May and June 2006



Creating Shaded Fuel Breaks

Shaded Fuel Break System Shields West Coast Forestland from Wildfire

By Amie Dunn

Western foresters are no strangers to wildfire. Each year, millions of acres are scorched by fire, destroying native plant and animal populations, treasured national parks and forests, homes and even entire communities.

Forest landowners face the challenge of protecting privately owned pine stands from fire while maximizing the total forested acres. One way to protect areas from fire and slow its movement is to create shaded fuel breaks within forestland property.

Shaded fuel breaks are one effective way to defend forests against wildfires in west.

A shaded fuel break is an area within a forestland that has been treated or managed to remove or decrease fuel loads. Heavy underbrush and fallen limbs are generally removed, leaving mature trees that are more fire resistant.

This creates a break in vegetation, which slows the speed of wildfire and provides firefighters with a safe zone. Creating shaded fuel breaks can decrease the number of fires and allow federal funds to shift from fighting fires to other critical projects. They also help protect communities located
within the fire danger zone.

The first step to creating a break is thinning pine stands and ensuring appropriate spacing between trees.

Fighting Fire by Removing Fuel

Pat Minogue, president of Allied Environmental and Forestry Consultants in Redding, Calif., helps develop shaded fuel breaks in western forests. According to Minogue, the concept of the shaded fuel break was invented in Quincy, Calif., a community of 1,800 people located in the forests of the Sierra bioregion.

“In many states, growing communities are getting closer to heavily forested areas,” he says. “There is no longer a significant amount of space between forestlands and communities, creating a higher risk of wildfire that could encroach on communities.”

A cooperative of foresters, environmental organizations, fire safe councils and timber companies came together in Quincy after the 1992 Cleveland fire, in the heart of the Sierras, burned nearly 20,000 acres and threatened their communities. The group now works to protect land in several east central California counties.

“The goal is to create a system of shaded fuel breaks that support the developing forestland, but decrease the fire potential and severity,” Minogue explains.

Logging, Piling and Pruning

Sierra Pacific Industries, one of the largest privately owned industrial timber companies in the western United States, has benefited from the work of Craig Ostergaard, a regeneration forester with the company who worked with Minogue to create shaded fuel breaks on Sierra Pacific forestland.

“To make a shaded fuel break, we leave a band of trees with a relatively open understory, and a canopy that provides enough shade to keep the understory from redeveloping,” Minogue says. “It shouldn't be bare underneath. Native grasses that burn cooler and quicker should be restored, allowing any fire to move through without damaging the forest stand.”

“We first log and thin the pine stands at the ridgelines to make sure the spacing of the trees is appropriate - depending on the species,” Ostergaard says. “Then, we do a tractor or excavator piling or a controlled burn to
remove understory brush. From there, we often bring in the California Department of Forestry and Fire Protection (CDFFP) and the U.S. Forest Service for final cleanup and pruning.”

Crews led by Jeff Holland of CTL Forest Management/Armstrong Logging use Rottne forwarders to remove pulp and saw logs from the fuel breaks. Needles and branches are left on the forest floor for fire fuels and removed with a prescribed burn. “In many cases, burning is easier and less expensive than piling the remaining brush,” Ostergaard says. “Plus, it returns nutrients back into the ground.”

The most intensive shaded fuel break work is done 300 to 600 feet from ridgelines because fires naturally slow there.

Added Benefits of Herbicides

Herbicide is later used at the preemergence or foliar stage of the understory growth to help control regrowth longer. “We've found that without any treatment beyond mechanical removal and prescribed burns, a shaded fuel break maintains itself for five to 10 years on average,” Ostergaard says. “When you apply herbicide for longterm growth control, you can wait eight to 15 years before you have to retreat the property.”

Using the landscape to the forester's advantage is also important.“We like to do our intensive shaded fuel break work within 300 feet to 600 feet of a ridgeline,” Ostergaard says.“We manage the entire hillside area, but ridgeline areas are the best bet to stop or significantly slow down a fire.”

According to Minogue, fires naturally slow at ridgelines because of changing wind patterns. Enhancing this natural slowdown by decreasing the fuel load is an effective way to limit a fire's size and damage, and to decrease risks to firefighters.

When combining strategic placement of fuel breaks with herbicides, long-term protection is often the result. “Our recent studies with the Forest Service have shown that handclearing a ridgeline-shaded fuel break area costs $1,750 per acre on average,” Minogue says. “Herbicides, costing less than $100 per acre, can lengthen the time between mechanical maintenance two- or three-fold.”

According to Ostergaard, a sum-mer application of Arsenal® herbicide Applicators Concentrate (Arsenal AC) has helped Sierra Pacific control tough species such as chinkapin, alder, oak sprouts and green manzanita. “We use Arsenal AC for site prep for fuel breaks,” he says. “It allows us to eliminate the right amount of brush, while still leaving desirable food-source species for animals to browse.”

Similarly, Minogue uses a combination of Arsenal AC and glyphosate to control sprouting species, such as tanoak and black oak, and ceanothus species, such as whitethorn.

Minogue has also used Chopper® herbicide on manzanita in an oil emulsion
carrier. “It has been a big plus to find an herbicide that controls manzanita,” he says.

Craig Ostergaard, a regeneration forester with Sierra Pacific Industries, works with local fire safe counsels, charities and communities to help educate them on shaded fuel breaks and other fire control methods.

Made in the Shade

On Sept. 9, 1999, a fire near Winton, Calif., ignited by lightning, burned 115 acres, including four structures and a vehicle. Managing the fire cost nearly $500,000 but, according to Ostergaard, the cost and damage would have been far worse without shaded fuel breaks.

“If fuel breaks hadn't helped slow down the Winton fire enough for fire crews to control it, the CDFFP estimated that another 300 acres would have
burned,” Ostergaard says. “A subdivision with 40 homes is in that space, and the fire would have caused as much as $300 million more in damage before the next point where they could catch the fire. I guess you could say that the fuel breaks really worked!”

Ostergaard continues to work with local fire safe councils, charities and communities to keep shaded fuel breaks and other fire control methods top-of-mind.

“We want to be involved with the communities where forests grow,” he said.


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This page was last updated on Friday, October 20, 2006