A disease is affecting Canada’s mature beech trees

Updated: May 2, 2019

beechnut-and-pericarp-cover-in-foliage Hartmut Goldhahn/Shutterstock

Think of them as the “avocado toast and eggs” of the forest. Beechnuts—those tasty high-protein, fat-laden favourites of everything from black bears to blue jays—could be increasingly rare thanks to a disease that’s virtually wiping out Canada’s mature beech trees.

Beech bark disease isa one-two punch combining an attack from a sap-feeding scale insect with a subsequent fungal assault beneath the beech’s thin, silvery bark. The disease arrived in the Adirondacks in the mid-60s, and was first recorded in Ontario in 1999. Now, the disease “has gone through the entire range of beech in Ontario,” Greifenhagen says. Among the hardest-hit are big beeches in Ontario’s prime cottage country, from Georgian Bay over to the Ottawa River. “In the worst-hit areas, we’ve seen 70 to 80 per cent mortality over ten years,” Greifenhagen says.

Beech bark disease is bad news for tree lovers, harvesters of firewood, and anyone with a road, trail, or structure near a diseased beech, since the big trees have a habit of rotting inside and snapping off in wind or ice storms. Worst off, though, might be the 40-odd species that use the tree for food or habitat. Beechnuts have almost twice the protein and more fat than acorns, so though beech trees only produce big crops every two to four years, those nuts are a cause for feasting.

But while scientists in the U.S. had predicted beechnut production to fall by almost 30 per cent, it seems the trees in New York State haven’t read those forecasts. As big beeches die, smaller trees are suckering up from the roots of those giants. And, for now at least, the forest’s nut output looks to be higher, not lower.

It’s odd, says McNulty, because a beech tree that grows from seed doesn’t produce nuts for 40 to 60 years, yet these immature suckers are already forming nuts.

McNulty’s “informed conjecture” is that these fertile sprouts may be  supported by mature beech root systems and an extensive subsurface fungal network. According to McNulty, “The suckers and beech trees may be communicating underground via root and (fungal) hyphae networks and sharing hormones, carbohydrates, and/or other resources necessary for reproduction.”

The result, in New York forests anyway, is “nut production continues to go up on our long-term plots, despite the continued persistence of beech bark disease even in smaller tree size classes.” It’s a hopeful sign that woodland creatures may—may—be able to brunch on the forest version of avocado toast and eggs for decades to come.

Featured Video