Seeds of change
Post-fire restoration can affect Western rangelands for centuries
In early July, a bolt of lightning struck the high desert outside of Milford, Utah, lighting a fire that torched more than 300,000 acres of sagebrush and juniper. As residents fled the nearby town of Cove Fort, smoke blanketed Interstate 15, causing a pileup and one fatal crash. It took more than 300 firefighters, two air tankers, two helicopters, 30 fire engines, and nine bulldozers to control the flames of the Milford Flat blaze. A thick blanket of invasive cheatgrass burned like gasoline because, unlike native grasses, it had completely dried out weeks before, dropping its seeds to the soil below.
Wildfires burned nearly 5 million acres in the West this year, much of that in the sagebrush ecosystem where cheatgrass thrives. Though the fight to subdue those fires is winding down, a new, high-stakes drama is just beginning. Government scientists are already in the field, writing restoration plans for the burned areas and taking advantage of a slim window of opportunity to tackle what is generally accepted as one of the great environmental catastrophes of the West: the vicious cycle of cheatgrass and fire.
Before pioneer settlement, sagebrush may have burned once every few hundred years or more, taking more than a century to fully recover. Then huge herds of cattle were turned out onto the land, grazing it down to almost nothing and making way for cheatgrass to invade. Once cheatgrass gets a foothold, an area can burn every six or seven years, which is too much for the native ecosystem to handle. It's up to researchers and land managers to try to break that cycle.
On a heavily grazed private ranch just outside Tintic, Utah, cheatgrass dominates. Just across the road, land that has not been intensively grazed supports a healthier, native community. Steve Monsen, a retired U.S. Forest Service ecologist, says this community - a cheatgrass- and fire-resistant collection of bunchgrasses and sagebrush - is what managers should be trying to re-create after the landscape burns. But that's easier said than done. The science of restoring sagebrush steppe after fires is fraught with trial and error, and each year's restoration plans are part of an uncontrolled, long-term experiment.
The hottest fires consume all the organic material on the surface of the ground, leaving behind bare mineral soil baked into a water-resistant sheet. When the first summer downpours hit, water pools up on this sheet, then rushes along until it gains enough force to rip a fissure into the earth, which grows into a channel that carries away soil and nutrients with every storm.
A summer's worth of monsoons can wreck the soil, and the effects can spread to lakes and rivers, too. After the 1996 Buffalo Creek Fire, the Strontia Springs Reservoir near Denver lost a third of its capacity to sediment buildup, says Lee MacDonald, a professor of hydrology at Colorado State University. So land managers must act quickly after a fire. Once, they would have immediately seeded the area, but recent research has found that seeding is effective at curbing erosion only about a third of the time. The most effective way to stop erosion, MacDonald says, is to cover the soil right away with mulch, such as straw.
Even if erosion is controlled, just beneath the soil, thousands of biological weapons - cheatgrass seeds - are preparing to unleash their destructive power. Healthy sagebrush communities, Monsen says, repel cheatgrass invasion: Sagebrush roots take every available drop of water and prevent weed seeds from germinating. But fire leaves a power vacuum, just waiting for competing factions of weeds to start fighting for dominance. Alongside cheatgrass is squarrose knapweed, which swarms to burned areas in the sagebrush ecosystem. And, unlike cheatgrass, whose combustible straw degrades by late summer, knapweed dries into tinder that sticks around through the winter, raising the specter of a practically year-round fire season.
After a fire, land managers really have no choice but to let buried cheatgrass seeds sprout; there's no practical way to kill them in the ground. But as soon as the green cheat shoots pop up, land managers hit them with a barrage of artillery, much of it controversial. Plateau, an herbicide that targets annual grasses like cheat, is an effective weapon, but blanketing public lands with chemicals ruffles environmentalists. Plowing uproots the cheat, but it tears up everything else, too, and can't be done in rugged terrain. The so-called "Black Fingers of Death," a fungus that kills cheatgrass seeds, provides a promising, less destructive method of control, but still needs to be proven on a large scale.
Once the initial weed insurgency has been put down, biologists have to rally nature's own troops - plants that can compete with cheatgrass - to hold the territory for the long term. They use drill seeders, which cut lean furrows through the cheat barrier, to plant small areas.
