High Country News investigated rangeland science in southern Colorado and New Mexico, digging through the scientific literature and interviewing dozens of ranchers and range scientists. The search unearthed plenty of anecdotal accounts, but only three examples of hard data, gathered independently of the ranching industry, to back up the claim at the heart of Quivira’s philosophy: that extended use of "rest-rotation" grazing results in ecological recovery.
The most rigorous study covered two years of grazing on the Gray Ranch in southwest New Mexico’s Hidalgo County. There, researchers fenced a relatively uniform 8,803-acre pasture into four smaller plots. They rotated the cattle through each of them in 2000 and 2001, and, in 2002, they rested the land for a year.
The study was led by Charles Curtin, who runs a nonprofit research institution called the Arid Lands Project and is scientific adviser to the Malpai Borderlands Group, an organization of ranchers, government regulators, conservationists and scientists who jointly manage 800,000 acres in southeast Arizona and southwest New Mexico.
The results: When cattle were present, the vegetation was significantly thinner than on the ungrazed plots. After the area was rested, however, vegetation rebounded, and actually surpassed the ungrazed plots in terms of species richness. Likewise, small mammals fared better on grazed than ungrazed plots in 2002.
Curtin admitted that two years of study aren’t enough to draw firm conclusions. Still, he wrote, the results demonstrate that grazing there — even during a drought — had a positive effect on density and diversity of plants and animals.
Another study, carried out over a much longer time frame, comes from the Forest Service in western Colorado. The Paonia Ranger District says that decades of "before and after" photos show that a combination of lower cattle numbers and a switch from season-long to rotational grazing produced thicker grass cover and less bare ground on five allotments.
The rotational grazing works because it causes cattle to graze areas they would not normally graze, says Forest Service Range Supervisor Dave Bradford, and because it reduces the total time plants are exposed to cattle. "This allows plants to grow before grazing, or re-grow following grazing," he says.
A third study by the Bureau of Land Management in 2003 looked at rancher Jack Hagelstein’s Comanche Hill allotment on BLM land near Roswell, N.M., and concluded that the site met the bureau’s rangeland health standards for 22 different indicators of soil stability, biotic integrity and hydrologic functions.
The skepticsMany researchers, however, remain skeptical that rotational grazing makes much difference.
Jerry Holechek, a New Mexico State University range science professor, has long been a heretic in the grazing world. His published reviews have repeatedly concluded that the number of cattle on a ranch plays a far bigger role in determining the land’s health than whether the cattle graze year-round or rotate through.
A more surprising dose of skepticism comes from Joel Brown, a rangeland scientist with the federal Natural Resources Conservation Service in Las Cruces. Brown grew up on a ranch and was once president of the New Mexico chapter of the Society for Range Management; he views his job as helping ranchers, and professes great admiration for the Quivira Coalition.
But Brown doubts that a rancher can increase the productivity of plants or soil by changing the timing or intensity of grazing seasons.
"You can use grazing systems to shift species composition, build up forage reserves, increase fine fuel for a planned burn or favor rare species. I have even designed grazing systems to help increase California condor habitat," he says. "But I know of no objective evaluation or studies that demonstrate increased productivity by livestock rotation."
Tom Fleischner, a Prescott College ecologist and longtime grazing critic, points out that ranchers tend to be most interested in forage — "Read, ‘grass’ " — while ecologists tend to look at native biological diversity. "That’s why everyone might be looking at the same stuff and reaching different conclusions," he says. "The grass might be going up, but songbirds may be going down."
Scientifically, the verdict is still out, agrees Nathan Sayre, an assistant geography professor at the University of California at Berkeley who wrote The New Ranch Handbook for Quivira in 2001. The handbook says that ranching can be sustainable because rangeland systems can tolerate and recover from grazing if the disturbance isn’t too great. But Sayre said his review of the scientific literature found that rotational grazing studies have been far from conclusive.
Still, Sayre insists that many rotational grazing programs are better than earlier systems because they are more flexible. "The key is monitoring and responding to changing circumstances," he says.
Wanted: good dataRange professionals who work with ranchers are the first to acknowledge that the monitoring is not what it should be. Charlie Orchard, a range consultant in Wyoming, has tried to remedy that by developing an elaborate range-monitoring system that measures about two dozen indicators of four ecological power points: nutrients, water, plants and energy. The monitoring shows how well the overall ecological system functions.
Orchard compares monitoring a ranch to checking your car for oil. The problem is that ranchers’ dipsticks don’t have an obvious line or clear messages that say "If it decreases below this line, lower (livestock) numbers. If it goes above the line, raise numbers."
Monitoring isn’t cheap: Orchard’s system costs $1,400 to $2,000 per monitoring site each year. If a rancher uses a consultant to look at five sites on his operation, that can run up a $10,000 bill.
Orchard has taken 700 ranchers in 13 states through his classes over the years, but he believes that at most, 10 percent are actually doing monitoring today.
Kirk Gadzia, a Bernalillo, N.M., consultant who works with many Quivira ranchers, agrees that monitoring needs to ramp up. Most of the ranchers he works with aren’t trying to prove anything, he says: They’re just doing the best they can to make a living. "I struggle pretty hard to get them to get photo points (where ranchers take repeated photographs over time, to document changes)."
Quivira’s director, Courtney White, doesn’t deny that uncertainties exist, but he believes strongly that the coalition’s grazing methods work. "I’ve heard so much anecdotal evidence in so many different landscapes," he says. "There clearly is some pattern at work there.
"We have too many crises to sit and wait for the research community to deliver the final verdict here," White adds. "I have to go with what works on the ground."