Chaparral : SDSU Strives to Cut Flaming Villain Down to Size

The old campfire song “Boomdeada” starts off with a melodic, “I like the forest, I like the chaparral.”

But chaparral has gotten a bad name in recent years because of the ease with which it burns during brush fires. Scenes of the native shrub bursting into flame across thousands of acres of both backcountry and urban brush have been seared into the memories of Southern Californians, many through firsthand tragedies this summer.

Researchers from San Diego State University are busy studying chaparral to come up with better ways of managing it--both to prevent future major conflagrations and improve on chaparral’s value to the region’s ecology.

The goal is to control chaparral growth--a valuable water-holding ground cover and resource for wildlife--so that vast tracts of brush will not all burn at the same time if touched off by lightning or other causes. The technique would include seasonal burns and removal techniques so that, for example, a stand of mature chaparral that might blaze fiercely exists next to a group of immature shrubs that are more difficult to burn.

Creation of such an age-mosaic pattern of chaparral over a period of years throughout Southern California could help cut down large firestorms and improve the image of the plant. That pattern traditionally existed in chaparral areas before large-scale ranching and other uses became common in backcountry areas more than a hundred years ago.

San Diego State researchers believe themselves fortunate in having a remote site where brush fire and other ecological studies can be carried out with minimum environmental risk and without intrusion from urban-related factors.

The university operates a 3,000-acre biological field station called Sky Oaks in the dry mountain country of San Diego County northeast of Warner Springs, in the shadow of the county’s tallest peaks, topping out above the 6,000-foot level.

The field station is crisscrossed with streams and canyons, and an abundance of wildlife allows for a variety of ecological work in addition to the fire prevention studies. Graduate students at present are investigating the commercial possibilities of growing oaks and eucalyptus trees.

“We’re incredibly fortunate in having such a wide diversity to study,” Walter C. Oechel, director of the university’s systems ecology group, said. Almost $1 million from the National Science Foundation funds a large part of the research.

The growth cycle of chaparral depends on periodic burning through an area of brush, Steve Sparks, one of several graduate students working on fire-related research, said in an interview at Sky Oaks. Chaparral seedlings sprout only after a fire creates certain changes in soil nutrients, perhaps as a consequence of ash from burned shrubs settling into the soil.

After new chaparral grows from the ashes, shrubs will not sprout again until after the next conflagration. As various stands of shrubs mature, for perhaps 30 to 50 years, portions die and create underbrush, reaching the stage of peak flammability in the event of a future fire.

Indians living in chaparral-covered areas knew of the regenerative aspects of chaparral after a fire, and they routinely burned patches of mature brush in the late summer and early fall, Tim Cass, another graduate student, said. The new growth would prove more productive in attracting wildlife and thus prove beneficial to hunting, Cass said.

The same purpose would be served by lightning fires, Cass said.

“People living in the San Gabriel area of Los Angeles used to notice that small fires touched off during the summer might smolder for the entire season,” Sparks said. Such periodic fires would destroy some of the chaparral stands, leaving others to continue growing. So during any one blaze, certain areas would burn and others little or not at all, Sparks said, illustrating nature’s way of limiting damage while beginning new growth cycles.

What’s more, during certain times of the year when the moisture content of the air is higher, chaparral burns little if at all, Cass said. Only in highly unusual cases would fires cover thousands of acres as they do regularly today, he said.

However, the growth of national forests and the growing presence of rural homes and communities during the past 50 years brought about increased firefighting activity with the goal of suppressing all fires as quickly as possible.

For years, even if a fire broke out that, scientifically speaking, would be considered natural in rejuvenating chaparral stands--and would not threaten structures or communities--it would be put out as quickly as possible.

So the result, in far too many cases, has been vast tracts of chaparral all maturing and thus all vulnerable to fire at the same time. Therefore the fires that have broken out have burned far more acreage than they would have otherwise. Further, the hotter and more intense the fire, the more likely that oaks and other trees able to withstand smaller blazes will succumb to the larger blazes.

The last fire in the Sky Oaks area was in 1928, Sparks said. The Bucksnort Mountain range to the east contains 60-year-old chaparral, which would burn fiercely if touched off, perhaps as far as Ramona in the worst case, some 30 miles to the south.

“California has the most explosive fires in the world,” Sparks said, adding that the particular type of chaparral most common in the state is called “chamise” and is especially volatile.

The Laguna Mountain area, which had sprouted vast stands of chaparral over the years, burned in 1970, destroying 30,000 acres. At present, the chaparral is growing back uniformly across the entire acreage and could one day again prove ready for another major blaze. But the area is now the site of U.S. Forest Service experiments connected to the San Diego State research where age mosaics are being attempted. One side of a mountain is burned in a controlled manner to create chaparral stands of different ages, lessening the possibility of future fires getting out of control.

However, before such controlled burning can be attempted on a wide scale, more study is needed.

“If we do all the burning in off-season, that results in cooler fires with wetter soils that will form steam and perhaps change the way the seeds sprout and even perhaps change the character of the vegetation,” Sparks said. The majority of natural fires occur in late summer and early fall when the weather is hottest and driest.

From burns deliberately made on tens of acres over the past three years, researchers can learn in a relatively short period of time what the regeneration pattern will be.

“Because chaparral only sprouts once after a fire, you know what the pattern will be within a couple of years,” Sparks said.

In essence, Cass said the present research is geared toward refining the prescriptions for burn management. “Maybe in some cases we’ll find out it’s best not to burn at all but to try something different,” he said.

The research is geared predominantly to fire management in rural areas. For urban canyons rimmed by homes, such as San Diego’s San Clemente Canyon and the steep slopes north of Normal Heights, where more than 60 homes burned June 30, large controlled burns would be more difficult, Cass said.

“You might be able to do small burning in canyon areas to create a mosaic pattern,” Sparks said. But researchers are reluctant to recommend such steps because they are not yet fully comfortable with controlled burning in small areas, especially in the summer.

An alternative to urban burning would be clearing by hand using a mosaic pattern. In that way, the fire danger can be reduced without destroying all the chaparral and losing its erosion-control and wildlife-promotion benefits.