If you’re in the eastern United States marveling at a tree close to 100 feet tall with limbs that spread nearly as wide, there’s a good chance you’re looking at a white oak. Identifiable by its blocky, furrowed bark and round-lobed leaves, white oak is a dominant species across more than 100 million acres of woodland from Maine to Florida and as far west as Oklahoma.
But while white oaks are abundant today, experts are sounding alarms about their future. The invaluable hardwoods appear to have a regeneration problem: There aren’t enough young trees growing to replace the older ones. “If you’re looking up, you’re seeing plenty of white oak trees,” says Jason Meyer, executive director of the White Oak Initiative. “If you’re not looking down, you’re not seeing the problem.”
To stave off what they say is a significant threat to ecosystems and industries, a collection of state and federal forestry departments, universities, timber companies, wildlife groups, and liquor producers came together in late 2017 to launch the White Oak Initiative. Although some scientists are skeptical that the situation is as dire as Meyer and partners say, the group is hustling to save the towering trees through restoration, public outreach, and legislation.
The lack of white oak saplings became evident in U.S. Forest Service data close to a decade ago, Meyer says. Forest canopies in the East have grown denser over the past century due to fire suppression and reduced logging of less marketable species, and shade-tolerant trees like maples and locusts are now outcompeting oaks. The way things are going, he says, populations will start to decline in the next 10 to 15 years.
Losing white oaks would topple a pillar of eastern ecosystems. The trees can live for five centuries, supporting hundreds of species of insects, birds, and other wildlife. They host more moth and butterfly larvae than almost any other plant. “They’re growing some big, juicy caterpillars that are the main food source for our forest bird nestlings,” says Suzanne Treyger, senior forest program manager at Audubon Connecticut and New York. That includes the Cerulean Warbler, a songbird that prefers to live in white oaks over any other tree. Their populations “have plummeted in the last 50 years,” Treyger says, and habitat loss would only worsen the decline.
In addition to hosting bird buffets of insects and larvae, white oaks also provide a major food source all their own: Thanks to low tannin levels, theirs are the sweetest acorns in the forest, enjoyed by Blue Jays, woodpeckers, Wild Turkeys, and more. Turkey populations are healthier in places with abundant white oak, says Doug Little, the National Wild Turkey Federation’s director of conservation operations in the East. Hens that spend the winter foraging nutritious acorns may lay more eggs in the spring. “The healthier the hen, the larger the clutch size,” he says.
White oak is essential for not only sustaining Wild Turkeys, but also for producing brands like Wild Turkey.
White oak is essential for not only sustaining Wild Turkeys, but also for producing brands like Wild Turkey: By law, bourbons and Tennessee whiskeys must be aged in new oak barrels. The unique cellular structure of white oak means it can hold liquid without leaking, and natural sugars released when the cooper scorches the barrel’s interior are what make whiskey look and taste like whiskey. “White oak is the number one ingredient,” says Barbara Hurt, executive director of Dendrifund, a nonprofit affiliated with distillery giant Brown-Forman, makers of Jack Daniel’s and other whiskeys and a founding member of the initiative.
A mature tree contains only enough wood to make one to three barrels, and the growing popularity of bourbon—the Kentucky Distillers’ Association reports a 465 percent increase in production since 2000—puts more pressure on the supply. Still, barrels are just one of many products made from white oak, and Brown-Forman tells Audubon that it follows forest stewardship plans and harvests timber responsibly.
To forestall the species’ decline, Dendrifund and partners in the White Oak Initiative released a comprehensive action plan in 2021, which helped spur the creation of a Congressional White Oak Caucus, whose members introduced the White Oak Resilience Act to funnel money into research and regeneration projects. The House passed the bill in September and sent it to the Senate.
On the ground in the eastern woods, state and federal foresters and conservationists with organizations like American Forests have already gotten to work. They employ practices like soil scarification (using tools or machinery to tear up the forest floor), selective logging to open holes in the canopy, and prescribed burning. Such seemingly destructive events can in fact benefit the species by creating a nutrient-rich soil bed for seedlings and providing sunlight to help them germinate.
Yet not everyone thinks such interventions are necessary. White oaks may simply be undergoing a lull in their 100-year regeneration cycle, says Harvard ecologist Neil Pederson: “If there aren’t any trees in the understory today, it doesn’t mean there’s a problem next decade.”
All agree that healthy oak forests, like barrels of bourbon, need time to mature. But a wait-and-see approach is risky for those who depend on the species. To protect businesses and birds, white oak advocates say, there’s no time like the present.
A version of this piece originally ran in the Winter 2024 issue as “Making a Stand.” To receive our print magazine, become a member bymaking a donation today.