The Fire that Never Starts

CALIFORNIA, UNITED STATES

03.07.2026

Story by Andrew Avitt 

USDA Forest Service   

When 95% of wildfires are started by humans — especially in a part of the country like Southern California with 25 million people — stopping wildfires before they start is a lofty goal.

But for Nicole Molinari, an ecologist for the Forest Service, a recent mapping effort contains a compelling insight — nearly two thirds of human-caused fires occur along roadsides in the area.

The compiled dataset, https://www.arcgis.com/apps/dashboards/f7536596ef1a47c4966d62a8bc98d90e, maps 26 years of fire starts across the Angeles, San Bernardino, Los Padres, and Cleveland national forests, including 850 miles of national forest roads.

Equipped with this data, and with the recent memory of the two fires that devastated parts of Los Angeles last year, federal, state and local land managers are developing strategies to reduce ignitions in this highly flammable, densely populated region.

Shrubland, California and Fuel Breaks

“Chaparral ecosystems have evolved with fire in a different way than forests. Often times in southern California, where fire is so frequent, the best fire to have is the fire that never starts,” said Molinari.

Molinari grew up in southern California nestled near the foothills of the Cleveland National Forest and studied grass invasion and the effects of fires on ecosystems at University of California, Santa Barbara. She has worked for the Forest Service for 10 years, bringing science to the decision-making table on land management projects from Big Sur to the Mexico border.

“The classic wildfire mitigation, or fuels treatment, in Southern California is a fuel break,” said Molinari. “If you look up on many of our ridgelines, we have either a maintained fuel break or a fuel break created by a bulldozer during a fire.

“These are features we rely on in Southern California, but we also understand that they're not always effective.” Fuel breaks lose effectiveness during extreme weather conditions, like the strong Santa Ana wind events that drove the Eaton and Palisades Fires last year.

“During extreme conditions like that, we don't expect fire to go out when it hits the fuel break. We also don’t expect firefighters to be staged up on those ridgelines. It’s just not safe,” said Molinari.

That’s why reducing the ignitions and stopping the fires before they start is a focal point for fire departments and public lands managers.

The New Frontier of Grassy Roadsides

Vehicles dragging chains, people throwing cigarettes, or vehicles parking in tall grass are all common causes of roadside starts. The Forest Service as well as municipal fire departments have known this for years, leading to education prevention campaigns like One Less Spark, One Less Wildfire.

“One option is to educate, make people aware of the risk,” said Molinari. “Another option is managing roadside areas, by replacing non-native grassy fuel that is dry and easily ignitable through much of the fire season with hardscaping like decomposed granite, though this option may be prohibitively expensive or require continual maintenance.”

But there may be a more innovative, simpler, cheaper and more ecological way to make roadsides less likely to catch fire.

“If you look at the roadside environment, they’re frequently dominated by invasive annual grasses from the Mediterranean basin. They grow when there’s rain and they’re nice and green. And then in the springtime they fully dry out and die,” said Molinari.

Forest Service research has shown that areas with non-native annual grasses are six times more likely to ignite than in areas with native vegetation. Another strategy — reduce these flashy, non-native grasses and replace them with less ignitable native vegetation.

“Guided by the data, we don’t have to look at every mile of road. We can see where the historical ignition hot spots are, and we can see where the more ignitable invasive species are most present and prioritize the work,” said Molinari.

To choose the right fire resilient species, the Forest Service is working with researchers at UC Santa Barbara to study the ignitability and flammability of these invasives compared with native species.

Robert Fitch, Grasses Guru

Along Forest Service Road 5N20 on the Los Padres National Forest, Robert Fitch exits his vehicle onto the shoulder. He quickly scans the buffet of grasses to the side of the road and gets to work, pulling a few and carefully bagging them for later use.

He remarks about how green everything looks, since the coast has been inundated with precipitation over the past few weeks. But he said to not be fooled by the greenness. In the summer the landscape will be dry, the grass just waiting to carry fire.

Fitch is a postdoctoral researcher at UC Santa Barbara, studying restoration ecology and fire science. With his new specimens, he returns to the laboratory to meticulously burn the plants in a controlled environment, film the fire, then analyze the specimen’s flammability.

This process of studying plant flammability is all part of Fitch and his colleagues’ research, to link the likelihood of ignition with different vegetation types and species — invasive annual grasses and native plants.

“We filmed the ignitions and measured various fire attributes. And what we found is that, in general, annual grasses that have invaded a lot of these locations along the roadside were the most ignitable.”

While non-native annual invasive plants grow quickly, seed, dry out and die, native perennial plants retain moisture into the summer and early fall and will green back up in the spring. They need to retain that moisture to survive.

When it comes to ignitability the amount of moisture in plant leaves and stems is a major influencing factor. The lower the moisture the more easily ignitable. Because of this Fitch and his fellow researchers collect vegetation multiple different times throughout the year from spring to October, to capture how moisture levels change over time.

There are also physical characteristics that make certain plants more or less ignitable, said Fitch. “Because grasses have these long thin leaves, it's very easy for them to catch fire and rapidly spread from one plant to another.”

In contrast, some native chaparral plants remain close to the ground, with spaces between the plants, so fire doesn’t carry as quickly. In these areas, it’s more common to see fires smolder and spare the plant.

Universities like UC Santa Barbara routinely work with the Forest Service across the country, to co-develop research questions and then tailor studies to better inform land management decisions.

For this particular project, the Forest Service knows roadsides account for the majority of human-caused ignitions. But the agency still lacks clarity on which species ignite most easily and which are more resistant.

“Our current project with the Forest Service on the Los Padres National Forest is examining how we can replace vegetation in locations across Southern California with less ignitable native California plants,” Fitch said.

This could help the Forest Service, city managers, and community planners reduce ignition risk in locations that have been historically ignition prone.

Throughout his research, Fitch has met with wildland firefighters, walking fuel breaks and roadsides, hearing their experiences, and reflecting on what he sees in the lab.

“There’s a lot of agreement. The consensus seems to be, if we can find more fire resilient and ignition resistant plants, it could make a real difference. This research and land management approach could apply to preventing wildfire starts in other shrubland ecosystems across the country.”

The Bigger Grass Picture Land managers like Molinari with the Forest Service and researchers like Fitch with UC Santa Barbara are just a few collaborators in the larger effort to reduce fire starts in Southern California.

Last September, federal, state and nonprofit partners came together to sign the Southern California Ignition Reduction Program charter focused on reducing wildfire starts along roads.

Leading this program is an executive committee that includes the Forest Service, Caltrans, CAL FIRE, and the California Department of Conservation — with advisory support from the National Forest Foundation, Blue Forest, and Conservation Investment Management. The California Wildfire and Landscape Resilience Task Force also joined the charter and celebrates this partnership as the type of regional strategy they’d like to see statewide.

These major partners, along with smaller municipalities and community groups, will share the work. This holistic approach to wildfire risk reduction will include ignition reduction along with building and maintaining fuel breaks, removing invasive plants/grasses, and restoring native ignition-resistant species.

For Molinari, partnerships like the Southern California Ignition Reduction Program create opportunities to make a difference at scale.

“From the Forest Service side, we don't really have the people and resources to do this work alone. But together, with partners big and small, we can help to limit those wildfires from starting.”

• Date Taken: 03.07.2026
• Date Posted: 03.09.2026 21:19
• Story ID: 559639
• Location: CALIFORNIA, US