Fighting fire with fire

Can prescribed burns lower the fire danger in Bidwell Park?

Chico State professor Don Hankins, admiring this valley oak in Lower Bidwell Park, advocates the use of controlled burns to manage the health of certain natural habitats.

Chico State professor Don Hankins, admiring this valley oak in Lower Bidwell Park, advocates the use of controlled burns to manage the health of certain natural habitats.

Photo By Karen Laslo

Park fire:
The city of Chico Park Division scheduled a controlled burn for this week at the grassland area north of Upper Park Road in Middle Bidwell Park. The Chico Fire Department will conduct the burn, which may continue into next week.
About the author:
Kim Weir is editor and publisher of Up the Road (, a Chico-based online publication dedicated to environment, economy and equity. This article, a collaboration between the CN&R and Up the Road, is the first in an occasional series about fire in the California landscape.

Here’s a scenario Bidwell Park lovers wouldn’t want to imagine: It’s a crackling fall day, dry as days-old toast. After no rain for many moons there’s finally a brisk nip to the air. Change is coming.

A north wind kicks up, gusting down dusty paths. Suddenly wildfire explodes across Lower Park—one spark fanned into a firestorm that ignites dry grass, roars through thickets of shrubs and young trees and then wicks up wild grape vines to torch majestic old oaks and sycamores. Red-hot ashes rain down on the wood roofs of million-dollar houses that flank the park, setting those neighborhoods ablaze.

It’s almost unimaginable, an instant inferno in the verdant heart of Chico. Yet such a wildfire is quite possible here, given the right conditions—and given the park’s “fuel load,” in firefighter lingo. Imagining this disaster is at least a step toward preventing it.

Don Hankins, pyrogeo-grapher and assistant professor at Chico State as well as field director at the Big Chico Creek Ecological Reserve (BCCER), is well versed in fire-safety practices and the ecological uses of fire. So far he has used controlled burns only in the upper reaches of the watershed, but he is comfortable with using fire in Lower Park, too.

“It’s one of the most inexpensive tools we have to manage vegetation,” he said. “But there has to be a willing, well-informed public to support it. And sometimes public education takes a while.”

The native Concow people who inhabited this area regularly used fire for particular purposes, according to Hankins, clearing paths to favorite waterholes, establishing basketry plants and encouraging bunch grasses and abundant acorn crops for wildlife.

Native people managing plant and animal habitat with fire didn’t have to contend with air-quality concerns and no-burn days, however.

California native plant communities are adapted to fire, Hankins pointed out, certainly oak-woodland areas such as Bidwell Park. Some species require fire before dormant seeds will germinate and sprout. Because of these adaptations fire helps native plants compete against otherwise dominant interlopers.

One example of this: The perennial bunch grasses once common here; introduced annual grasses have all but choked them out here and throughout the valley.

Almost as dramatic is the case of valley oaks, which in Lower Bidwell Park aren’t successfully reproducing, which means adolescent and middle-age trees aren’t surviving to eventually replace mature oaks. Regular burning would thin out seedlings and young trees—including competitors such as the park’s non-native black walnuts—leaving adequate room for developing oaks plus plenty of fertilizing ash.

Fire even diminishes parasitic damage produced by oak gall wasps, which create apple-shaped outgrowths or galls that sap essential energy from young trees, Hankins said. For reasons not fully understood, regular burning also practically eliminates mistletoe as a tree parasite.

Using fire for habitat management is as much art as science, said Jeff Mott, director of the BCCER.

Fire helps control damage from insects, including these apple-shaped growths resulting from exposure to gall wasps.

Photo By Karen Laslo

“It’s taken us a long time to figure out how to use fire—when to use it, and where—and to make it work,” he said.

But the preserve is now having notable success, such as expanding native bunch grass habitat and producing “phenomenal” acorn crops, which the wildlife appreciate.

Frequency of fire is crucial, said both Mott and Hankins. Frequent burns are needed to eliminate annual grasses, for example. Timing is also critical. Fall burns—right after the first rain, when vegetation is dry but humidity is high—are ideal for most purposes.

But Hankins suspects people will be resistant to lighting intentional fires in Lower Park as an ongoing practice.

“At what point would people get fed up with doing this continuously?” Hankins asked. “Public education—that is the key. The community would need to support this.”

Dan Efseaff, the city’s park and natural-resources manager, said there’s been positive feedback for prescribed park burns. So far, about 150 acres have been burned, but only in Upper Park and Middle Park.

Volunteer work to remove non-native vegetation in Lower Park has reduced fire danger, he said. But the potential for controlled burns is limited because that stretch of parkland runs perpendicular to prevailing winds, which can limit the “fetch” or unhampered movement of fire. Using fire to help establish shaded firebreaks throughout Lower Park is nonetheless a goal.

“I’m hoping in the next few years to start using prescribed fire in Lower Park,” Efseaff said, starting in the old walnut orchard along Vallombrosa.

Yet controlled burns in Lower Park can’t be the entire answer, even if public opinion comes to support them, said Jim Bishop, a former fire-behavior analyst for CalFire. Today, there are far different fuels, ignition frequency and ecosystem features than in the past, he pointed out.

“It is too simplistic to think that introducing a program of late-season, low-intensity fire will somehow restore the ecosystem to its natural state and reduce the overall ‘fire danger,’ ” he said. “It will take a combination of managed fire, purposeful plant introductions, protecting vulnerable plants and some experimentation to find the optimal approach.”

Susan Mason is on the invasive-plant front lines in Bidwell Park, coordinating Friends of Bidwell Park volunteers who regularly remove unwanted vegetation. She estimates it took at least 2,000 hours to remove the non-native blackberries for the Sycamore Restoration Project, a very small patch of ground where aggressive vines were stifling young sycamore trees.

“One problem is, the city of Chico is short of money and so short-handed they can’t even haul [vegetation] for me,” she said. “They barely have time for the mow-blow and cleaning bathrooms, the things most people care most about.”

The first thing that needs to happen, she said, is raising awareness—while also raising money to properly care for the park.

“People concerned about fire danger should get involved. We need an endowment fund, which could simply be a fund set up with the North Valley Community Foundation, so people who want to give money to support Bidwell Park can easily make a contribution.

“Get involved,” she urged. “Do some fundraising for the park, talk to your friends. And if you live near the park and have a wood roof—I’d call a roofer right now and replace it.”