosynthesis, it’ll start to starve and go through its stored energy, and eventually the tree will die,” he said.
McElhenny walked through a forest at the Nature Conservancy’s Long Pond Preserve and Hauser Nature Center in the Poconos.
“You’ll look up through the light, and you’ll see a lighter color of green and then you’ll see these dark stripes” on the leaves, he said.
McElhenny said the combination of diseases is a “double whammy.”
“This is going to push it over the edge,” he said.
Beech tree extinction will upset the forest ecosystem in Pennsylvania, said Chase. The nuts the trees produce are an important source of food for turkey, bears and deer.
“They produce these in the fall, and so going into the winter, it’s really important for wildlife to get these fatty, calorie, dense food sources like Beech nuts or acorns,” he said, adding certain insects feed on beech exclusively.
Losing beech changes the forest’s canopy, said McElhenny. The forests are thinning out.
“Living in the Poconos, where I travel, seeing the results of it so quickly, has just been like, just overwhelming,” he said.
A map showing the spread of beech leaf disease by December 2023.
Not a cure, but management
Chase said researchers are at the stage where they’re looking at how long it takes the trees to die.
Penn State’s College of Agriculture Sciences is researching the disease as well as other universities in the Northeast, said Vincent Cotrone, an urban forester and natural resource educator for Penn State Extension.
“Most of the damage is being done before the leaves even emerge. So they’re feeding inside the buds,” Cotrone said about the nemotodes.
Treating the single backyard beech is much easier than a forest full of them, he said.
Cotrone said potassium phosphate, which is a fertilizer, can help boost the tree’s immune system.
“It doesn’t cure it, but it improves the plant’s conditions,” he said. “It takes time and research before you start to find a potential, I’m not going to say cure, but management, to keep the nematode in check.”
Chase described losing beech trees as playing Jenga.
“Everything becomes a little bit less stable,” he said. “For Pennsylvania, the speed at which this is moving is outpacing a lot of the science around it.”
For more resources on beech bark and leaf diseases, visit https://extension.psu.edu/guide-to-beech-leaf-disease-for-the-public.
