Marking time in Duke Forest

The forest works on a different time scale.

Duke Forest, 7,000 acres in six divisions sprawled across Durham, Orange, and Alamance counties, where hardwoods tower and even Highway15-501 becomes a distant rush that actually might be a river, or the wind in the pines. When life speeds up, the forest slows it down.

Consider the Stony Creek, which runs through a culvert beneath the forest trail into the peaceful, little-hiked Edeburn Division of the forest. On a bright fall day, you see other hikers and even a couple of bicyclists in spandex, despite signs proscribing bicycles. Late mosquitoes trouble you as you sit by the creek, listening to cicadas and the pops as falling acorns hit leaves on their way down. A monocular carry helps you identify the laughing bird cry you’ve been hearing as a pileated woodpecker. Bluejay shrieks need no identification. Japanese stilt grass fills the ditches by the road as the creek chatters over rocks downstream. Upstream a dam looks too even to be natural, but a somewhat squishy investigation shows it’s nothing but sticks. Some still have tooth marks from the beavers that put them there. An orange butterfly makes its helter-skelter flight in the silence, and on the still pool by the dam you see water skeeters, both the leggy kind and the buggy kind. Green lichens spread over rocks, and mosses cover a tree stump dappled in sun. You sometimes hear a car go by on Old N.C. 10.

This is the forest, and spending time investigating the forest seems like a sensible response to the moment. Assistant forest director Jenna Schreiber lives in the same world you do, and she says the forest soothes. “One thing that’s brought me a lot of peace and grounding during this crazy time, and something I think about in this position a lot when I start feeling overwhelmed,” she says, “is I try to think about things on a forest time scale.”

A forest time scale. Planning for forest management forces her to think on time scales of decades, even centuries. “On a fifty-year rotation, a fifty-year time scale?” she says of current stresses. “It doesn’t make that big of a difference.” This is comforting. We all profit from thinking on the forest time scale. Even more so when the human time scale seems so frenetic.

But Duke Forest director Sara Childs reminds you the forest has many other jobs beyond soothing frazzled spirits. “It’s not meant to be another Eno River State Park,” she says. The forest has been part of Duke for nearly a century (next year is its ninetieth birthday), and it’s in the middle of a five-year strategic plan that emphasizes the ecological stewardship and research on which the forest has always focused, but intensifies a style of community engagement that includes citizen science. Even in its interaction with the community members who hike and bike there, the forest wants to be a little more like Duke, emphasizing science and learning, engagement and adventure. Seeing “the natural world,” Childs says, “as laboratory. As classroom.”

THE FOREST CAME FIRST.

Of course, that’s obvious in the natural sense: There was land before James Buchanan Duke built a university on it. But in a more intimate sense, when you sit in, say, the Penn Pavilion, you’re in Duke Forest. Not because you can see trees out its broad windows or even because Anderson Woods, behind it, is still forest and still surveyed by professors and students from the Nicholas School, but because the land for West Campus was carved out of the enormous holdings that have become the forest.

When Duke decided to turn Trinity College into a university, job one was acquiring land around the existing college, currently East Campus. Word got out, and prices skyrocketed. There was talk of moving the university to Charlotte.

At which point then-president William Preston Few took a walk west of campus. He likened himself to Keats’s “stout Cortez,” he later wrote, “when I stood on a hill, looked out over this wooded tract, and realized that here at last is the land we have been looking for.” Buying commenced and has not stopped—the forest acquired a new piece of land as recently as 2019. The first major purchases totaled around 8,000 acres, of which 5,000 became the first lands of Duke Forest.

The reason even people as rich as Duke could afford so much land was because, in the words of professor of botany emeritus and founding dean of the Nicholas School Norm Christensen, “it had kind of had the hell beat out of it.” Deforested in the eighteenth and nineteenth centuries, the land of the Piedmont had been farmed virtually to death. Its owners had either abandoned it or were glad to sell it cheaply. That was bad news for the land and the farmers, but good news for Duke and the new professors coming to town. Advised by prominent foresters, Few realized that the land was of enormous value if it could grow trees, Christensen says. “But we don’t know how to grow these trees, and we don’t know anything about the process” by which old fields revert to natural areas. The foresters recommended that the university dedicate the land as a research, teaching, and demonstration forest, and in 1931, on Few’s recommendation, the trustees did that.

