Fires and Ecology
Southern California’s dramatic landscape is naturally prone to damage from fire and wind. However, the potential for disaster from these two phenomena has exploded as development reaches farther into the region’s steep hills and canyons. Fortunately, native plant species are well equipped to recover from wildfire, and some human intervention can minimize the toll on wildlife.
Built to Burn
Much of Southern California’s native canyon and hillside flora are born in flame: Seeds of the chaparral germinate only after a brush fire has passed through. In an area prone to brief rains and long droughts, the leaves of these plants are coated with oily or resinous material to preserve moisture. The oils and resins are highly flammable. Here is a sampling of those plants.
CHAMISE: Member of the rose family. One of the most abundant chaparral shrubs and among the most flammable. Grows 4 to 8 feet tall. With ideal weather conditions, may resprout almost immediately after a fire, sometimes within a day.
SAGEBRUSH: Sunflower family. Many species exist in Southern California, but all have narrow, gray-green leaves and small greenish flowers. A highly flammable deciduous shrub, acts as kindling in spreading a wildfire.
MANZANITA: Heather family. Handsome shrubs with crooked, graceful, reddish-brown limbs. One common local variety, eastwood manzanita, sends up new shoots from the base of a burned bush.
Ready to Ignite: Moisture content of chaparral plants fluctuates according to seasonal rains, as chart shows. The lower the moisture, the greater the threat that the plant will burn.
Plant moisture as % of dry weight*
Reseeding and Rejuvenation
A variety of methods can be used to rejuvenate the growth of grasses across the burned bluffs and canyons of the Santa Monica Mountains. How hillsides will be reseeded and what native flora will look like over the next five years:
Aerial seeding: Helicopters or aircraft tankers drop grass seed onto wilderness areas.
Advantage: Works best in wide-open spaces.
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Hydro seeding: A soup of grass seed, mulch and water is sprayed through a hose from a tanker.
Advantage: Best used around housing.
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Hemp: Netting holds soil in place while grass sprouts and takes hold.
Advantage: Best for hillsides.
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Sequence of Regrowth
One year after fire
* Native grasses--generally fescue--and buckwheat flourish.
* Wildflowers and small cactuses dot the landscape.
* Clusters of coastal sage scrub pop up along hillsides.
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Three years after fire
* A highly flammable shrub, chamise, now up to 10 feet tall.
* Native shrubs, including lemonade berry, sage scrub and laurel sumac, cover canyons and bluff tops.
* Trees sprout in canyons and on bluff tops.
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Five years after fire
* Dense green chamise, up to 15 feet tall, covers hillsides.
* Grasses, flowers and shrubs are fully established in canyons.
* Trees, including willows, eucalyptuses and sycamores, are nearing mature height.
Wildlife’s Struggle
Coyotes, raccoons, rabbits, deer, squirrels, opossums and other wild animals have been displaced in the fires. Those that were able to hide in burrows have a chance of surviving. The traumatized are roaming in every direction in search of food--from dead snakes to smoked-choked birds and pet cats.
* Precaution: Residents are advised to keep cats and other small pets indoors and not to feed deer--especially hay or pellets. There is little chance of deer starving to death, although some will die from trauma, dehydration and shock.
* Winners: If the fire has any winners, they will be predators such as coyotes, owls, bobcats and mountain lions. They will feed on opossums, raccoons, birds, lizards and snakes.
* Restoration: Wild animals will return to the burned-out areas and flourish. Fires clear away old shrubs and grasses that have lost nutritional value with age, and animals will thrive on new growth high in calories.
SOURCES: “Fuel Moisture and Fire Behavior: An update,” Carol L. Rice and Robert E. Martin; L.A. County Fire Department; “Los Angeles Against the Mountains,” John McPhee; “Roadside Plants of Southern California,” Thomas J. Belzer; “Native Shrubs of Southern California,” Peter H. Raven; Dave Faires, Tim Paysen, Marcia Narog, U.S. Forest Service, Riverside Fire Laboratory; USDA Soil Conservation; state Department of Fish and Game.
