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Thinking Like a Mountain: Why White Oaks Are in Decline (And How You Can Help)

Bruce Ingram
Outdoor America 2022 Issue 2
Removing invasive understory trees - credit Bruce Ingram

What do cabinet makers, boat builders and Kentucky bourbon distillers have in common with hunters, songbirds and American wildlife species?

The answer: they all depend heavily on the white oak, Quercus alba, one of America’s great hardwood trees. It is arguably the most important tree for those businesses, for many wild species and for sportsmen and women in the eastern United States.

That’s why it is so concerning that this cornerstone species is in serious decline. White oaks are not regenerating as well as they should – there aren’t enough new trees.

This fact – and concern about the health of white and upland oaks – triggered the creation of the White Oak Initiative in 2017. This group of government agencies, wildlife biologists, professional foresters, landowners and businesses focuses on ensuring the long-term sustainability of this critical tree, which can be found throughout the eastern states and as far west as Iowa and Texas.

The Initiative estimates that 60 percent of mature white oak stands contain no seedlings (trees under four feet tall), and 87 percent have no saplings (trees two to four inches in diameter at breast height). Just as troubling is the finding that about 75 percent of white oaks in the U.S. are categorized as mature, or fully grown, which means there is a dearth of trees that will constitute the next generation.

What Do We Have to Lose?

“If we don’t start helping the white oak now, its population will start to decline significantly within the next decade or so,” says Melissa Moeller, director of the Initiative.

“And more extreme declines will happen over the coming decades. We’ve already lost one foundational tree – the American chestnut – from the East’s forests. We can’t afford to lose another one. The presence of the white oak benefits the entire ecosystem.”

But now, other species are replacing the East’s traditional oak-hickory forest, which has been one of the major forest types in eastern North America for as many as 9,000 years. That ecosystem type supports a unique mix of flora and fauna.

In addition to their commercial value, white oaks support many types of wildlife. Their acorns are among the most preferred menu items for deer and turkeys. Even in death, the white oak is beneficial as bears and raccoons use hollow trees as dens and bats may roost in these snags. Songbirds such as tufted titmice and chickadees also nest in the oak’s cavities.

As entomologist Doug Tallamy points out in his book, The Nature of Oaks, the quercus genus is also a top host for hundreds of species of butterflies and moths. Their caterpillars, which feed on oak leaves, provide essential food for many songbirds, including the threatened golden-winged warbler. To fledge a nest of birds like the Carolina wren, the parents must deliver hundreds of caterpillars to their young every day.

Behind the Decline

Moeller says there are many reasons behind the decline of this particular tree, including climate change and invasive insects and plants.

In a forest, oaks compete with many other trees and shrubs. “Oaks need sunlight to regenerate, and the acorns that drop are being shaded out by mid-story species,” Moeller notes. A decreased harvest of soft woods for lumber means a greater number of those trees compete with oaks for sunlight in working forests.

A type of selective logging called “high grading” cuts down the most commercially valuable trees, which are often oaks. That practice can also damage a forest and its wildlife.

Another problem is overly abundant deer populations in some forests. They can damage the understory when too many young trees are eaten. Over-browsing by deer reduces the regeneration of oaks and other important species, which can profoundly change the nature of a forest for decades or centuries.

One of my own efforts to foster more white oaks included logging one section of the forest and leaving as many white and other oaks as possible. This effort was connected to my enrollment of that land in the Golden-Winged Warbler Initiative, a Department of Agriculture program to increase the population of that bird. Fewer oaks means fewer golden-wings and many other species. Which is another reason why Moeller describes the white oak as a foundational tree.

Because of the variety of reasons for the oaks’ decline, there is no single or simple solution, and the first step is public awareness. “We are trying to spread the word that more people need to be proactive about this issue,” Moeller says.

Steps to Help

The White Oak Initiative recommends habitat improvement projects:

  • Cut down or move nearby trees that would compete for sunlight with the white oaks. More sunlight helps the tree grow faster and develop a larger crown.

  • Plant seedlings or acorns to begin a new forest, a process called afforestation.

  • Control deer populations since overabundant numbers can destroy seedlings.

I am constantly looking for young oaks to “daylight” by removing competing trees nearby. I’ve also planted seedlings and placed tubes around young trees to protect them from deer and other animals.

Moeller says individuals or groups can reach out to state forestry and game agencies to determine what specific steps are needed to improve oak populations. Organizations like the Izaak Walton League can help with stewardship projects and outreach to inform the public.

To read about the White Oak Initiative, visit whiteoakinitiative.org.

Top photo: Removing invasive understory trees like autumn olive can help ensure young oaks get the sunlight they need. Credit: Bruce Ingram.

Bruce Ingram, Izaak Walton League member, has written young-adult novels and several books about the outdoors. Email: bruceingramoutdoors@gmail.com.