Los Angeles leaders looking at 820 acres of charred ground in Griffith Park are eager to come up with a recovery plan, in part to allay neighboring residents' fears of wet season mudslides. But scientists say one of the best restoration strategies is to wait. KPCC's Molly Peterson reports.
Molly Peterson: Parts of the Griffith Park ridge he's looking at are charred grey and white. But Dan Cooper, a conservation biologist, sees signs of life through his binoculars. Coyotes, he says, are back up on the hillside. And the wildfire didn't burn every hillside clean.
Dan Cooper: I'm just looking at the laurel sumac: Half of it's burned but half of it's still green. Right below the soil there are seeds, and these seeds are perfectly fertile, and they're going to sprout in a matter of weeks, and even without rain we could see some grasses growing, and certainly the shrubs will sprout even without rain.
Peterson: Those fire-following flowers and shrubs are a part of the way chaparral land, found throughout the park, has adapted over centuries to fire; ecologists know them well. But Cooper says much of what people know about the trees, plants, and animals living in Griffith Park is anecdotal. In the absence of federally protected species, the city wasn't required to make a full and complete list. That's why some neighborhood groups hired him to take a census before the blaze started.
Cooper: There are some species that I had no idea I would find. I wasn't sure how many quail I would find, but quail are everywhere and in fact on the west side of the park, near the Hollywood reservoir, there were flocks of over 50 individual quail just a few weeks ago.
Peterson: Now the fire in Griffith Park is last week's news, and some attractions are open. But Mike Shull, a planner with the city's Department of Recreation and Parks, says recovery is just beginning. With it comes a new opportunity for figuring out what's going on with the plant, animal, and bird life there.
Shull heads the task force the city's still putting together. He says the group hasn't yet decided how to proceed with healing the park.
Mike Shull: There's so many different ways to go about it, we just don't know which one is the best to use at this point. Whatever we do, we are going to take, we have got to make sure that we keep the ecosystem intact as much as possible. We gotta let nature do its thing.
Peterson: That means, in part, learning more about what it's done so far. Shull says it also means taking note of public safety, including risks to neighboring houses. The task force will do that with a more detailed flyover survey, one that will give the parks department three-dimensional images of the hillsides.
Shull: We have a number of canyons in Griffith Park that feed down into our property or residential or commercial areas, and so our guiding principle is public safety. So we want to make sure that's what is addressed first.
Peterson: Even before the fire was out, city and state officials announced a $50 million recovery plan. Park rangers were already talking about replanting and reseeding hillsides to fight against the possibility of mudslides during heavy rains.
Jan Beyers, a plant ecologist with the U.S. Forest Service, has researched how well replanting and reseeding works. In the 1990s, she and other Forest Service researchers measured runoff on hillsides covered with annual sprouting rye grass, and compared it to bare spots.
Jan Beyers: One of the problems with seeding as an erosion treatment is that the same rain that is necessary to cause the seeds to germinate and the grass to grow is also going to produce a lot of sediment movement before there is plant cover to slow it down. So even in the best of conditions, putting out seeds of things is not going to prevent a big slug of erosion from occurring after a fire.
Peterson: Beyers points out that there's only so much real estate for plants to push up through, and only so much sun and water to nurture them. More seeds mean more competition for the native species already present.
Beyers: There are limited resources in terms of water and soil resources in any natural ecosystem, so if you add seed it's usually going to grow at the expense of what's already there.
Peterson: But in an urban park, with a mix of native and non-native species, it's hard to know what is there. In areas like Dante's Peak, residents have changed the landscape with decades of their own planting.
City Councilman Tom LaBonge says he's concerned for Los Feliz homes, so he hasn't ruled out re-seeding as an erosion control measure.
Biologist Dan Cooper says reseeding isn't always a mistake.
Cooper: You just have to be careful, because you have to live with what you seed.
Peterson: Along the L.A. River, between the Los Feliz municipal golf course and Griffith Park, Cooper points out a hostile invader, one likely introduced through ill conceived planting.
Cooper: This is fountain grass, or freeway grass, and it forms this matt. And let's say you're a nice native California poppy and you want to get to the sun. You can't get through that thing. And so when you have a matt of fountain grass, it's like an ice plant, it takes over everything.
Peterson: Besides reseeding only with native species, botanists and ecologists say the city can also consider natural surface coverings, like rice straw mulch and hay bales, to reduce the hillside erosion threat when it rains. Whichever strategy park managers choose, they're under pressure to get it going soon. Mike Shull from the Los Angeles Department of Recreation and Parks says he wants protection in place before the rainy season starts in November.
Shull: It's extremely aggressive, but we cannot take the chance that the health and well being of the communities around there are going to be impacted.
Peterson: Shull says he expects the recovery task force to begin meeting within the month.