Getting To The Root Of The Matter

The middle Rio Grande south of Albuquerque is not much good for fishing, swimming or skipping rocks. About the only thing moving along the dusty river bottom are bulldozers keeping a floodway clear. The riverbed nowadays is merely an overflow drain used during heavy runoff periods. To minimize evaporation loss, the river's normal flow has been channeled into a broad ditch that rushes to a reservoir near Truth or Consequences.

The Rio Grande's one remaining grace is its salt cedar, the bountiful stands that tie down its banks. This slender tree flourishes where little else will. In the arid Southwest it serves more than an ornamental purpose, checking soil erosion, helping flood control, offering a windbreak and providing game with refuge. Its pink blossoms are a source of nectar for the area's honeybee industry. It was with these facts in mind that federal agencies planted the trees along the Rio Grande four decades ago.

But the Government thinks differently now. Its experts have come to believe that the salt cedars drink too much water, water better used for irrigation and other human needs. This is why the U.S. Bureau of Reclamation is currently seeking to gas—or more precisely spray, chop, bulldoze, crush and bury—roughly 75 million trees that grow along a 75-mile stretch of the river.

It is not easy to upset the tolerant people of this self-reliant land. They have let federal agencies test nuclear weapons and missiles in their backyard. But since the tree-eradication plan was announced there has been a furor. An unlikely coalition of state and federal legislators, civil servants, ranchers, beekeepers, hunters, fishermen, professors, housewives, students and conservationists has turned against the bureau that spends over $10 million annually trying to enhance New Mexico's admittedly limited water resources.

An imposing array of geologists, hydrologists, botanists, biologists and engineers declare that tree removal will not save an appreciable quantity of water. Instead, they insist, clearing the banks of the Rio Grande will lead to erosion, ruin the honeybee industry, wipe out dove nesting and wildlife habitat and hurt hunting, while destroying a vital greenbelt along the state's most important river basin. They also worry about the biological impact of spraying vast quantities of herbicide along a valley that nestles the state's major population and agricultural centers.

Last July a Reclamation Bureau contractor made a test spraying near the town of San Acacia, about 60 miles south of Albuquerque. The defoliant was Silvex, a close relative of a herbicide called Agent-Orange that has been banned from use in Vietnam because of its toxicity. By November some results were evident. Heavy spraying had failed to make a dent in the salt cedar thickets. However, two ranchers, whose cattle, pasture and children had been hit by the herbicide in the July spraying, claimed they found the defoliant surprisingly effective. The ranchers, Lewis Trotter and John Mayo, filed a lawsuit against the spraying contractor and administrative claims with the Government. They sued the sprayer for $500,000 damages to cover the alleged loss of cattle and injuries to their children who had been sprayed or consumed water from the contaminated pastures.

Department of Agriculture, veterinary and medical experts have documented Silvex contamination in some of the cattle and in the children. Although the children seem to have recovered, the federal investigation of the Trotter-Mayo case continues. The official bureau position is that the cattle belonging to the two ranchers may have been the victims of poison weeds or malnutrition. This explanation may be inadequate, since the bureau has no evidence that the contaminated children ate any weeds or were undernourished.

After 15 years of testing, federal research has failed to find a herbicide that eliminates salt cedar. "We've tried everything," says Dr. Paul Quimby of the Department of Agriculture research lab in Los Lunas, N. Mex. "The problem is that after the foliage drops off sprayed trees, protective quiescent buds suddenly are stimulated to grow. This defense mechanism keeps the trees alive." And the defoliation at certain times of the year scatters seeds, which only spurs the growth of new trees.

This explains why the bureau must supplement spraying with mechanical devices—plows that sever roots, rotary choppers that cut down small trees and the monstrous Maiden brush cutter that chews up trees in its path and spews them out as kindling to be mopped up by bulldozers. Continued maintenance necessary to check the regrowth of salt cedars along the 75-mile stretch of the Rio Grande would cost $100,000 annually.

There is no proof to date that clearing the banks of the Rio Grande will save water. Even after spending $1.8 million to remove 55,420 acres of trees along a 200-mile stretch of the Pecos River, the bureau lacks real proof of water salvage. Clearing of another 15,000 acres along the Pecos is being held up by lack of funds. Meanwhile the U.S. Geological Survey is trying to determine if clearing the banks actually saves water. Normal variation in stream flow, changes in the water table and evaporation complicate any such study.