woody encroachment – Across the Great Plains, a quiet environmental shift is unfolding as invasive trees overtake native grasslands, threatening biodiversity, water supplies, and the ranching economy.
From the cockpit of a Bonanza A36 plane, the Nebraska Sandhills look like a vast, undulating sea of grass. To Shelly Kelly. a rancher who grew up hunting for mudpuppies in buffalo wallows and weaving bouquets of flowering grasses. this 19. 500-square-mile expanse is home. But from the air, she can see the shadow of a slow-motion crisis: the eastern red cedar.
Down on the range. these trees—once planted by settlers as windbreaks to protect calving heifers—are escaping their orderly rows. They scatter across the hills like runners breaking from a pack, a phenomenon ecologists call woody encroachment. Some refer to it as the “green glacier,” a steady, silent crawl that is fundamentally altering the American prairie.
For ranchers, the stakes are immediate. Texas A&M Agrilife extension estimates that woody encroachment across the 10 Great Plains states has resulted in $4 billion in lost range production. When trees take over, the grass disappears, and with it, the livelihoods of those who rely on the land. Beyond the economic hit, there is a looming ecological cost. Experts warn that biodiversity—the insects. birds. and small mammals native to these ecosystems—is in decline. while thirsty trees place a heavy burden on water supplies in increasingly arid regions.
This encroachment is fueled by a complex mix of culture and biology. For generations. Nebraska promoted itself as the “Tree Planter State. ” a legacy rooted in the 1862 Homestead Act and the 1904 Kinkaid Act. both of which encouraged settlers to plant trees to secure land titles. Today, those well-intentioned traditions have turned invasive. Without fire to keep them in check. the junipers develop thick bark. grow rapidly. and seed across 200-foot radii once they hit five feet in height.
Fire, historically the prairie’s natural immune system, has been suppressed for too long. While some regions. like the Flint Hills of Kansas and Oklahoma’s Osage Hills. maintain a culture of prescribed burning—dating back to 1915 lease contracts that mandated fire to ensure cattle grazed on tender. nutrient-rich regrowth—many other areas have lost that practice.
Changing the tide requires a shift in how we view carbon. While planting trees is often held up as a virtuous climate solution, grasslands serve as a more secure carbon sink. Unlike forests. which store carbon in vulnerable trunks and leaves—making them susceptible to massive release during wildfires—prairies sequester carbon safely underground in deep root systems. As the planet warms. atmospheric carbon may actually be giving woody plants a photosynthesis edge. potentially accelerating the displacement of the grass that has defined the Plains for millennia.
There is no “hands-off” solution here. As Chris Helzer. Nebraska director of science and stewardship for The Nature Conservancy. notes. the prairie has always evolved alongside human intervention. Groups like the Sandhills Task Force, which Kelly leads, are now working to turn the tide. They help ranchers secure funding to cover up to 75 percent of the costs for cedar removal. aiming to preserve the 4 percent of tallgrass prairie that remains—the most altered landscape in North America.
On the ground, the work is manual and persistent. John Taylor, Kelly’s father, has kept the cedars off his own land, though he can still see them creeping in from the fenceline of a neighbor’s property. The trees are prolific, but they are vulnerable; cut a red cedar to the root, and it stays dead.
For those who know the subtle power of the plains, the mission is clear. It is not about eradicating every tree. but about recognizing the line between a healthy. functioning grassland and a landscape lost to a encroaching woodland. With the right mix of grazing. burning. and restoration. those who live on the Plains believe there is still time to keep the prairie open. vibrant. and alive.
Nebraska Sandhills Great Plains woody encroachment eastern red cedar prairie conservation ranching grassland biodiversity