“The point I’m making,” Christensen says, “was that old-field succession was an integral part of that dedication.” Old-field succession is the process by which abandoned farmlands progress through stages. First grasses colonize. Next come pines like loblollies, which prosper in harsh sun and bad soil. When the pines get strong enough, they blot out the sun below, which prevents further pines from growing but not the progeny of surrounding hardwoods like oaks, hickories, beeches, and maples. If left alone, the pines will likely collapse after a century or so and the hardwoods will prosper.

This is simplified and overgeneralized, but old-field succession is an understood process now. It’s the story of the entire Piedmont, and the main research into it was done in Duke Forest. Clarence Korstian, the forest’s first director, addressed succession from a pragmatic, traditional forestry perspective: “How do trees grow, how do we manage forest in ways that are sustainable but productive?” Christensen says. Ecologist Henry Oosting, hired in 1932, a year after Korstian, was another towering figure in succession, writing some of its most-cited early papers. “They were very focused on what was an ecological process and frankly couldn’t give a damn about whether you could sell a piece of wood or not,” Christensen says of the differing viewpoints of the two men. “It was a creative tension.” And for nearly a century, Duke Forest has been researching ecological processes and growing wood.

One of the forest’s largest and most-used divisions is named for Korstian, and a natural area, where the forest is left unmanaged for research, is named for Oosting. In 1975, early in his tenure, Christensen found data left by Korstian on eighty-five permanent plots in the forest. “He went in and marked out the corners and mapped and measured each individual tree.” Christensen and a colleague from UNC “went back out to these places and located these trees. They had numbers painted on them.” He excitedly shows off Oosting’s own forest map, which he owns as a keepsake. “He actually glued it to canvas so he could fold it up and carry it out to the field with it. You can see the water stains on the back.”

They began resurveying, a process that has “continued every five to seven years, continues to this day.” Data on tree diameter, foliage, height, and sometimes other characteristics are now available for some spots in the forest for nearly a century. “Then we established another 250 permanent plots. The point is, we have this archive of data that allows us to ask a whole host of questions. And the questions we ask today are not anything like the questions Korstian imagined back in 1931.” The research has never stopped. Korstian wondered about wood volume for harvest; current researchers, from Duke and all over the world, are more interested in things like climate change.

“It’s the historical database accumulated now over a century that has really set this place apart,” Christensen says of the forest. “As an ecological observatory, a place we can really talk about and study long-term change.”

ON A SUNNY LATE FALL DAY, you join the Duke Forest Research Tour. Forest director Sara Childs wears a baseball cap, a bright orange visibility vest over her sweater, and hiking boots as she steps from the white SUV she has piloted to your first stop. About a dozen interested community members are split between two vehicles, and the first stop is in the Durham Division, where professor of earth systems science Ram Oren will talk about the Five-Pines Study. “Let me get something for me to take notes with,” Childs says as she climbs back into the truck. “Because I always learn something on these.” Childs got her master’s in environmental management from the Nicholas School in 2008 and says, “It’s fun to work professionally with some of the professors I had when I was a student. Just to continue learning.”

The group hikes into the forest along a cleared right of way beneath electrical lines, and people make their way to a patch of forest that was evidently cleared a decade or more before. Pines of various species stand about twenty feet tall everywhere you look. Oren stands before the group and tells the story of an engineer he went to for help in understanding needle structure among various pines. The engineer instantly opined that long needles would come in bunches, whereas shorter ones would run along the branch. “And if you look here you see longleaf pine, and if you look there you see shortleaf, and there you see Virginia pine, and he was right on.” Those pines all have long needles, bunched together like the end of a toilet brush.

Oren has designed an experiment that takes five types of pines (the other two are slash and loblolly) and planted them together to watch them grow. He’s taking into account hydraulic properties and things like the angle of the sun and figuring out which pines do better in different circumstances. He talks about trees paying “the construction costs” of needles in different configurations, about the success of loblollies and slash in the ruined soil left behind by agriculture, explaining how the other trees do fine but improve under different conditions.

Two more stops on the tour, one at the campus farm, where graduate students pass tiny potted shoots to the visitors. The shoots are from a Duke Forest spot that is part of a global network of sites growing cloned seeds at various places and under various conditions to see what kind of adaptations emerge. Each little pot with a shoot in it has a tag, showing what genetic strain it is and what conditions it’s getting: Does it get water every day? Sunlight? Changes in phenology— when and how the plant undergoes its various cyclical processes, like budding and leafing—will determine its health.

