Divas in Distress

In the understory of a Pictured Rocks National Lakeshore forest stands a cluster of cloned beech. They’re easy to overlook, yet their petite frames carry the hope of their species: resistance to the devastating beech bark disease. Planted last fall, these 18 grafted trees represent the first success in a pitfall-lined journey to preserve American beech on the park landscape.

The native species, with its smooth bark and long life, is a defining component of northern and eastern hardwood forests. At Pictured Rocks and fellow Michigan site Sleeping Bear Dunes National Lakeshore, where the tree can be found across tens of thousands of acres, its nutrient-packed seeds provide food for some 40 species, including turkeys, squirrels and black bears. “It’s so ecologically important,” said Tom Panella, a doctoral student at Michigan Technological University who has been helping lead both parks’ beech restoration efforts for the last three years. “It’s like a foundation tree species.”

Beech bark disease was first detected in 1890 on imported European beech in Nova Scotia. Since then, it’s advanced across roughly half of the American beech’s range, killing 50% or more of the trees in forests from Maine to North Carolina and westward to Michigan, where it appeared around the turn of the 21st century. The infestation begins when a non-native insect, often referred to as beech scale, swarms a beech by the hundreds of thousands. The tiny creatures feed on the trunk, opening wounds that a native fungus exploits. Eventually, the combination can sever the living layer beneath the bark that allows for the transport of nutrients and water, killing the tree. Survivors exist in a compromised state, vulnerable to other pathogens and windstorms. The long-lasting and cascading impacts of beach bark disease led federal forester Mark Twery to label it “one of the most dramatic introduced pest problems of Eastern forests.”

Statistically, about 1% to 3% of beech exhibit resistance to the disease. During one visual survey at Pictured Rocks, just four of 186 beech trees appeared free of the infestation’s telltale white fuzz. As efforts to document scale-less trees at both parks continue, managers are pinning their hopes on these hardy outliers.

“Restoring forest species, it’s a long game,” said Andrew Bishop, Pictured Rocks’ chief of resource management. A restoration ecologist, Bishop noted that the process for beech might not be as protracted as the century-long quest to save American chestnut, but “we’re talking about generations to get to the point where we could actually return beech as the important forest contingent that it was prior to beech bark disease.”

In 2019, staff from Pictured Rocks and Sleeping Bear Dunes partnered with Michigan Tech to pilot a grafting program, the preferred propagation method for increasing the presence of resistant trees on the landscape. The ultimate goal is to create pockets of trees whose flowers and seeds could spread resistant genes throughout the forest.

So far, what they’ve learned is this: Propagating the species can be a real beech. Panella, a self-described “plant nerd” who grew up keeping aquatic plants, not animals, in aquariums, has developed a love-hate relationship with the trees. “They’re just divas,” he said.

The labor-intensive grafting journey starts, counterintuitively, with exposing beech to the very thing that could kill them. 

LeighAnna Seguin, a biological science technician at Sleeping Bear Dunes, explained how she and a few colleagues or volunteers hike out in late summer and use a paintbrush to collect scale eggs off infected trees. “It gets kind of messy,” she said. (By the end of a recent collection day, the hat of one of her teammates had been blanketed by the insect’s woolly deposits.) The eggs are sieved from the jumble of adults and their waxy, fluffy byproducts, and then stored in a refrigerator for up to three weeks until they’re hauled back out in coolers, often for miles, through the woods. “A big part of the work is trying to make sure that our eggs stay healthy and happy while we’re taking them on a field trip to different trees every day,” Seguin said.

The targets of these outings are beech without visible scale. Upon reaching such a tree, the team finds two flat spots on the trunk, cleans off any lichen and then secures around 500 scale eggs against each site using a combination of foam, house wrap, wire and silicone caulk. A full year later, they return, pry off the wrapping and count the number of egg clusters and insects. Seguin, who tracks beech data for Sleeping Bear Dunes, said that of the 47 trees they’ve tested so far, 25 exhibited zero evidence of scale, making them candidates for grafting.

In late winter when the trees are still dormant, Panella ventures out to one or two individuals that withstood the egg onslaught and collects a branch, called a scion, to serve as clone material. Successfully lassoing and cutting down a bud-lined twig some 60 or more feet in the air while navigating deep snow and understory snags requires an arborist slingshot, a rope saw and an abundance of luck. If stars align, Panella said, he hooks the correct branch on the first shot. Sometimes, it takes hours.

Each year, Panella aims to gather enough scion wood to produce about 120 grafts. Though his success rates have steadily improved over the years, grafting beech is not for the faint of heart. His grafting instructor, Scott Rogers of the U.S. Forest Service’s Oconto River Seed Orchard in Wisconsin, told Panella he couldn’t imagine working with a more difficult species. There are more intricate steps, the wood is harder to cut, and the grafts take longer to heal.

A month after each resistant scion has been joined to generic beech rootstock, the foot-tall clones are moved from a temperature-controlled trailer to the university greenhouse, where they are nurtured for about two years. “Moving trees around,” Panella said, “that’s a big chunk of my life.”

Eventually, healthy grafted trees graduate to a carefully selected spot in the park understory, where deer, snowfall and other perils await. Of the hundreds of trees grafted by Panella and the doctoral student before him, only a few dozen have survived to be outplanted in the parks. And, of those, just the 18 planted at Pictured Rocks in 2025 are still living.

Despite the rocky start, the threat of a separate disease and the naysayers who call the tree doomed, Panella said he’s hopeful.  “We’ve kind of ironed out a lot” of the process, he said. “Our trees, they’re just doing a lot better than they have been in the past.”