The deadliest fire in state history destroyed the town of Paradise and blanketed the capitol in smoke for three weeks. The governor and state legislators responded with several bills aimed at slowing these natural disasters, speeding up the response and dedicating more funds to the fight.

The steep cost of fighting these fires has raised new interests in prevention strategies—including forest thinning and other forms of vegetation management—and has renewed old conflicts over the use of herbicides, one of the most cost-effective tools in the kit.

Also worried about the fires to come are researchers. The challenge is steep: California’s Forest Carbon Plan calls on increasing the amount of vegetation treated to at least 35,000 acres per year, beginning next year. Another study commissioned by the state projects the average amount of area burned by wildfires to increase by 77 percent by the end of the century.

“The crisis of our time is wildfires in California,” said Sen. Bill Dodd, D-Napa, in an interview with Agri-Pulse. “That has really become the majority of my legislative life since the North Bay fires.”

Dodd now has three wildfire bills up for vote. Among those is an ordinance requiring local governments to enforce defensible spaces around structures, which would require landowners to be more diligent with managing vegetation.

The California legislature has also appropriated $200 million for fighting fires to the Department of Forestry and Fire Protection (Cal Fire) from the Greenhouse Gas Reduction Fund, doubling the amount the department received last year. In the first year of the fund, Cal Fire received $42 million. Per Sen. Dodd’s SB 901 bill last fall to improve forest health, Cal Fire is also receiving $1 billion over the next five years from the fund. The governor’s proposed budget would also provide Cal Fire with $254 million for resource management for a number of activities, which includes vegetation management. 

bill dodd

Sen. Bill Dodd, D-Napa

Last year, Cal Fire spent nearly $1 billion fighting wildfires, well above its budget at the time and more than 75 percent above its budget five years earlier. The bulk of that funding has predominantly gone to fire suppression over prevention, according to Lawrence McQuillan of the non-partisan Independent Institute’s Center on Entrepreneurial Innovation. Cal Fire is asking for new tanker aircraft this year and more boots on the ground when fires break out and in deployment throughout the state during critical fire conditions.

Much has been debated about forest thinning and the associated costs, while the role pesticides play in prevention has been diminishing, despite the potential cost saved if those chemicals are used more strategically.

“Everything is reactionary and not prevention,” said Travis Bean, a cooperative extension weed specialist at UC Riverside, who researches the wildfire threat from plants.

In grasslands throughout the state, ecosystems have been entirely replaced by invasive species that are fire prone, like mustard grasses and medusa head. As these plants promote more fire, they also move into the recent burn areas and promulgate their species. They grow along roadsides, presenting a gateway for fire to reach the pockets of native species. On steep slopes after burns, invasive plants with shallow roots take over, leading to slides when the first rains fall. Without that soil, it is impossible for the native plants to return.

The most cost-effective way to tackle a problem on such a massive scale is through a selective broad-spectrum herbicide. Yet no statewide program exists for this and no agencies track the extent of herbicide use in fire prevention, as the Department of Pesticide Regulation does for agriculture.

The state funding that does go to prevention tends to be for educating the public on “fire wise communities,” which involves encouraging private landowners and local agencies to create safe spaces of 100 yards from buildings, said Bean.

bulldozer digging firebreak

More often, vegetation management is in response to an active fire and involves bull dozing fire lines across landscapes to create dead spaces. Bean said applying herbicides ahead of time to create firebreaks would be “orders of magnitude less expensive” and less damaging to the ecosystem. Ripping up vegetation leaves a lasting scar on the landscape for decades, he said.

“And it would also be a pathway to further invasion by invasive species that are one of the leading causes of these fires,” he said.

Ignitions nearly always start along roadsides and utility corridors, whether from a car, a cigarette or an electrical wire. This accessibility allows for more targeted herbicide use as well. Larger swaths can be sprayed from a vehicle or more selectively from a backpack sprayer to protect key species or scenic views. Scaling up, costs go down as more acreage is treated with herbicide, while costs rise as more labor-intensive strategies are deployed.

“If you’re going to go big, you might as well go home,” said Bean. “The problem is so widespread if we’re tackling it piecemeal.”

Despite the demand, it is hard for a company to make a profit from producing an herbicide specifically targeting these invasive species, given the decades long process for research and development.

“We just have a super limited menu of herbicides, compared to agriculture,” Bean said.

This leaves land managers with glyphosate, the most effective tool for selectively killing these grasses without impacting livestock or wildlife. With other herbicides, the potential for collateral damage is higher as the herbicide is more mobile and can move downhill or through soil easily. Bean cautions that glyphosate is not the solution for all weed problems and that every tool for preventing fires should also be considered.

Yet he is finding that local jurisdictions are increasingly removing it from the menu, including irrigation districts, where glyphosate would be the most effective against riparian plants.

“When you talk about nonchemical, you’re really limiting yourself to small areas at extreme costs,” he said, adding that machinery can’t easily reach steep areas either.

In a recent study, public health researchers have also questioned the health risks of pesticides when they burn and contribute to the air contamination during these fires.

A steep cost for alternatives

Cal Fire does not use herbicides, according to a spokesperson. Vegetation management is preformed through mechanical thinning. The 31 million acres that Cal Fire overseas is primarily private property and the responsibility of the landowners.

Cal Fire and federal agencies do fund local Fire Safe Councils, which provide grants to local community groups for prevention efforts like vegetation management. These projects usually involve mastication, in which large excavators with a grinding head chew up entire trees into wood chips. The approach requires routine maintenance, since brush can grow back within a year.

“The cheapest, quickest, most efficient way to do it is to come in and use an herbicide to knock all of that regrowth back,” said Scott Oneto, a UC farm advisor for counties along the foothills of the Central Sierra Nevada.

He said the third management tool is contract grazers. In a flip from tradition, ranchers are paid to graze their livestock in these areas. Brad Fowler, who runs The Goat Works, said in the last five years his business has shifted from weed abatement to mostly fire hazard reduction. And business is doing well.

“Private land managers and a fair number of public agencies, municipalities and utilities are using us fairly extensively,” he said.

Fowler described it as a logistics business that involves animals. He transports a whole ranch infrastructure – fencing, water, shelter, corrals – to every site. His goats take care of “anything from ground level to six feet up,” while thicker brush and trees require mechanical tools. The goats can consume much of the vegetation, trample more down and work in steep areas that are treacherous for humans and machines.

Regardless of the options for tools, Scott Oneto acknowledged his challenge is largely with private landowners.

“The majority don’t do a whole lot of vegetation management in general,” he said. “A lot of people have the mindset that nature will take care of itself.”

This has led to such a fuel buildup across the foothills that often the only solution left is mastication. Herbicides can play a secondary role with tackling regrowth later, he said.

The grasslands pose a threat of a different sort. California’s wet winter has led to a lot of excitement for growers. For Travis Bean, however, the greenery is an omen:

“As a weed scientist, when I see this, I say: ‘A big, big fire season is coming.’”