"Any idea of equilibrium—forget it," Falk says. "Fire, climate, and insects—all of these are converging on the dynamics of the forest. It's a pinball. Nothing is standing still." The best strategy is to get wildfires working again as freely as possible. Triggered in times of heat and drought, abating in periods of wet, fires naturally keep pace with the environmental flux of the future.
Will the hands-off advice be taken? Falk makes a few turns through the warren of the lab and emerges in the 110-degree sunlight of the football field. Taking the steps two at a time, he climbs to the topmost row of seats, in the spruce-fir zone of the stadium, as it were. He points to a sky island 35 miles south. You can see broad, lazy lines of white smoke around the waist of the mountains and hotter, darker whorls above the mixed-conifer belt. The Santa Ritas were burning, but a thousand firefighters were pushing back.
Wildland fire use, in the terminology of the Forest Service, means not doing anything to put out a fire. The term applies only to naturally ignited blazes. It's like prescribed burning without the human agency. The agency may opt to "use" a natural fire to clean out an overgrown forest. Last summer the Coronado National Forest adopted wildland fire use for the entire sky island system. Previously the policy applied only to wilderness areas in the highest and remotest parts of the mountains. Under the policy, managers could, strictly speaking, allow a fire in the Catalinas or the Rincon Mountains, the ranges adjacent to Tucson, to burn right to the city limits.
The Forest Service calls its border with Tucson the wildland-urban interface, and in practice no fire is allowed to get near it because of the roads and homes there. According to the Coronado Web site: "Approximately 34,000 acres of the Forest are in urban interface areas. In the Tucson area alone there are approximately 60 miles of interface. The mixture of houses, flashy fuels, and brush fields in full view of a large metropolitan area adds significantly to the challenges and complexity of even the smallest wildland fire." Another Forest Service document notes: "Most wildland-urban interface fire problems are in ponderosa forests because these forests are so widespread, so pleasant to live in, and so extremely fire dependent."
Tucson's suburbs having sprawled to the Santa Rita range, a big problem arose last July 7, when lightning sparked a fire on Florida Peak. The Santa Ritas had not burned extensively since 1892. Because flames travel more slowly downhill than up, the Forest Service had a little time to figure out what to do. Wildland fire use was considered and rejected: The pre-monsoonal conditions were too dry and the urban interface too near. A crew of about 80 was sent into the mountains. With the blaze still relatively small and superficial, the firefighters began to dig a containment line around it, scraping off the burnable vegetation, while aircraft dumped water and chemical retardant. Then a strong north wind came up, and the fire crowned. The local crew was pulled off the mountain. A "hotshot" regional team came in with a more muscular and more conservative containment plan. The rugged, high elevations of the Santa Ritas would be permitted to burn, and key structures in the urban interface would be protected by controlled fires on their perimeters.
The two pressing obligations on the west side of the range were Madera Canyon, a resort community and popular bird-watching area, and the Mount Hopkins telescope. Fortunately, vegetation around the houses and lodges in Madera Canyon had been thinned in recent years. Firefighters prepared to burn out more brush and trees. On the east side of the Santa Ritas, which is sparsely populated, bulldozers dug lines and helicopters torched large swaths of the oak and juniper zone.
The temperature in Tucson had topped 100 degrees for 30 successive days, approaching a record. Although clouds swelled over the desert every afternoon, they fomented more wind than rain. It must have been scary at the telescope facility, which is perched over a deep canyon. The Forest Service dared to post only engine crews, who could jump into their vehicles and flee. If the fire took hold in the canyon, it could charge up the slope in two hours.
A week after starting, the Florida fire, including its man-made satellites, covered 20,000 acres. Officials estimated that 55,000 acres would burn. But on July 16, with 986 firefighters on the scene, the monsoon arrived, and an inch of rain fell. The fire lay down and the fight went out of it. About 23,000 acres would burn. Owing to the hopscotch pattern of the flames, the destruction in the mixed-conifer zone was less than feared. So the Florida fire turned out to be a pretty good fire.
The human containment effort cost $8 million.
You don't hear much about the Rincons, whose foothills are on the eastern edge of Tucson, because residents and tourists are drawn to the Catalinas, on the north. The Catalinas are the more attractive range, bold and blue, like a mural for the city, while the Rincons are lumpy and out of the way. The Catalinas have a paved road and bustling summer colonies and a winter ski resort; the Rincons have horseback-riding and hiking trails.
The Forest Service built a firehouse high in the Catalinas for faster response. When the service built a lookout tower in the Rincons, the goal was to look for smoke in the other range. Because of poor access, it was hard to combat fires in the Rincons. But the most important difference between the two ranges is that the Rincons are the only sky island supervised entirely by the National Park Service.
The Park Service took over the Rincons in 1937. Guided by progressive conservationists, its managers embraced the ecological benefits of fire before the Forest Service did. As a result, the era of aggressive fire suppression in the Rincons did not last long. Between 1937 and 2000 there were 414 fires on Mica Mountain, a high point in the range. Six were prescribed burns; 25 were accidental, human-caused fires; and the rest were due to lightning. Only the accidental blazes were extinguished. None of the fires were huge. The Catalinas had almost no fires to report during this period, and then were wracked by the Bullock and Aspen fires in 2002 and 2003.
David Hodges called the Park Service's handling of fire in the Rincons "the best fire program in the nation" and "a lesson in how to get back to a natural regime." Said Don Falk of the tree-ring laboratory, "The forest is more open—healthy—compared to the Catalinas."
"This area does emulate an uninterrupted fire regime," said Falk's colleague Calvin Farris, who is writing his Ph.D. dissertation on the Rincons. Some of the pine groves on the rocky east side of Mica Mountain have been scarred 10 times since 1925—scarred but never killed. "Lightning hits it directly, and fires climb to it from elsewhere," said Farris, who described "big surviving trees and grass below, on an open forest floor." Mica Mountain was worth visiting.
If you hike the Rincons in summer, you must start early in the day, or the heat will stop you. The elevation gain from the trailhead at Happy Valley to the summit is 4,000 feet, and steep all the way. For the first hour you're in high desert. With a hurried eye, you notice yucca and manzanita giving way to scrub oaks. There are charred stumps in the glittering soil (that's the mica). You see a Chihuahua pine, wizened and short, and then taller oaks. Shade commences halfway. Before noon the first thunderhead, ballooning over the still-distant peak.
Big ponderosa pines here and there. A cool sky island wind snatches your breath away. Other mountains have climbed into view when you turn around and look. It's getting more and more beautiful. A prairie falcon is rising and dipping along the line of an invisible wave, a dark particle of light traveling straight from sight.
Nearing 8,000 feet, you come to the ideal glade. Well, not the ideal, because there is no such thing in nature's cauldron, and besides the pines in the glade are a bit young, maybe 100 years old. But they are gracefully separated, with no lower limbs, and the carpet of needles and ferns at their feet is soft enough for a children's birthday party. Wander around. If you check a tree at random, it's there, the sky island badge, the catface scar.