The final tour stop takes you to the Blackwood Division, almost entirely left to its natural processes and largely closed to the public. As you walk in, you pass a series of laundry baskets on little poles, and graduate student Chase Nunez soon explains: They gather all the seeds dropping from nearby trees. With surveys of what trees stand where, the baskets help them map the forest’s output. “You can think of all these little baskets as detectors of the signal from every single one of these trees,” Nunez says, giving them information on not just seed production and dispersal but also the support of animals that depend on the seeds; on predators that depend on the animals; and on how climate change is affecting the whole ecosystem. The laundry baskets on poles are far from the only clues that you’re in a scientific forest: Trees bear spray-painted markings or metal tags; yellow or red tape flutters from trunk or limb. Everything is involved.

One visitor asks whether the number of downed trees seems excessive. Good eye: “We do have a hurricane gap simulation going on,” Childs says. Forest workers pulled down trees in 2002 and 2009 to simulate hurricane damage. “We’re starting to see the regrowth pattern.”

WATCHING ALL THAT science draws you to a citizen science project organized by the forest.

You attend a midwinter meeting in the Nicholas School, eating donuts and drinking coffee with forty or so volunteers, and you learn about an app and a project website. Your job will be to monitor that phenology you heard about on the tour: When buds come out, when leaves unfurl. You’ll sign up for a specific spot in the forest—a transect; basically a section of trail—and specific time periods, and you’ll observe. Childs and some scientists have tagged certain trees, and you will find them and answer questions about whether you see buds or not, whether buds have opened into leaves. The forest is one of 8,400 sites in this project; there are 8.2 million records so far. You will be adding to information pools that stretch back to observers like Thoreau, whose notebooks tell us when buds were coming out in New England in the 1850s.

THIS LEADS TO A SERIES of midwinter walks in the forest, a landscape of gray and brown: gray tree trunks, brown leaf litter, and brown boughs high up in the canopy, where you train your little monocular to see whether there are buds. You walk through the quiet forest, hearing only bluejay calls and the crunch of your shoes. You stop at each of your sites; every time you find the specific trees, marked by blue tape and a metal tab identifying its species (ACRU, for example; for Acer rubrum, red maple), you feel like stout Cortez, or anyway like William Preston Few. At the innermost spot, on a rocky outcrop overlooking the New Hope Creek, a gaze through the lens at the uppermost boughs shows that yes, indeed, the buds are out, tiny red nubs at the end of twigs you can just see if you squint, and you feel like you’ve seen a tree bud for the first time in your life.

On another walk you look down and notice a tiny purple wildflower. Another walker stops, too, and consulting various apps and books, you and she agree that it’s probably hepatica, one of the earliest bloomers. There’s no place to mark its bloom on the phenology app, but other wildflower social-media apps will give her a chance to claim it as her own observation, and she wants no competition. She makes you promise that if you share an image of it yourself, “you can say it’s Duke Forest, but don’t say which gate!” (It’s been a while ago, now. It was Gate 26.)

GATE 26 IS ONE of the forest’s most-used gates, halfway between downtown Durham and Chapel Hill, and rare is the time you can park by the side of the road and be the only car. On a chilly spring morning that feels like it might be the year’s last hoodie weather, you stand a quarter mile up the forest road from Gate 26. You’re with a couple of dozen community members who have signed up to join a spring flora and fauna tour, led by Nicolette Cagle, a lecturer in the Nicholas School. “Today,” she says, “I want us to think about our senses.” She reminds you of the Japanese concept of shinrin-roku, “forest bathing”—the feeling of well-being you find in the forest—but quickly reminds you that you should learn something, too. She notes the song of a red-eyed vireo, then starts down the trail, surrounded by happy forest bathers.

Everything she sees, she explains. Barely a few steps along she squats to show off Salvia lyrata, a foot-high plant with hanging purple blossoms and a square stem also known as “lyre-leaf sage” or even “cancer weed” for its propensity to spread. It’s edible, and Native Americans used it as a salve. A few steps further on she points out muscadine, the local wild grapevine. “If you take a sharp stick and jab it into a muscadine stem, it will start dripping water,” she says. “Now you know a survival skill.”

It goes on like that for an hour. She captures and has you smell a cyanide millipede (“sorry, little guy—hey, don’t bite me, bud!”). You can boil wood sorrel to get a yellow dye; it sometimes closes its flowers at night like morning glory, a process called “nyctinastic movement.” She decides not to open a gall to see the wasp larvae that cause it, admits that nobody knows whether rattlesnake ferns get their name as habitat or bite treatment, and introduces you to the Virginia pennywort, a mychoheterotrope, which means it shares resources with the trees on which it grows. “This is in some ways a cute, tiny little beautiful parasite,” she says. It somehow helps the trees share resources one to another: “The trees share resources through fungus,” she says. “What we don’t know is the why.”

