Dwayne Estes pulls over to the side of a rural road in Franklin County, Tennessee, about 20 miles from the Alabama border. He hops out of his truck and points out a small plant with dainty, trumpet-shaped white flowers with purple-streaked throats. “This is Penstemon kralii,” says Estes, a 40-year-old, 6-foot-3-inch-tall professor sporting a baseball cap and beard, the twin badges of honor for many field botanists. The plant is found almost exclusively at the base of the Cumberland Plateau escarpment, where it survives precariously in narrow, grassy roadside fringes with other rare and threatened species, including a sunflower and a blue-eyed grass yet to be named and described by scientists.
We continue to the top of the steep, densely forested escarpment. Below, a checkerboard of croplands and pastures stretches as far as the eye can see. “Before 1840, those agricultural fields were prairies covering half a million, maybe 750,000 acres,” Estes says. “They were maintained by frequent fires and bison.” The wildfires probably swept up the base of the adjacent escarpment, he adds, keeping it open and sunny oak savanna where the penstemon and its companions could thrive. Like so many southern grassland denizens, they are vestiges of a lost botanical world that once covered as many as 120 million acres from Maryland to East Texas, caught in a vise between habitat loss to agriculture and urban sprawl on the one hand, and encroaching fire-suppressed forest on the other.
The Southeast is one of North America’s great, but forgotten, grassland regions. Its native prairies and savannas have been reduced by more than 90 percent since the first Europeans arrived, almost 100 percent in many areas. Yet the remaining scraps include more grassland plants and animals than the Great Plains and Midwest combined — a big part of the reason why the Southeast coastal plain, the flat, low-lying portion of the region that extends inland from the Gulf of Mexico and Atlantic Ocean, was designated the latest of the world’s 36 biodiversity hotspots in 2015.
The project is resurrecting lost grasslands, opening up the canopy of fire-starved savannas and recreating prairies.
“We’re only now realizing how extensive our grasslands used to be. The losses have been truly staggering,” Estes says.
Known as the “prairie preacher,” Estes is executive director of the Southeastern Grasslands Initiative (SGI), headquartered at Austin Peay State University in Clarksville, Tennessee, which was launched last year to bring back the region’s imperiled grassland habitats through science-based regional partnerships and community engagement. To drum up support for the ambitious effort, Estes has crisscrossed the region some 80 times in the past two years, propelled, he jokes, by Mountain Dew and gas station food. “We’re on a mission,” he says.
SGI and its partners are racing to find plants and grassland remnants in danger of imminent extinction. Many remnants cling to existence along fencerows and roadsides, in powerline corridors and in the far corners of old fields. Because these scant remains are barely enough to even imagine what some grasslands once looked like, SGI and its expanding network of collaborators are also engaged in ecological detective work, piecing together tips such as the presence of isolated survivors like Kral’s penstemon, as well as clues in 200-year-old land surveys and other historical artifacts. With this evidence and a growing army of volunteers, they are resurrecting lost grasslands, opening up the canopy of fire-starved savannas and recreating extirpated prairies from scratch on former agricultural fields.
In a world full of shattered grasslands — grassland is the largest and most threatened of the planet’s four major terrestrial biomes, as well as the largest in North America — SGI is “charting a new course for conservation in the 21st century,” Estes says.
According to the old saw, when the first Europeans arrived in North America, they encountered a forest so thick that a squirrel could travel from the Atlantic to the Mississippi River without ever touching the ground. The 2012 publication of Forgotten Grasslands of the South, a book by pioneering conservation biologist Reed Noss, drove a stake through the heart of this time-worn narrative. “I had become familiar with many of these grasslands since the early 1970s, but was surprised and saddened by how few people knew about them and appreciated them,” says Noss. “I guess I felt compelled to speak up for the underdog, especially after learning how amazingly rich in biodiversity these grasslands are, and how imperiled many of the species are.”
