Each autumn in Southern California, a hot wind pushes out of the desert and over the mountains, racing down canyons before spreading out into the urban wilderness that surrounds the cities of Los Angeles and San Diego. It scours the hillsides of humidity and raises seaside temperatures, which barely hit 70 all summer long, into the triple digits.

And often, when that wind picks up, something else happens: A live wire drops into the dust-dry manzanita; a welder lets loose a shower of sparks among the sumac; a child drops the match he was using to torture ants and whoosh! Fire explodes across the chaparral-covered landscape, taking out everything in its path - stucco, shake-shingled roofs, minivans, horses, oaks and even the sinuous eucalyptus and string-bean palms planted by locals to make Southern California fit their idea of beauty.

This meteorological phenomenon, called the Santa Anas - not, some say, after St. Anne or the Santa Ana Mountains but rather in honor of Satan (Satana) himself - has been blamed for murders, suicides, divorce and destruction. It has also been known to drive sane people crazy, and none more so than an outspoken biologist and sometime firefighter named Richard W. Halsey, who in the aftermath of the winds and the subsequent infernos suffers from a peculiar kind of isolation: Almost everything everybody around him is saying about fire, he believes, is wrong.

"I get enraged," admits Halsey, a former high school biology teacher who quit 10 years ago to educate a broader audience about Southern California's plant communities. "I go into orbit. So many people out there create a sense of fear and misconception about the natural environment, which to me is just so wrong. We're disconnected enough as it is." The 53-year-old Halsey, who now runs a small nonprofit called the California Chaparral Institute, has dedicated his life to defending the chaparral against its detractors. He likens chaparral-haters to climate-change deniers and flat-earth believers. "I've chomped down on it," he says, "and I'm not going to let go until either I die or I can get some kind of validation, so that land-management agencies aren't proclaiming the need to cut it all down."

For context, he reads out loud from the latest issue of his quarterly newsletter, The Chaparralian, which features a picture of a miniature Smokey Bear in chaps: "Smokey Bear and wildland firefighters have been maligned long enough in California," he intones, mimicking a filmstrip voiceover from the 1950s. "It's time for the public and journalists to begin thinking for themselves and stop mindlessly accepting one of the most common group delusions in the last 25 years: Decades of fire suppression in chaparral are to blame for all the large wildfires in Southern California."

As Halsey sees it, this delusion has been loudly promoted by the chorus of experts who dominate the media every fall and winter. It begins well before the smoke clears: Authors, professors, botanists and biologists infiltrate the news reports and editorial pages, all of them fixed to the notion that fires wouldn't burn like this if we didn't allow our hillsides to become overgrown with brush. And while California burns, the reporters conclude, there exists a chaparral paradise south of the border, a world without professional firefighters, where small fires spark and then daintily smolder until they die away in the succulent green of all the young growth. Why can't we be more like Baja?

Listening to this, the sandy-haired Halsey becomes apoplectic. He sits in his basement office, firing off opinion pieces to the local newspapers, blasting out e-mails, trying to persuade the public of what he first figured out over a decade ago on hikes with his students: Chaparral, the idiosyncratic system of shrubs and oaks that dominates Southern California's protected wildlands, is not pine forest. It is not choked by dog-hair thickets; it does not need regular clearing by frequent fires. True: Hot smoke triggers the germination of some of its seeds. But the "elfin forest," as it was dubbed by mid-century naturalists, does not need to burn to thrive. Without human intervention, chaparral burns only once or twice a century. And when it does, it burns fast and hot in crown fires that leave only scorched earth behind.

Fire suppression, Halsey insists, has nothing to do with it.

When record-breaking Santa Anas blew across Southern California in late October 2007, so many fires sparked that Gov. Arnold Schwarzenegger literally had to revise his count upwards in the middle of a press conference; the final tally hit 14 before the wind abated and the burning stopped. One of those fires, the Witch, named for a local creek, licked the backyard of Halsey's home. Halsey and his two sons, 12-year-old Jake and 17-year-old Nick, ignored evacuation orders to defend it. A significant stand of mission manzanita, one of the oldest around, was destroyed on an incline just to his north.

Halsey's home survived in part, he says, because it sits on the top of a hill instead of in a saddle or canyon, which serve as funnels for wind-driven flames. But it also stands because he was there with a hose to protect it from embers. From his back porch, he can point to the blackened foundations of less-fortunate structures.

"I've heard rumors that they want to clear all the vegetation from this hillside," Halsey says of his neighbors. "But their house didn't burn because of that plant community. It burned because the house was in the wrong location. It wasn't designed properly. They had stripped the landscape all around their house, but it didn't help, because they've got this myopic view that it's all about the native landscape."

This narrow thinking, Halsey claims, has been largely sustained by one man: A geography professor named Richard Minnich, whose scientific papers on native chaparral have overtaken local discourse as thoroughly as cucumber vine climbs through chaparral during a rainy winter. In a landmark paper written 25 years ago, Minnich used satellite imagery to compare fire patterns from 1972 to 1980 in Baja with those just over the border. He concluded that on the Mexican side, where there was little organized effort to beat back fires, a lot of smaller fires had occurred causing little damage and no loss of life; in California, by contrast, huge swaths of land had burned in far more massive, and deadly, conflagrations.

"Yeah, they have smaller fires in Baja," concedes Halsey. At 6 and a half feet tall, he seems uneasily confined within his spacious home on this rainy day. "The reason they have smaller fires is because the ecosystem in Baja is absolutely devastated. What they've been doing down there - the grazing, the farming, the burning - is basically destroying the natural habitat to promote ranching."

"That's crap," answers Minnich. "California's past is embodied in Baja California. Opponents of mine deny that record, but denial is no way to proceed in science."

In part, Minnich is right: Early settlers in Southern California, as well as the Native Americans, practiced the same kind of land management Mexican ranchers do now, albeit on a much smaller and less-destructive scale. That changed in the early part of the century, when the federal government started cordoning off wildlands for protection. One of the things land managers protected them from was fire.