Intentionally set fires may bring back haze

The smoky haze that blanketed Tucson this week may become a periodic nuisance here as increasingly larger chunks of the mountaintop forests around the city are deliberately burned.

Some of the smoke that blocked our mountain views this week traveled more than 1,000 miles - from southern Mexico and possibly Central America - to get here. By yesterday afternoon, most of it had been blown farther east.

But smoke from large ``prescribed burns'' in the mountains around Tucson will occasionally drift into the city in the coming years as federal land managers try to thin forests that are unnaturally dense and overgrown from decades of fire suppression, said Thomas W. Swetnam, a University of Arizona tree-ring researcher.

``If we start burning the Rincons, the Chiricahuas, the Catalinas and the Pinaleņos at the scale they need to be burned, there's going to be smoke coming into Tucson - it's going to be hard to avoid,'' said Swetnam, an associate professor of dendrochronology.

``People are going to be upset, and there's going to be a debate,'' he said. ``How much smoke are we willing to tolerate in the name of forest health and ecosystem restoration? I would hope that people would be tolerant.''

In Southern Arizona, the U.S. Forest Service plans to burn about 5,600 acres this year, and that number is expected to rise in coming years, said Ted Moore, fire management officer for the agency's Santa Catalina ranger district.

On July 1, Saguaro National Park is planning a 2,000-acre burn - the park's largest prescribed fire ever, said fire management officer Chuck Scott.

The fire will be on Mica Mountain in the Rincons, east of Tucson. It will burn in ponderosa pine forests at the 8,000-foot elevation and down into oak and manzanita at 5,000 feet.

Next year the park plans to burn 3,000 to 3,500 acres in the Rincons in a single fire. If these fires are successful, the size of the park's annual prescribed burn may be increased to 5,000 or 6,000 acres, Scott said yesterday. Up to 80 percent of the forest in the Rincons needs to be burned, he said.

``Ideally, if we could look at 5,000 to 6,000 acres a year, I think we'd be doing real well,'' he said.

Moore said the Forest Service works with the Arizona Department of Environmental Quality in an attempt to select weather conditions that keep the smoke from prescribed fires out of Tucson.

``But there may be days when smoke drifts into the city, and people may have to see some smoke in the future in order for us to get the forest back into a healthy state, like it was 100 years ago,'' he said.

The wildfire experts spoke yesterday morning during a news briefing at Sabino Canyon.

Moore warned again that El Niņo-generated weeds, grass and brush are expected to trigger a ``very active'' wildfire season at lower elevations until the monsoons arrive. There's a chance that the summer rainy season, which usually starts in early July, may be delayed or weakened this year by El Niņo, he said.

High elevations like the top of Mount Lemmon are still moist from all the snow that fell over the winter. But south- and east-facing slopes below 6,000 feet already are dry enough to burn, he said. Eight wildfires already have charred small patches in the Catalinas this year.

Abandoned campfires are blamed for about 60 percent of human-caused wildfires. No fire restrictions will be in place in the Coronado National Forest this Memorial Day weekend, but Moore urged campers to use caution.

Photo by Bruce McClelland, The Arizona Daily Star

The Forest Service's Jim Anzalone and Pete Michaelson train for the fire season.