Noss’s book demolished another myth as well — that grassland regions are found where there is too much rain for desert but not enough for forest, as in the Great Plains and Midwest. According to Noss, whether or not a particular landscape in the rainy Southeast supported grassland depended on factors other than precipitation to keep the forest at bay, especially fire. Wildfires sparked by lightening, he points out, are more frequent in the Southeast than any other part of the country. For millennia, the trampling, rooting, and wallowing of large herbivores like bison also discouraged the growth of woody vegetation. In some areas, droughty shallow soils, or soils so high in minerals that they are toxic for most plants, support so-called “edaphic” grasslands such as limestone glades and serpentine barrens.
In fact, the Southeast supports more types of grasslands than its mid-continental counterparts. Historically, savannas dotted with oak and pine were the most widespread, occupying more than 100 million acres. The savannas were carpeted by a rich diversity of sun-loving wildflowers and grasses. But this unique ground flora has disappeared as fires have been suppressed, shade-tolerant trees have colonized the areas, and their canopies have closed. Prairies once covered an estimated 7 to 10 million acres across the Southeast. Not surprisingly, these largely treeless landscapes were the first to be converted to farm fields and range lands. Rocky glades and barrens, mountaintop grasslands called balds, coastal grasslands, and a variety of wet grasslands such as marshes, streamside meadows, riverscours, fens, and bogs were less extensive but often supported rare and unique plant communities. While some Southeastern grasslands resembled those of the Great Plains and Midwest, most were smaller and embedded in a matrix of woodlands and forests.
Although naturalists have explored the Southeast for centuries, species new to science are discovered in the region every year. According to Alan Weakley, director of the University of North Carolina herbarium and SGI’s chief botanist, right now researchers know of more than 100 as-yet-unnamed plant species new to science, more than three quarters of which are found in grasslands. Many are narrow endemics like Kral’s penstemon, which grow in a small area and nowhere else in the world.
What’s more, at a fine scale (less than 100 square meters), Southeastern grasslands have some of the highest plant richness in the world. A prime example is North Carolina’s Green Swamp Preserve, home to rare species of conservation concern, like the Venus flytrap and the Grasshopper Sparrow. According to Johnny Randall, director of conservation programs at the North Carolina Botanical Garden, a regional partner of SGI, as many as 50 plant species have been found in some one-square-meter plots of the preserve’s wet pine savanna. At the 10-square-meter scale, Randall says, “it’s upwards of 80 plant species.”
These native plants and their associates “can come back if you give them what they need – sunlight and fire,” says a scientist.
As Southeastern grasslands have disappeared, so have their iconic fauna. Bison were extirpated more than two centuries ago. The Northern bobwhite and Eastern meadowlark, both native birds, have both declined by 75 percent or more during the past 40 years, and the remaining populations are expected to shrink by half in the next 10 to 25 years. The number of monarch butterflies has dwindled along with the grasslands once studded with wildflowers that fueled the insect’s reproduction and epic migrations to and from the mountains of central Mexico.
Since the 1980s, however, most conservation activity has generally focused on the preservation of large tracts of forest and mountainous land and the protection of native biodiversity on so-called “working landscapes” such as active farms and cattle ranches. “It’s hard to convince conservationists to buy a few hundred acres of degraded land because it has some remnant savanna species on it,” Estes says.
But recent research suggests that such small, local patches of habitat are crucial to the survival of many rare and endangered species. They are also a critical source of seed for restoration efforts. A global study published in Proceedings of the National Academy of Sciences in December looked at the conservation values of vegetation patches in 27 countries on four continents. “We should rethink the way we prioritize conservation to recognize the critical role that small, isolated patches play in conserving the world’s biodiversity,” the authors concluded. “Restoring and reconnecting small isolated vegetation patches should be an immediate conservation priority.”
As Estes puts it, “The paradigm of the past 25 years isn’t working. We need a new approach.”
Often, this new approach requires figuring out where lost grasslands once grew. In the words of Theo Witsell, chief ecologist and co-founder of SGI, “in many areas this is almost a forensic exercise because the grasslands are so long gone.” Although many disappeared before they could be described and studied by naturalists, he says, they have left behind clues.
“It would be difficult to imagine anything more beautiful,” Tennessee settler Reuben Ross wrote in 1812 of the once vast Pennyroyal Plain Prairie of southern Kentucky and northern Tennessee. “Far as the eye could reach, they seemed one vast deep-green meadow, adorned with countless numbers of bright flowers springing up in all directions.”
