Fire an ecological horror — or maybe not

Assessing Los Alamos damage

Blackened trees towering over Los Alamos, N.M., serve as symbols of ecological damage that ecologists say could last decades or centuries.

While the 1988 fire at Yellowstone National Park today stands as an ecological success story, some scientists and forest managers around the Southwest say the Cerro Grande fire will be an ecological disaster for a substantial part of the 47,000 acres burned.

Their view is not unanimous. Some environmentalists argue that this fire, like many others, will be beneficial, leaving patches of healthy ground that alternate with blackened patches.

But the prevailing view among fire ecologists in the Southwest is that the Cerro Grande fire will or could cause long-term damage to thousands of acres of habitat for imperiled species such as the Mexican spotted owl, the northern goshawk and the Jemez Mountain salamander.

The fire is also likely to leave behind what one U.S. Forest Service biologist calls a "biblical-like" wave of landscape erosion.

The erosion could lead to massive summertime flooding that could send tree branches and toxic and radioactive wastes through the canyons that fan out around Los Alamos. Eventually, the debris and waste could push into the town itself and go into the tributaries of the Rio Grande.

When the Yellowstone fire occurred in 1988, some scientists and members of the general public reacted negatively to the sight of thousands of blackened lodgepole pines. The fire consumed about 1 million of the park's 2.2 million acres.

But by 1994, researchers had found that vegetation in most burned areas had recovered quickly.

Water flows increased in many streams without the severe erosion that people had feared. Mammal populations stabilized or grew. More than enough lodgepole seedlings were growing to replace the trees that had burned.

The Cerro Grande fire won't repeat Yellowstone's experience because, while the fires were similar, the ecologies and ecological histories of the two landscapes are different, several ecologists said.

Thomas Swetnam, director of the University of Arizona's tree ring lab, predicted last week that many of the burned New Mexico pines won't regenerate for several centuries or even longer.

The park and the hills around Los Alamos suffered "crown fires," in which the flames lashed out at the treetops.

Yellowstone's lodgepole pines long ago adapted to crown fires. Their pine cones stay closed for 100 to 200 years. They depend on the fires' heat to open them up so they can release their seeds into the ground.

But at Cerro Grande, crown fires are, in biological time, relative newcomers. So is much of the vegetation that has built up on the mountain during the 20th century.

The ponderosa pine cones are already open and spread their seeds every year. But when fire burns through the treetops, it destroys the seeds, said Wally Covington, director of ecological restoration at Northern Arizona University in Flagstaff.

Lodgepoles and other closed-cone pines also have a thick insulation layer of woody, corky material that keeps fires from heating them to lethal temperatures. Ponderosa pines never needed this layer because until recently, they never got crown fires.

"It's just completely different strategies," Covington said. Tree rings studied at UA show how the Jemez area's fire behavior has changed so radically.

A century ago, the Jemez Mountains in the area where the Cerro Grande burn started was a huge, open meadow, with grasslands and only a small number of trees, said Swetnam, the lab's director.

Those grasses frequently drew 1- to 3-foot-high fires that ran quickly through the forest understory, without burning the treetops, Swetnam said.

But the tree ring studies showed that the low-lying fires declined sharply during much of the 20th century.

The reasons: Sheep and cattle grazing, starting toward the end of the 19th century, gobbled up the grass. Fire suppression by the U.S. Forest Service also allowed trees to invade in place of the grassland.

Now the trees are "completely taken out" by crown fires, Swetnam said.

"The intensity levels (today) are orders of magnitude higher than the surface grassland fires," he said. "Once heated, the volatile gases and other materials come out of the leaves. They literally explode. It creates its own wind, and becomes a firestorm."

Gambel oak and aspen trees that thrive in open country could come into these hills and create good elk habitat, he said. The area already has one of the Southwest's largest elk herds.

But overall, he's somewhat pessimistic, Swetnam said last week.

"This kind of fire, the landscape is not adapted to. In that respect, it is harming a lot of species" that depend on the pine trees, said Stephen Pyne, who teaches environmental history and fire ecology at Arizona State University. "A fire is not some kind of automatic lethal poison where if someplace burns, it is ruined forever. What makes it poisonous is the dosage."

The threats last week prompted federal officials to import an ecological SWAT team to assess and try to put a band-aid on the damage.

More than 40 specialists in soils, plants, geology and hydrology from Idaho to Arizona are roaming the forest. They hope to put into place an emergency plan within the next few weeks, if not by this week, to stave off the erosion threat.

With trees and low-lying brush stripped from much of the land, biologists are bracing for what the U.S. Forest Service's Bill Armstrong from Espanola, N.M., calls a "biblical-like" erosion threat from summertime storms.

The threat is that runoff from the monsoon rains will speed down the hills and into the canyons.

Then it could carry into Los Alamos and into the tributaries of the Rio Grande dead branches, sticks and other forest debris, along with toxic and radioactive wastes dumped into the canyons over the past half-century at Los Alamos National Laboratory.

Charles Jankiewicz, a Forest Service biologist, said the fire had burned its hottest and most damaging on about 25 percent of the 47,000 acres.

A Tucsonan during the late 1960s through the mid-'70s, Jankiewicz said the flood damage could resemble the carnage that the Santa Cruz, Rillito, Pantano and other rivers visited upon Tucson homes in the days before Pima County officials built thick walls of soil cement to line the riverbanks.

"The worst potential damage to life and property in Los Alamos will come in the next 18 months," he said. "The soils will repel water on thousands of acres on steep slopes. They will shed almost every drop of water."

Not everyone views this fire as a disaster for the forests. Rex Wahl, director of Santa Fe's Forest Guardians, said it's kind of funny that people will place human values on the forests and automatically view their burning as destructive.

"The forest doesn't give a damn," said Wahl, whose group opposes most or all commercial logging of the forests. "It is always going to be a forest. It will just be a different kind of forest.''

Sam Hitt, the group's founder, said he found the effects on the land — as opposed to the town — to be "very positive" when he flew over the area recently.

"The tragedy was the way it went through Los Alamos," Hitt said. "But what I saw was a typical fire, that jumped ridge to ridge. It heated up some areas and cooled in others.

"Despite the colorful adjectives, the way the fire runs through the forest is to leave behind a complex mosaic of habitats. It did what a fire is supposed to do in this kind of forest — it crowns out, skips a ridge and likely burns some areas.''

But a few miles north of Los Alamos on the Santa Clara Indian Pueblo, the burning of trees isn't just an ecological issue.

Tribal officials for the past week have watched fire scorch ponderosa pines along the bottom of five miles of Santa Clara Canyon.

That's the source of their drinking water and the hub of their fishing- and tourism-based economy.

"The public needs to understand that this is not just a piece of land. '' said Alvin Warren, the pueblo's fire information officer. "We operate the canyon as a recreation area for tourists. Our artists and craftspeople depend on recreation.

"It's our hospital, the source of our traditional medicines and plants. It's like a church, for our traditional practices.

"Certainly it will disrupt our economy for many years to come," Warren said.

Chart: Los Alamos-area fires

Graphic by The Associated Press: How prescribed burns work