She is teaching you to truly be in the forest. Here she digs into the earth to show off snails that seem to be constantly under study in the Korstian; there she urges you to close your eyes and just listen. The point, she says, is “deep noticing.”

This reminds you of a description of a walk in the woods with Clarence Korstian himself in 1931. “See here,” the writer describes Korstian examining the soil, “this little salamander, picking his way through the leaves. Here’s the runway of a rodent. That’s a field mouse or a shrew. If we sat down quietly here for a while, on a hot day, the whole place would be alive with sounds of the animal life—the spiders, the worms, the bugs, the rodents.

“Most people do not understand just what this life means not only to the trees of the forest but also in rebuilding the soil for further use as farming land. It must be protected by all means.”

WALKING DEEP INTO the forest, you hear a rumbling, and as you turn a corner you see an open area, recently clear-cut. Tall pines stand along the edge of the field, which is otherwise covered by boughs, needles, and other pine litter. By the road, forest supervisor Tom Craven is driving a loader, smoothing out some dirt in the deck. “The deck is where they load the wood,” he says—a process you can see has already taken place here. He’s preparing it for the next time an adjacent parcel will be harvested. Underneath the machinery, soil compacts, so you want to keep the deck as small and stationary as possible, though they throw down seeds for natural grasses and wildflowers to help things along. He’s thinking about the future. But he’s harvesting pines because of the past.

This was old farmland: “I could tell as I walked the forest. You could see the old furrows,” and as Christensen told you, nothing grows better on farmed-out land than loblollies. This was its first harvest since it was purchased. A nearby silviculture sign—a post in the ground, with horizontal slats for each event in the forest’s life—tells the story of another parcel: Loblolly pine/planted 1932/ thinned 1954 & ’64/seed tree harvest 1988/natural regeneration 1989/pine release 1990/seed trees removed 1992/ precommercially thinned 1996/thinning 2013.

That’s like reading the family Bible for this patch of forest. Seed tree harvest means the plot was clear-cut, with a half-dozen or so of the best specimens left standing to reseed the field. “Pine release” is the clearing out of competing vegetation, and thinning is just what it sounds like. Almost a hundred years of forest management history in twenty-seven words. These signs stand everywhere in the forest, giving pocket histories of parcels, and Childs sees them as vital.

The forest is managing timber as a natural resource, and she thinks it’s vital that people see what that looks like. In an urban area, “we actually feel quite separated from, and we lack the appreciation of, the entire life cycle of where those raw resources are coming from.” She says the forest gets little pushback from its more rural neighbors, but closer to the cities people sometimes reflexively object to any cutting they see. “We always want to have this opportunity to show that timber management is a part of sustainability, and part of renewable resource use,” Childs says.

Renewable indeed. Duke Forest has never been fertilized; those boughs sprinkled over the field, and the roots left in place, put nitrogen right back into the soil. The harvested timber provides money for the forest’s management. And the forest itself has renewed thousands of acres of land that ninety years ago were all but dead.

FOR A LAST LONG WALK, you head past Gate 22 and along the gravel road called Nettie’s Fire Trail. The road quickly diminishes into a gravel double-track, then after a right at a couple of trees into a leafy double-track alongside a sunny field of broomsedge and Queen Anne’s Lace and other ditchy plants, with tall pines growing along the edge. Tiny ones show up in the middle of the fields.

As you go on, the pines grow taller, soon replaced by oaks and poplars, and the shade grows darker. The road becomes truly a trail, grass and decomposed leaves leading into the dimness. In the silence you can just hear the Pine Mountain Creek, burbling further down the slope. Above your head boughs seem to reach across the trail; occasional blotches of sun filter through, but you are deep in the forest now. And then, through the tall oaks, maples, and sweet gums, you see.

A clapboard house, one story, once painted white, but that was a long time ago. Peaked tin roof, covered in rust and pine straw and leaves. Keep Out and No Trespassing signs warn against entry, but a glance at the house already does that. The windows are empty. Inside, most floors have collapsed, into the puddles of a dark empty cellar. Concrete steps leading nowhere, yards from the doors, betray porches long rotted away. The house is empty, and has been for half a century. The forest has it now.

Like the piedmont itself, it’s being transformed, turning from a house back into the forest originally cleared for its building, just like the land on which it sits. The Nettie of Nettie’s Fire Trail was Nettie Couch, the last person who lived on this land, from whom it was acquired, in 1947, to be one of the last large acquisitions of Duke Forest. That’s a perfect ending for a hike. Duke Forest is a place of transformation.