The Southland Firestorms: The Battle Goes On : Wildfires Blacken One-Third of National Recreation Area : Environment: The ecosystem may not be able to stand the increasing frequency of fire, one expert warns.

The wildfires of the past week have torched more than one-third of the public parklands in the Santa Monica Mountains National Recreation Area, turning some of its most popular trails and activity sites into ravaged moonscapes.

More than 22,000 of an estimated 66,000 parkland acres were charred by last week’s Thousand Oaks blaze and the Calabasas/Malibu fire that at dusk Wednesday was advancing into Topanga State Park.

Unlike scorched houses, chaparral-covered lands recover quickly, demonstrating with brilliant wildflowers their dependence on fire.

However, while fire is a natural feature of the ecosystem, “increasing levels of development and . . . crazy people who like to commit arson” may be bringing “more frequent fires than the ecosystem can really stand,” warned Suzanne Goode, an associate resource ecologist with the state parks department.

She said that could prompt a “conversion to a different type of plant community that is not capable of supporting” the diversity of species that now inhabit the mountains.

The national recreation area is a patchwork of private tracts and parklands of several agencies, including the National Park Service, the California Department of Parks and Recreation and the Santa Monica Mountains Conservancy.

Near its flash point outside Calabasas, the fire roared through the conservancy’s Red Rock Canyon Park on Tuesday, gathering steam for its march to the sea. Three conservancy employees, including agency head Joe Edmiston, manned hoses to save three buildings, although a minor structure was damaged.

But as it barreled through the conservancy’s 310-acre Stunt Ranch, the fire torched a nature center, a caretaker’s residence and two homesteads, built in 1917 and 1889.

It also charred the 750-acre Cold Creek Canyon Preserve, managed by the Mountains Restoration Trust, said the trust’s executive director, Peter Ireland.

Also burned were conservancy and Park Service lands in Las Flores Canyon, Park Service and state parklands along the Backbone Trail in Hondo Canyon and on Saddle Peak, and the southeastern edge of Malibu Creek State Park.

The destruction added to the toll from last week’s Thousand Oaks blaze, which charred most of 14,980-acre Point Mugu State Park and National Park Service lands in the Deer Creek Canyon, Rancho Sierra Vista/Satwiwa and Circle X Ranch areas.

A large but unknown number of wild animals have been displaced or killed, and the fires have raised the threat of erosion, floods and mudslides with the coming of winter rains.

But park officials for the most part expressed more concern for ruined homeowners than for their wasted parklands. For one thing, they say, the visual scars won’t linger long on the brushy hillsides as they would in a deep forest park. For another, fire is essential to the healthy functioning of the chaparral environment.

“We’re obviously quite concerned about all the people around us,” said Neil Braunstein, a district planner with the state Department of Parks and Recreation. “Strictly speaking, from our point of view, the fire’s not necessarily a bad thing.”

Brush fires recycle nutrients to the soil and clear thick tangles of aging brush that obstruct animal movement and prevent the growth of younger plants that provide more nourishment for wildlife.

New plants sprout almost overnight, and the winter rains often bring a bumper crop of spring wildflowers.

Park advocates say the destruction vindicates the decision to preserve open space that was born to burn.

“You might ponder all the future costs we saved the taxpayers and policyholders of this state by working to have (parklands) acquired . . . before they became loaded up with houses,” says the latest newsletter of the Sierra Club’s Santa Monica Mountains Task Force.

“We also need to realize that allowing people to build houses in chaparral is like allowing people to build homes in oil refineries or next to dynamite factories.”