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Buck Up Science isn't on the rancher's side. By Susan Zakin This is one of those times when I know I haven't sold out. If I had, I'd be furiously digging up dirt about Tom Cruise and Nicole Kidman's divorce. Instead I'm writing about animals even dumber than Scientology-worshipping movie stars. That's right. Cows. Everybody knows that County Administrator Chuck Huckelberry sees the preservation of Pima County ranches as an elegant solution to meeting the requirements of the Endangered Species Act. Just give the good old boys and girls another big, fat subsidy--the $400 million a year that U.S. ranchers get isn't enough--and they won't sell out to developers! We'll have all that great open space! Gee, the owls will be happy and so will the politically powerful ranching community. The trouble is that the science doesn't back up this position. Livestock grazing in the arid West, where average rainfall is below 12 inches a year, causes ecological damage. Some of the damage is already irreversible. If we don't stop soon, more places will be trashed beyond repair. In Arizona, a U.S. Forest Service research study found that livestock grazing is the number one cause of species endangerment. Studies conducted for Pima County as part of the Sonoran Desert Conservation Plan found that livestock grazing has negative impacts on 42 of the 52 species that are supposed to be protected by the plan. Ranchers like to argue that the damage done to the Western range happened back in the frontier days of the 1880s, when a combination of overstocking and disastrous weather conditions caused the deaths of about 30 percent of range cattle in the West. But the research shows that things have only gotten worse. In 1994, the U.S. Bureau of Land Management found that rivers on public lands--which support about 90 percent of the biological diversity in an arid place like Arizona--"have continued to decline and are considered to be in their worst condition in history." Livestock grazing was identified as the chief cause. Even if livestock were removed entirely from rivers, over the long term, only about 65 percent of rivers on BLM land would recover, scientists found. In a 1999 paper in The Journal of Soil and Water Conservation scientist Joy Belsky assessed 143 government reports and peer-reviewed scientific papers on the effects of grazing along Western rivers. (The effects of grazing in upland areas are not as severe, but in our part of the world result in wholesale conversion from ocotillos and saguaros to creosote and prickly pear, according to a study by Ray Turner of the Desert Laboratory in Tucson.) "We looked very hard for papers that showed benefits and couldn't find any," Belsky said. "There were papers that showed no effects. Usually the authors themselves pointed out that something had gone wrong, either with the research methodology or an unusual event, like a flood. Every paper that cited a positive or neutral effect, we cited." This may be sad news to people who still have fond memories of honeymoons spent on ranches, or even watching old Westerns. But it's hard to deny all the evidence that has mounted up in recent years. It's even harder when all that research is backed up by what you see out in the desert. Almost 10 years ago, I was lucky enough to spend a couple of days in New Mexico's Gila Wilderness with Bob Ohmart, a professor at Arizona State University. Like any good ecologist, Ohmart has the ability to turn the natural world from black-and-white Kansas into the Land of Oz. A landscape you took for granted suddenly seems richer, more complex, more alive. In the Gila, I learned how cattle grazing causes rivers to cut down into narrow trenches. I noticed the absence of young, green shoots of cottonwoods and willows, of the tall grass-like plants called sedges. I saw old cottonwoods barely hanging on by their gnarled gray, dying roots. I learned to question why trout weren't surviving. Ohmart grew up in a New Mexico ranching family. He even keeps a few cows on his exurban spread in Chandler, simply because he likes the grimy, fly-ridden beasts. But he's not about to whitewash the effects of these giant, clumsy animals that evolved in the moist environs of Asia. "I think we've got 30 to 50 years left before the damage is irreversible," says Ohmart. "I've had ranchers tell me, 'I've been on this ranch 60 years and this stream looks like it did 60 years ago.' But the changes are very gradual, with some trees falling and no recruitment of young willows and cottonwoods. You really don't recognize it unless you've got repeat photographs." You can still find scientists who work for the National Cattleman's Association instead of the National Science Foundation. You might meet anthropologists who find cattle barons fascinating and love to drink whiskey and eat steak with them. But it's getting harder to buck the science. Cattlemen point to studies showing that certain common species of fish, like the Rio Grande sucker, thrive in the warm water caused by stream deterioration. But if streams continue to decline, they go dry. According to Trout Unlimited, we are rapidly approaching the day when every single species of native Western trout, which require cool water in untrampled streams, will be on the endangered species list. The idea of living without bright flocks of tanagers is depressing, too. Carl Bock of Colorado State University showed that grazing has negative impacts on 17 of 43 neotropical migratory bird species. Simply changing how cattle graze doesn't cut it. Ohmart wrote in 1996 that "there is not a single grazing management approach that has produced consistent improvements of degraded riparian-wetland areas." This is from a book published by the Society for Range Management, by the way. We know the facts. Now it's time to act.
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