Debate Flares Over Reseeding of Burn Areas : Conservation: Park agencies oppose use of ryegrass. They say it retards native plants.

Reseeding efforts in the Santa Monica Mountains after two firestorms that denuded more than 50,000 acres have rekindled a longstanding debate over introduction of non-native plants to the Santa Monica National Recreation Area.

Park agencies, backed by conservation groups, have strongly opposed the conventional strategy of reseeding with ryegrass to prevent erosion or mudslides, contending that ryegrass retards the growth of native plants and provides little or no erosion control.

State and county forestry officials say they will try to steer clear of parklands in the aerial reseeding, which could begin next week. But they said they are likely to use some ryegrass on nearby public and private lands because of the high cost and limited stocks of native seeds.

All available native seeds may go to Orange County, where the Laguna wildfire consumed about 10,000 acres of habitat of the California gnatcatcher, a tiny songbird that is a threatened species, state forestry officials said.

Despite environmental concerns in the Santa Monicas, “we’re not dealing with the focus on endangered species quite like Laguna,” said David Neff, regional resource program manager for the California Department of Forestry and Fire Protection.

Park officials and environmentalists have long been concerned with the deliberate introduction of non-native plants into the national recreation area, a 150,000-acre patchwork of public parks and private lands extending from Griffith Park in Los Angeles to Point Mugu State Park in Ventura County.

They say the introduced species crowd out indigenous plants that nurture the wide variety of animals and birds that inhabit the Santa Monicas.

The National Park Service, which administers the recreation area, has urged homeowners to use native plants in landscaping.

Park officials said they will selectively install berms and will plant native grasses to deal with the worst problems on more than 22,000 acres of burned parkland, but they will mainly let nature take its course, relying on fire-adapted mountain vegetation that sprouts quickly after fires.

Traditionally, ryegrass seed has been used after fires for erosion control because it is cheap and takes root quickly.

But park officials and conservationists say ryegrass’s performance is spotty at best.

“It’s more placebo and more reassuring . . . than it is an erosion-control device,” said Peter Ireland, executive director of the Mountains Restoration Trust.

Critics point to recent research underwritten by the state Department of Forestry itself. As part of a continuing $300,000 study, researchers planted ryegrass seed in 1988 and 1990 on three fire-scorched mountain sites in Southern California, including one in the Topanga Canyon area.

Preliminary results showed the ryegrass had no significant effect on erosion but retarded the growth of native plants, said Jan L. Beyers, a plant ecologist with the U.S. Forest Service and member of the research team.

Scott Franklin, a former Los Angeles County Fire Department captain who helped with the study, said it showed that “ryegrass seeding is strictly cosmetic and . . . may give people a false sense of security.”

But Neff of the forestry department stressed that the study is incomplete and said decades of experience with ryegrass have yielded mixed results.

Neff said Wednesday that in deference to park officials’ wishes, state forestry officials will not reseed the western part of the mountains in Ventura County, except for about 2,600 acres near Lake Sherwood, where ryegrass will be used.

Paul Rippens, chief of the Forestry Division of the Los Angeles County Fire Department, which will oversee reseeding efforts in Los Angeles County, defended ryegrass but said as much native seed as possible will be used on the eastern side of the mountains.

Reseeding of about 4,000 burned acres near Altadena began Monday with a mix of ryegrass, native grasses and California poppy seed, Rippens said.