That’s true for Ed and Kathy Rossman, who live just west of Tulsa. They invited Emily Oakley out to their home to determine the age of their trees. Winter had bared all the post oak’s twists and turns. Oakley and her entourage crunched through their shed leaves as they picked the best ones to survey.
“I was thinking the one back by the street, or this one right here,” Kathy Rossman said.
“And you want to do one of the smaller ones, too, right?” Oakley asked. “Just to get a sense?”
Eventually they settled on four post oaks. The big one by the road ended up being 105 years old. A scrawny tree just 6 inches wide ended up being 50-60 years old. Another was hollow, but Oakley estimated it to be around 140 based on the rings that were there. The homeowners’ favorite — a particularly gnarled one with a low-hanging branch — clocked in around 150.
“Isn't that amazing?” Oakley said. “Nobody would look at that and say, ‘That tree is 150 years old.’”
Oakley and her family-turned-research-assistants are taking these core samples from trees on private property in the Cross Timbers ecoregion. It’s a mix of forests and tallgrass prairie that stretches across Central and Eastern Oklahoma into parts of Kansas, Texas and a teeny bit of Arkansas.
Oakley doesn’t survey trees for a living. She’s a vegetable farmer in Northeastern Oklahoma. But she’s turned her attention from her veggies to the forests that surround them.
“Learning the trees in my area was one of those things that became kind of like a hobby and a place of joy for me,” she said. “So I realized how long I'd been living on just my farm alone and didn't, you know, all the trees that were there.”
Oakley was astonished to learn that for the most part, Oklahoma’s old-growth forests aren’t on protected land — most of them are on private property. That makes them very different from more famous old-growth examples like the Redwood Forests of California.
She thinks many Oklahomans might not realize they have ancient trees in their yards.
“That seemed like this super uplifting opportunity to just reach out to landowners and say, ‘Hey, you know, you might have ancient trees on your land, and would you like us to come and kind of check it out for you? See what you've got?’” Oakley said.
To make that happen, she teamed up with Dave Stahle, a researcher at the University of Arkansas. He uses ancient trees as a historical record — their rings can tell us about temperatures and rainfall patterns from before people were systematically recording them. They give researchers like Stahle a baseline against which to measure climate change.
“We want as pristine a record as we can obtain from these old-growth forests,” Stahle said. “That's why the Cross Timbers are interesting to us, because they preserve tracts of never-logged forest.”
But Stahle says the Cross Timbers are shrinking — for every one acre of old-growth forest in Oklahoma today, there used to be about 17 more.
“But that's still a lot more than other forest types elsewhere in the eastern United States,” he said.
Unlike those forests, the post oaks, blackjacks and redcedars of the Cross Timbers haven’t really been commercially logged for timber. That’s because they’re what a reporter might call “scraggly,” during an interview with Stahle. He disagrees with that characterization.
“They are amongst the most beautiful plants on Earth, give me a break,” he said. “We think old trees are not ‘scraggly’ at all. We think they're gnarly and beautiful, and they bespeak their venerable age.”
But even once they reach a venerable age, the trees of the Cross Timbers aren’t always huge, like that 50-year-old post oak Oakley surveyed.
“It's just a slow growing species,” she said. “That's part of why the Cross Timbers got left in some respects, because, you know, these trees weren't considered valuable enough.”
They got left behind by commercial loggers, but they’ve also missed out on some of the conservation efforts seen in other ancient forests. Stahle reckons about 95% of the Cross Timbers are on private land. That makes them harder to study than ancient trees in a National Forest or other protected area.
“It's kind of hard to go to these last remaining places,” Stahle said.
He and Oakley got a one-year grant from the Kirkpatrick Foundation to offer tree-coring to landowners. The idea is to help them make data-informed land management decisions, but Stahle also hopes it ignites a passion for the trees.
“Can't somebody please care about these woodlands?” he said. “And so that's what we're trying to do. We're trying to raise landowner awareness about the unique nature of some of their forests.”
That grant project is winding down, but Stahle said people who want to learn more about the trees on their land can talk to the experts at the Keystone Ancient Forestor the Nature Conservancy. He also said they can reach out to him — he can tell a lot about a tree just from pictures.
