How to maintain forest fire fuelbreaks
To combat the growing danger of wildfires raging through California’s national forests, federal officials are increasingly using fuelbreaks, a proactive measure designed to help fight fires before they even spark.
Yet the future of such fuelbreaks in the Sierras was called into question last month by U.S. District Judge Lawrence K. Karlton, who ruled that federal officials in the Lassen, Plumas and Tahoe national forests must address thorny maintenance issues if the preventive practice is to continue.
At issue in the lawsuit brought by the nonprofit Californians for Alternatives to Toxics (CAT), is the U.S. Forest Service’s lack of a plan for preventing the regrowth of vegetation in cleared areas.
Karlton agreed with CAT’s executive director, Patty Clary, that without maintenance, the network of quarter- to half-mile-wide fuelbreaks to be built along roads, ridgetops and meadows would soon become ineffective. Or worse, they could even increase the fire danger.
Yet maintaining those fuelbreaks can prove expensive, difficult and toxic.
Fuelbreaks are a centerpiece of the Quincy Library Group Forest Recovery Act’s Pilot Project, a compromise plan approved in 1998 that emerged from contentious forest management disputes between logging supporters and opponents in rural Northern California.
It directed the Forest Service to construct a series of defensible fuel profile zones (DFPZs), or fuelbreaks, that reduce fire potential, giving firefighters relatively safe areas from which to suppress wildfires.
Fuelbreaks differ from firelines and firebreaks, which are bare soil strips 2 to 30 feet wide hastily cut as a fire approaches. In contrast, fuelbreaks are created by thinning trees and brush before the fire starts.
The five-year project creates forest units 10,000 to 15,000 acres in size, surrounded by fuelbreaks, and will trim an anticipated 300,000 acres of vegetation, utilizing controlled burns and hand and machine clearing at a cost of $34.8 million.
According to court documents, the Forest Service neglected to mention herbicide use in the project’s Environmental Impact Statement (EIS). Instead, the Forest Service contended it needed a wait-and-see approach involving “site-specific project analysis.”
CAT attorney Dave Williams argued that DFPZ construction would result in increased growth of grasses and shrubs due to thinning that increases the amount of sunlight reaching the forest floor, therefore necessitating the use of herbicides.
Dr. Steven Radosevich, forest science professor at Oregon State University and author of a textbook on weed ecology, testified that to prevent vegetation regrowth, fuelbreaks would require maintenance in two to five years.
Maintenance methods include hand or machine clearing, prescribed burns and herbicides. But hand clearing is expensive, mechanical methods encourage regrowth by disturbing the soil, and prescribed burns are expensive, potentially risky and are usually coupled with an herbicide application.
The Forest Service ranks herbicides as the most cost-effective method of maintaining fuelbreaks. Yet Karlton noted the project’s EIS ignored adverse cumulative impacts to “microorganisms, threatened and endangered species, soils, humans, other mammalian species and aquatic populations.”
“They need to consider what’s going to happen when they remove the [forest] canopy,” said Williams. “A large amount of herbicides will have to be used.”
Glyphosate and triclopyr, two of the herbicides most commonly used, are found in both surface and ground water after application.
“It’s not that [these] chemicals are highly controversial poisons, but they do get into the water,” said John Buckley of the Central Sierra Environmental Resource Center.
Dan Zimmerman, an environmental investigator currently under contract with CAT, said, “Herbicides are fast and quick, but unfortunately [are] the most degrading and environmentally unsound [option]. The Forest Service always says that they don’t have enough money and have to use the cheapest alternative.”
Karlton wrote in his decision: “An agency must candidly disclose … risks posed by its proposed action … before the decision to proceed is made. Without maintenance the DFPZs will cease to be effective fuelbreaks within the life of the pilot project. The environmental impact of that maintenance must be considered now.”
As part of Karlton’s order, the Forest Service will address the issue of maintenance in a supplemental EIS due out in October. Clary lamented that DFPZ construction will continue while the supplemental EIR is prepared: “The Forest Service is radically altering vegetation … without knowing what the ultimate result is going to be.”
“If herbicides become the primary maintenance tool for this network of fuelbreaks … thousands of acres would be sprayed every year,” Zimmerman said, “[placing] the Sierra in the same league as the Central Valley for the amount of herbicides used.”
Project spokeswoman Merri Carol Murray said that the Forest Service has typically used prescribed burning as a maintenance method: “The supplemental EIS may analyze herbicide, brush crushing, fire, rototilling … goats, cattle, sheep—there’s all kinds of ways to manage vegetation, and herbicide is just one tool.”
Even within the fire management community, fuelbreaks have been debated for decades as interest in them has ebbed and flowed.
The California Department of Forestry’s Web site admits that fuelbreaks “have shown mixed levels of success” and “require ongoing maintenance.”
Dr. Timothy Ingalsbee, director of the Western Fire Ecology Center, writes: “Fuelbreaks have been tried before in the past with little success. The main factor accounting for the poor performance of fuelbreaks was the lack of brush maintenance. Soon after the timber was cut, these elaborate fuelbreak networks converted to brush fields of manzanita and other chaparral—a much more flammable, difficult and dangerous fuel type to cut fireline through than the original forest cover.”
Yet there are some emerging alternatives to traditional fuelbreak maintenance.
The city of San Francisco was so pleased with the performance of herds of goats in clearing land around the airport last year, it has contracted out additional projects to Orinda-based Goats R Us.
“CATs has seen excellent return on using goats," Clary said. "The Forest Service didn’t look at goats because they didn’t look at maintenance."