The accounts of early explorers and settlers are full of such descriptions of now-defunct grasslands. Old maps and land surveys help pinpoint former grasslands as well. A French map of the Southeast from 1720, for example, depicts extensive areas of “savanna” and “good pasture ground.” Old place names like Barren Plain and Prairie Grove also hint at an area’s grassland heritage. In Witsell’s words, “there are more Prairie Creeks across the Southeast than you can shake a clump of big bluestem at.”
But the biggest giveaways are grassland plants themselves. Species called “conservative heliophytes” by scientists are found only in grasslands. If you encounter American chaffseed (Schwalbea americana), a perennial wildflower with an upright growth habitat and showy reddish purple flowers in spring or early summer, for example, “it’s safe to say that you are standing in a grassland remnant,” Witsell says. The species has been on the federal list of endangered and threatened species since 1992. But the best part of finding a conservative grassland plant, he adds, is that it’s a sign that the site is “recoverable.” These plants and their associates “can come back if you give them what they need — sunlight and fire,” he says.
Many original grassland plants are preserved in old herbarium collections. In recent years, these dried specimens have been digitally scanned and made available online, providing researchers with a wealth of data on where grasslands were located. The label on each specimen includes not only the plant’s scientific name and the date it was collected but also the location where it was growing.
In a project Estes calls “recliner botany,” SGI has employed citizen scientists working from the comfort of their own homes as far away as Melbourne, Australia, to input the label information from thousands of herbarium specimens using an application called Notes from Nature. Once this information is georeferenced, or assigned latitude and longitude coordinates based on the location listed on their labels, it can be used to map the presence of historical grasslands.
“It piques my curiosity about where I’m from,” says a field volunteer on the Southern grassland project. “This is my classroom.”
In addition, giant trees scattered throughout the region are testaments to once flourishing savannas. Estes calls them “storyteller species.” At an overgrown pasture a few miles east of downtown Nashville, part of a peninsula formed by a large bend in the Stones River that is being transformed into Ravenwood Park, he points out enormous chinquapin oaks. “They are 300 years old, maybe four or 500,” he speculates. At the top of a nearby knob, Estes nods at a massive bur oak with impressive spreading limbs. “This tree would have been here when the bison were here,” he says. “Nobody in Nashville knows the story of these trees and what they could tell us if they had a voice.”
About a dozen volunteers fan out across the former pasture to do a “bioblitz,” using an application called i-Naturalist on their smartphones to document other traces of the extirpated plant community that might be hidden in the surrounding sea of Japanese brome grass, tall fescue, and other non-native grasses. The area is a former Native American hunting ground once called Clover Bottom, and Estes is keen to find a species called running buffalo clover (Trifolium stoloniferum), last observed there in 1780. The plant apparently followed in the wake of large herds of bison, which periodically disturbed the landscape, creating its preferred habitat. In 1987, it was put on the federal endangered species list. A large portion of Ravenwood Park will be restored as savanna, ideally with the clover and a small herd of bison.
“This is what I was meant to do,” says Sue Bible, one of the Ravenwood volunteers. “It piques my curiosity about where I’m from. This is my classroom.” SGI plans to work with its regional partners to build teams of volunteers like Bible in dozens of towns and cities who can assist with restoration in the field while spreading the word about native grasslands in their communities. Because so many grassland remnants are small, they are ideal for engaging the support of volunteers at the local level.
Restoring the Southeast’s imperiled grasslands, says Estes, will require an undertaking on a scale “unprecedented in the history of American conservation.” To meet this challenge, SGI is seeking major funding from philanthropic, corporate, and government sources. Google is funding the recreation of a 45-acre prairie at the main entrance to its data center in Clarksville, part of the lost Pennyroyal Plain Prairie. SGI, in collaboration with the Tennessee Plant Conservation Alliance and the Tennessee Department of Transportation, has also embarked on a project called “Rubbernecking for Grasslands” to document remnants along more than 4,000 miles of the state’s highways.
With so much of the Southeast’s grasslands already sliced up by roads, plowed up, grazed over, overgrown by forests, and fragmented by sprawling cities, there is no time to lose. “If we wait 25 more years,” says Estes, “it will be too late.”