Early Thursday morning beneath an overcast sky, dozens of fire officials tramped across the northeast corner of Malibu Creek State Park to try to turn back the clock.
Their long-term mission, a park ecologist said, was to eradicate foreign plants, some of them introduced to the area centuries ago by Europeans. But for the roughly 154 sweating park officials and firefighters gathered to undo history, the clumps of milk thistle and mustard cluttering the landscape presented a more immediate challenge: It was time to burn.
"I want all this stuff down," Suzanne Goode, the ecologist supervising the burn, told a park ranger carrying a flaming fuel torch. The ranger obliged, spreading burning fuel on weeds that stretched to the edge of Las Virgenes Road.
Checking the wind, temperature and relative humidity every 15 minutes, the officials planned to methodically set 80 acres aflame on the western side of the road, between Lost Hills Road and Mulholland Highway. The fire followed a strict "prescription" that established the exact parameters of the blaze.
"When we talk about a prescribed fire, it's just like a doctor writing a prescription for medicine," said Russ Guiney, the local district superintendent for state parks.
For the third consecutive year, Goode had ordered the same cure for the invading weeds in this area--fire. Her colleague Frank Padilla Jr., a fire management specialist, wrote the prescription and led the burn with the help of the Los Angeles County Fire Department.
Not every fire, of course, is so rigorously controlled, with special paths cut into the ground and carefully watered, hemming in the burn area long before the first spark is ignited. That's why the law requires property owners to clear brush within 200 feet of their homes in the Santa Monica Mountains.
Less scrub and fewer trees mean less fuel for a raging fire. Goode said the dreaded thistle seeds stay alive in the soil for 10 years, so one fire is not enough to kill them. A single blaze, in fact, can make things worse.
"When you burn, you stimulate the seeds to germinate, because burning adds nutrients that act as fertilizer," Goode said. "So people say, 'Oh, you have more thistle than ever.' "
This year, the weeds are also more prolific than usual because of abundant winter rain.