Out There Guy Quizzes The Experts On This Summer's Fire Season. By Kevin Franklin EL NIÑO ISN'T dead yet. All winter long we here in Tucson got to watch as other parts of the country endured floods, ice storms, power outages and a host of other disasters. For us, it just rained a little more than usual and we got to look at all the pretty flowers. But now it's our turn: It's going to be a summer of fire. The rain that spurred all the growth of our spring wildflowers also brought record grass growth, as anyone with a yard can tell you. Now all that grass is dead or dying, and nothing likes to burn more than dry, dead grass. The clincher for the Sonoran Desert is that the preponderance of grass we have is non-native. Many of the amber waves covering the desert originated from places like southern Europe and Africa. Saguaros, palo verde and cholla have not evolved to deal with the fire those places get, and tend to boil and blow up when subjected to it. Our native grasses, like sacaton, tend to be bunch grasses that grow in clumps. When they ignite, generally only the relatively small area around them burns. In a natural situation, there just isn't enough fuel to carry the fire across the desert. These new grasses, like buffel grass, Lehmann's lovegrass and red brome grow as mats. Fires can race along them and afflict large areas. "If it turns hot and dry we've got lots of grass out there, and we'd expect a very active fire season in the Sonoran Desert where typically we might not have that at all," says Kirk Rowdabaugh, state lands Fire Management Division director. Fire is beginning to change the face of our desert. "Look at the kind of fire activity we've had just in just the last five or six years, and the kinds of mortality we've been seeing in the charismatic species like saguaros, ocotillo and other cactus species we identify with the Sonoran Desert," he says. "We're killing them left and right. We know that historically they could not have evolved in the kind of fire environment they've been subjected to in the last five or six years." Rowdabaugh says controlling the non-native plant population is a confounding problem. "Once they're here, how do you get rid of them? Prescribed burnings won't work because these things are aggressive pioneer species. They love disturbed sites. In fact, they're more aggressive than the native species. Once we get a fire, what we get right back is more of these exotic annuals--in a big way," he explains. Just how bad this fire season is going to be remains to be seen. "The fire danger," says Mark Hostetler, a U.S. Forest Service fire dispatcher, "is determined by a fairly complex formula of fuel moisture, fuel quantities, wind and daytime temperatures. There are certainly fuel indicators that show it could be an active fire season." Hostetler has been fighting wildfires for 20 years. "If it gets real hot and the fuel dries out, fires could break out easily," he says. "The key is to control ignition sources. Before the monsoons get here (and lightning strikes) all the fires are going to be human-caused." This means it's up to each of us to protect the desert by being very careful with potential ignition sources, like cigarettes. Not everywhere is going to have a fire problem this year. The grasses have the potential to make things sizzle in the desert, but all the rain has given the trees in the mountains a good soaking. That means there probably won't be much in the way of big fires in the mountains this year. "If you're above the rim on the forested land, this year looks great," Rowdabaugh says. "Our 1,000-hour fuel moistures are as high as they've been in recent memory. We don't expect to have much, if any, fire season in the forested regions." Even the lower elevations might not burn as much as one fears, given all the grass. "What we've got is potential," Rowdabaugh says. "Fire behavior is a result of fuels, weather and topography. The topography doesn't change much and the fuels change from year to year. We do have bad fuel conditions; but we really don't have a fix on what the weather is going to be. It's been a late spring and hasn't gotten really hot yet." The key to determining fire weather is dew point. "We track dew points," Rowdabaugh says. "Our typical benchmark is dew points above or below 30 degrees. When it gets below 30 degrees, the air is really quite dry. Then our nighttime humidity recoveries can be pretty weak and so our fires can burn well through the night. When the dew points stay above 30 degrees, we tend to get pretty good nighttime recovery and the fire tends to lay down at night and gives us a good chance to get control of these things during the nighttime hours." But even if things stay under control this summer, that doesn't mean it's over yet. Next summer may be the time the piper really demands payment, especially for the forested mountain areas. "The other interesting thing about El Niño is that it has an influence that lasts more than one year," says Thomas Swetnam, associate professor of dendrochronology (tree ring study). "It looks like historically you have some lags that go one for several years. The key situation for the really bad kind of fires--where you get catastrophic fires causing high-intensity fires both in the desert and in the mountains--is where you have a couple of years of wet conditions then cycle back into dry conditions." Bust out the marshmallows...there's just no escaping El Niño.

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