Five years ago, an arsonist is believed to have sparked what would become the largest wildfire ever recorded in Los Angeles County. Today, despite years of drought, the Angeles National Forest is recovering. But that may not happen the next time a fire rips through the San Gabriel Mountains.
Richard Minnich was in the San Gabriel Mountains recently, examining the recovery progress of the trees and shrubs. Five years prior, the Station Fire, which raged for seven weeks, devastated a quarter of the Angeles National Forest.
Minnich, a fire ecologist and a professor at the University of California in Riverside, was encouraged by what he was seeing during the visit. Regrowth was occurring in a lot of the chaparral, including a chamise plant that had clearly burned in the fire.
"You can see the dead stems [are] burned, and you can see young, green sprouts coming out of the same root system," Minnich said. "This one's pretty green, and even though they're in extreme drought, it doesn't have a high water demand, because it doesn't have a lot of neighbors with a high water demand."
Minnich explained that the current drought has had little negative impact on the regrowing plants, because the fire lessened the plant canopy, which in turn increased the amount of available water.
"Plants in general are water faucets. Plants are always uptaking water and sending it from the roots through their stems and out their leaves and out of the leaves through their stomata,” Minnich said. "The plants do better because of the fire, because there's more water available in the ground."
Many of those plants are serotinous, meaning they reproduce by dropping seeds only after they’ve burned and died.
A destructive fire
Perhaps it shouldn't be surprising that plants that evolved to thrive in a fire-prone environment would be able to recover after a wildfire. But the Station Fire was an abnormally large and intense conflagration.
The fire is believed to have been sparked by an arsonist on Aug. 26, 2009. By the time it was finally contained in mid-October, the fire had destroyed scores of houses, charred more than 160,000 acres and caused the deaths of two firefighters.
The roughly 250 square miles that burned made the Station Fire the largest wildfire in Los Angeles County’s recorded history.
Minnich said that he believes the immensity of the wildfire was due to an overabundance of fuel, which he attributes to excessive fire suppression. The somewhat controversial idea is that putting out small fires leaves overgrown, fuel-heavy forests that explode when big fires come through.
He refers to the process as "fire selection."
"You can suppress all you want, you're never going to get rid of the process," Minnich said. "But now we're confining that process to extreme conditions that are making our fires extremely intense."
Minnich said he would prefer that the Forest Service allow smaller fires to burn during summer months, when winds would keep the flames away from the city. He says burning 2 percent of forests each year would keep fuel in check.
”Every acre you save is an acre that will bite you later," Minnich said. "It's an old story: Pay now or pay later, and they're always taking the pay later option.”
He said proof of the concept can be seen in the widespread loss of big cone Douglas fir trees from the mountains.
"Probably the best evidence that suppression has truly changed the fire pattern and made it more extreme is the mortality and disappearance of big cone Douglas fir," Minnich said.
The big cone Douglas fir tree differs from many other plants in the area in that it evolved to survive wildfires, losing its lower branches but maintaining a living crown.
Unlike serotinous plants, the seeds of big cone Douglas firs die if the tree completely burns. That’s what happened in the Station Fire, which was abnormally large and abnormally intense. Once abundant, the tree is largely gone from the burn area.
Minnich said that about 40 percent of the trees have disappeared from Southern California since the late 1930s.
"This species is just getting hammered," he said.
Other researchers believe climate change could further exacerbate the losses.
"With drier conditions and hotter conditions, a fire might be more likely to grow in size. That will affect how the forest recovers, because it can affect how far away a seed source is," said Sharon Hood, a former fire ecologist for the Forest Service.
Hood, who is scheduled to receive her doctoral degree from the University of Montana in December, studies fire and forest dynamics. She said a two-degree Celsius increase in global temperatures is seen as a benchmark that would cause consistent alterations in trees' survival patterns.
"They would either have to move north or higher up the mountain," Hood said. "Most of the time, trees can't move that fast for the rate of temperature increase that we're seeing."
Hood says there’s evidence that these changes can already be seen in Arizona and New Mexico, where fires have caused large forest die backs.
Some people are working to keep that from happening in the Angeles National Forest. Volunteers and workers with national and local organizations have planted roughly a million saplings there during the five years since the Station Fire.
“It's a part of the puzzle. It's a small piece, but it's a necessary piece, so you want to bring back that component and make sure it's not lost for good," said Edward Belden, Southern California program associate with the National Forest Foundation.
The nonprofit organization spreads awareness of forests and provides opportunities for people to volunteer. In addition to planting, Belden said workers have cleared invasive species from more than 200 stream miles in the forest.
"I think we're on a good trajectory because of the amount of work that people have put in to making sure that it's a successful restoration project," Belden said.