Experts line up on all sides of the tree-grass debate

  • Controlled burn killed invading ponderosa pine and old-growth juniper

    J.D. Marston
  • Stephen Pyne

  Essay by Ed Marston





If only Sid Goodloe had confined himself to his six or so square miles of private property. Then his would be a straightforward story about the rejuvenation of a piece of exhausted land.


But Goodloe doesn't stop at his boundaries. He believes range restoration should extend to 63 million acres of former grassland afflicted by piûon-juniper across the Southwest. That is almost 100,000 square miles - about the size of a typical Western state.


When Goodloe moves off his land, he runs into people who are eager to challenge his world view: scientists who say his work doesn't support the sweeping claims he makes, environmentalists who see him as seeking grass at the expense of forest, Native Americans and Hispanics who treasure the piûon trees he would extirpate, and people who are repelled by the methods he uses to shove the land back into what he says is its proper ecological state.


Professor Emeritus Ron M. Lanner of Utah State University's Forest Resource Department looks at the same kind of landscape as Goodloe, but instead of an invasion he sees cattlemen and range scientists stealing woodlands:


"It took me a while to realize that what a forester regarded as a tree species successfully regenerating in its native habitat, a range manager considered an invader."


In a paper titled, "What Kind of Woodland Does the Future Hold?" Lanner argues that piûon-juniper are despised because they can't be sold to a sawmill. If piûon-juniper had cash value, the way grass does, Lanner says, ranchers would be happy to see piûon-juniper trees growing on their land.


Lanner rejects talk of soil and watersheds lost to invading trees. Those arguments, he writes, were first floated in 1973 by the U.S. Forest Service in Utah. "There was not a shred of evidence to support it in 1973, and there is none now."


It is not just the Southwest where trees battle grass. In the Great Basin of Oregon and Nevada, juniper has taken over large expanses of former grassland. There is no disagreement about juniper's expansion. But in a peer-reviewed paper, A. Joy Belsky, an ecologist with the Oregon Natural Resources Council, writes that it is impossible to draw any conclusions about the effects on water, soils or wildlife.


Juniper, she says, has spread to more productive sites, but so what? Regarding the kind of brush removal work Goodloe has done, she says, "Most experimental studies showed that piûon-juniper removal did not increase water yield." Finally, "Juniper may also have fewer effects on water infiltration and erosion than livestock, which reduce vegetative cover and disturb soils with their hooves."


William A. Dick-Peddie, professor emeritus of biology at New Mexico State University, and author of New Mexico Vegetation: Past, Present and Future, is even tougher on cows than Belsky.


"I think juniper follows overgrazing. The site gets opened up. It causes erosion and gullies." The erosion, he continues, concentrates what water there is in gullies. So instead of grass growing over the entire landscape, trees grow in the gullies that have captured the water.


As far as Dick-Peddie is concerned, fire plays little or no role in the spread of trees into former grasslands. "The importance of fire has receded in scholars' minds," he says.


But Julio Betancourt, a senior scientist with the U.S. Geological Survey at the University of Arizona's Desert Laboratory, says, "I disagree that there's any consensus at all about the unimportance of fire and the importance of grazing. Ecosystems that have enough grass to carry fire can carry grazing. Anywhere you can enhance fire, you should do it."





These disagreements have to do with on-the-ground interactions among livestock grazing, fire, grass and trees. But talk to the scientists for any length of time, and you find that the issues broaden wildly, and become involved with climate change, the effect Indians had on the land, the rate at which the glaciers receded, and the temperature of the Pacific Ocean.


Questions of landscape health and change are not tightly defined, or tightly confined. Ecologists, botanists, hydrologists, range scientists, climatologists, paleoecologists, archaeologists all have valid views. But each discipline looks through a different lens. Only rarely can their separate contributions be added up to reach a conclusion.


Betancourt, for example, is a paleoecologist who has done extraordinary work analyzing packrat middens and then painting a picture of the Southwest's changing landscape over the past 40,000 years. His research tells us that not so long ago the Sonoran desert was covered by spruce and fir forests that now survive only as relicts on top of so-called sky islands.


From Betancourt's perspective, the last ice age is close - only "a few tens of generations away" when measured in terms of the piûon-juniper trees, which can live 500 years or more. When he's not studying packrat middens - leaves and needles and rocks and bones gathered over the last 40,000 years by generations of packrats and held together by solidified urine - he's examining how piûon and juniper trees die. The P-J forests tend to die all at once, catastrophically, as result of drought.


Betancourt draws links between these sudden declines and the effects of Pacific Ocean temperatures on the Southwest's climate. If you look at the region through Betancourt's eyes, Goodloe is fighting immense forces, like the circulation of the major ocean currents, as he strives to restore and then maintain his grasslands.


Karen Adams also takes a long view, but hers involves human influence on the land. She is a Tucson botanist who also works at the Crow Canyon Archaeological Center at Cortez, Colo. She has visited Goodloe's ranch and praises him for "bringing back the balance of warm and cool season plants. He's healing the arroyo. He's doing the right thing."


