Post-fire outlook grim

LOS ANGELES – Southern California’s huge wildfire has turned nearly a quarter of the 1,000-square-mile Angeles National Forest into a moonscape of barren mountains looming above thousands of homes that now face the threat of flash floods and mudslides.

Experts are already evaluating the extent of risk to lives and property as well as the impacts of the wildfire on a forest ecosystem that in some areas may not have burned in at least a century.

The chief concern is the impact the 246-square-mile Station fire is having on the watershed. Countless canyons, ravines and gullies funnel watercourses toward communities at the forest’s edge.

The Los Angeles County Department of Public Works maintains a legendary flood-control system including basins – 30 to 40 in the area impacted by the fire – that intercept debris-laden flows from the canyons and trap mud and vegetation before the water continues on.

“Our concerns are that we will have a larger quantity of debris than normal being captured by our flood control system and, primarily, that individual property owners may be impacted by mudslides or mudflows to their properties,” said Mark Pestrella, public works deputy director.

In the forest, the consequences of the fire range from loss of wildlife and habitat to an indefinite closure of a vast area used for hiking, fishing, hunting, mountain biking and even commuting.

For the thousands of hikers, much of the forest may no longer resemble the descriptions in “Trails of the Angeles,” the bible for trekkers in the San Gabriels since the early 1970s.

“I think you have a hard time designing a more destructive fire from a hiker’s standpoint,” said Doug Christiansen, now co-author of the guide originated by John W. Robinson.

Christiansen said he and his wife hiked in the Angeles a few days before the fire.

“I feel like that was probably my last glimpse of the mountain range as I knew it. It’s going to be generations before it comes back,” he said.

Changes wrought by the fire are even more devastating for wildlife. There’s no doubt the massive fire killed off “thousands and thousands” of animals, mostly small mammals that could not escape the flames, said Pepperdine University biologist Lee Kats, who has investigated the impact of wildfires on wildlife.

“We have some animals that don’t have the best escape mechanism. While birds and larger animals can certainly flee, a lot of smaller ones can’t,” Kats said.

Scientists say it is too early to know what kind of long-term damage the Station fire wrought on the forest ecosystem. Chaparral generally is highly adapted to a fire-prone environment. But researchers are concerned that if chaparral burns too often, invasive weeds and flammable grasses could crowd out native shrubs, transforming the landscape.