But an air assault is required for the big burns. This year, land managers will drop nearly 1 million tons of seeds, most via plane or helicopter, on Utah's burned areas. Then they will bring in the chains with links weighing 90 pounds apiece, with pieces of railroad track welded to some of them for added destructive power. The chains, dragged between two bulldozers, churn up the soil and bury the seeds, which helps them germinate.
Though this ground-pulverizing process may sound extreme, it seems to work. In 1996, the Paul Bunyan Woodpile fire near Fillmore, Utah, burned 100,000 acres of healthy sagebrush and pinon-juniper. The BLM moved in after the fire to shore up the scorched earth, reseed the entire area and then bring in the chains. The Paiute Tribe, however, thought the BLM hadn't done enough to prevent the chaining from damaging cultural sites; the tribe sued, and stopped the dozers and chains in their tracks.
Eleven years later, neighboring parcels at the burn show starkly different faces. In the chained area, scattered clumps of introduced crested wheatgrass dot the ground amid native bluebunch wheatgrass and sagebrush bushes. Nearby, in the places the dozers never reached, a hazy golden carpet of cheatgrass and tumble mustard stretches unbroken for acres, waiting impatiently to burn again.
In a warehouse in Ephraim, Utah, next to piles of native globe mallow plants spread out on tarps, a burly man named Covey Jones feeds garbage cans full of dried wild lupine plants into a combine to separate the seeds. The lupine seeds will soon join the 225 tons of other seeds stored in the warehouse, from small stacks of rare, expensive natives to hundreds of bags of crested wheatgrass, sagebrush and forage kochia.
The facility is run by the Utah Division of Wildlife Resources, and is just one piece of a regionwide effort to supply fire-restoration efforts with more and better seeds. Without this work, all the post-fire erosion control, herbicides and chaining would be for naught.
The work's not easy, though, and, like other restoration efforts, it can be a gamble. For decades, rangeland managers preferred to seed burned areas with crested wheatgrass - it's cheap, competitive with cheatgrass, and ranchers like it for the good forage it provides. But it's an exotic and on its own doesn't do much to help bring back the native ecosystem. Bill Baker, who teaches fire ecology at the University of Wyoming, says that on the Uncompahgre Plateau in western Colorado, land managers are now struggling to remove crested wheatgrass planted as forage decades ago.
Crested wheatgrass, though, won't be abandoned - it's prohibitively expensive to replant thousands of acres using only native grasses. But researchers are trying to change that. At a research station in Fountain Green, a half dozen men work among plots of wild grasses. They use a ShopVac to suck seeds from rows of native buckwheat as part of an effort to efficiently propagate native bunchgrasses and forbs, making it cheaper to add them to the seed mixes. This may not be exciting research, but it's necessary: Until the agencies start seeding with more types of native plants, the ecosystems will remain out of whack, Monsen says.
Jason Vernon, who runs the Ephraim warehouse and is charged with making post-fire restoration efforts more wildlife-friendly, agrees. And this year, thanks to the state Division of Wildlife's help, natives will make up about 30 percent of the seeds scattered over burned public lands in Utah.
Researchers are also developing creative ways to use non-natives. Forage kochia, a Eurasian plant that's competitive with cheatgrass, is turning out to be an unexpectedly powerful defense against cheatgrass - and fire. The Milford Flat Fire stopped short when it hit an experimental plot planted with this exotic species. Though it's not a substitute for native habitat, it's less invasive than crested wheatgrass and nutritious for both wild and domestic grazing animals. Mike Pellant, a BLM ecologist who oversees restoration efforts throughout the Great Basin, says the best way to use forage kochia is not in the mixes that blanket the burns, but as a strategic buffer and firebreak between cheatgrass-infested areas and healthy ecosystems - a method known as "green-stripping."
The first round of seeds - grasses and forbs - will be dropped on Utah's burned areas in October. Then, after the first snow, the planes will fly again, dropping tiny, delicate seeds of sagebrush and forage kochia, which will germinate on the surface of the disturbed ground.
Weeds like cheatgrass and squarrose knapweed are formidable foes - even a century ago, some thought the battle against them had already been lost. But after every fire, people like Steve Monsen and Jason Vernon are ready to fight, because just as the heavy grazing of 150 years ago helped determine what is happening to the land today, today's restoration efforts will decide the fate of Utah's sagebrush ecosystem a century from now.
The author recently completed her internship at HCN and is a freelance writer based in Vancouver, British Columbia.