But whether he is acting rightly or wrongly in the short term, she is pessimistic about his ultimate success. She suggests that the damage Goodloe's land suffered goes way back. "I'm beginning to think that prehistoric people weren't as conservative as we think they were, and that the land was still recovering when Anglos came here."


Part of that ongoing recovery may be piûon-juniper trees taking back land Indians had cleared of trees. Or, she says, what looks like an invasion caused by lack of fire may be driven by climate change that is forcing out grass and encouraging trees.


"There are natural reasons piûon-juniper move up and down (the landscape), plus there are the past effects of humans. It's complex." Goodloe is fighting forces so powerful, she says, that the large-scale chainings of the 1960s protested by many environmentalists "have done absolutely no good." She is fatalistic about Goodloe's mix of fire, herbicides and short-duration grazing to keep back the grass: "Bless his heart. He can probably do that the rest of his life."





When looked at from the perspective of climate change, Goodloe and his bulldozers and matches become insignificant. But Goodloe - who believes that rising carbon dioxide levels are accelerating tree growth on his land - doesn't know he's insignificant.


When it comes to what the landscape should look like, he thinks and acts big. The West has its land-grant universities and federal land management agencies and their research stations. But if there is a long-term scientific experiment in land restoration and manipulation that comes close to Goodloe's, no one has ballyhooed it.


In fact, Thaddeus Box, a retired range professor from Utah State University, says, "Incredibly enough, the science is relatively primitive. Ranch-size plots like Goodloe's don't exist."


Instead, the scientists pose, and answer, narrow questions. In summer 1994, at a piûon-juniper research conference in Flagstaff titled "Desired Future Conditions for Piûon-Juniper Ecosystems," there were lots of scientists and land managers - good people doing good work. But they weren't interested in the big picture. The specialists stayed close to their experimental plots or their juniper-loving insects or the oils in Pinus edulis. Goodloe was the only speaker on the program who tried to tie together an economy, an ecosystem and a theory of the land.





How then do we decide whether the Southwest should be a grassland or a woodland? If, on this subject, science is a tower of Babel, on what foundation do landowners and the public base strategies?


A partial answer came out of the small town of Joseph, Ore., this winter, when Goodloe and fire historian Stephen Pyne of Arizona State University participated in a three-day literary workshop called Fishtrap.


Pyne, author of Fire in America and of the more recent World Fire, and Goodloe showed slides, gave talks, and interacted with an audience rich in fire experts from land management agencies.


Pyne says, "Goodloe's is as good an explanation and a solution as anyone has come up with." He warns against broad conclusions because, he says, each piece of land is unique. But he also says, "I'm convinced from reading the historical record that the Southwest was dominated by grasses, and now it's dominated by woody plants."


When Pyne talks of woody plants, he doesn't mean just piûon and juniper: He includes the near-sacred saguaro among the brushy invaders. Most people, he says, don't think of a saguaro or its fellow cacti that way. "But when the cactus rots, you realize it is also a woody plant."


Perhaps because he's a historian rather than a range scientist or ecologist, Pyne isn't very dogmatic about theories, including his own. He quotes with approval Norm Christensen, a fire ecologist at Duke University:


"Norm likened fire ecology to holy scripture - they can justify anything they want." Pyne continues, "It's not a lab science. The experiments are always turning out different. It's the same with climate modeling, water infiltration measurements, hydrology. They can't replicate the work.


"God bless the researchers. They're working hard. But it's not possible."





If hard, experimental science won't point us toward a landscape, what will? Pyne, a historian who doesn't even fully trust his own discipline, hedges. He says history provides only a rough guide. "We can't go back. Too much has changed, like introduced species. We have to accept what is here now."


Even if we could somehow visit the past, Pyne says, it wouldn't provide a definitive answer. "We know that nature created an enormous variety of landscapes. But it doesn't tell us which to choose."


He rejects the ecological view that says the more species the better. And he rejects the idea that we should simply let the landscape tell its own story, by letting wildfires burn and by generally letting nature take its course.


"At some point, you have to quit being an ecologist and saying that nature has no values - that everything in nature is equally good." Nature may have no values, but "you have to recognize that humans do have values, and that they do exercise them."


Despite its limitations, Pyne believes history provides the best guide we have. "There is general dissatisfaction with the landscape today, but the early explorers and pioneers liked the landscape they found, and that is why they settled there. They liked the grass up to the stirrups, and the open, grassy forests and the wildlife."


That, he says, is the landscape he would choose, though he knows others would make different choices. "Bertrand Russell said people like the natural world they grew up with. So if you grew up with piûon-juniper, you get alarmed at the idea of removing them." Pyne could add that if piûon-juniper dominated the West when you moved to the region, you might also want to hang on to it.


However difficult, he continues, we have to call the shots. "We're brought back to human values. We're living on an existential earth. We have an earth that can take lots of shapes. It argues for prudence, for recognizing our level of ignorance. But I don't see how we can escape the need to shape the land.


"The real future of environmentalism is in rehabilitation and restoration. Environmentalists have told the story of the Garden of Eden and the fall from grace over and over again. But we haven't yet told the story of redemption," Pyne concludes. "Now we need to tell that story." n