Wildfires strike without warning across the American landscape, with a particular fury reserved for the arid southwest. Each year, the blazes bring with them the need for quick erosion control solutions and revegetation in their wake.
During the summer of 2002, at the site of the Rodeo-Chediski fire in Arizona where 497,000 acres were affected, Aero Tech Inc. workers seeded the entire burn. It was deemed important to “get seed on the ground before the noxious weeds came up,” explains Ted Stallings, owner and president of Aero Tech based in Clovis, NM.
“The fire was so hot,” he says, adding that the Burned Area Emergency Response (BAER) team determined the seed choice. “We threw the native seed on. It was all native seed except for some barley to get quick cover. Typically, we seed, then hydromulch. We may seed the entire burn, but we just hydromulch certain areas, like steep slopes.”
Approximately 15,000 to 20,000 tons of certified weed-free straw was placed on the Rodeo-Chediski site. The area the fire covered was so extensive that images of the blaze could be collected and tracked with satellite imagery, reported the US Geological Survey and NASA. The imagery helped identify burned areas for recovery efforts.
Revegetating a damaged area on a wide scale is not the only challenge posed by wildfires. “With most projects, you have the ability to plan ahead. Fires occur without warning and you need to be able to respond quickly,” says Ron Dietz, president of Dietz Hydroseeding based in Sylmar, CA. Coordinating plans with more than one individual or team, and doing so quickly, is essential.
“Usually there’s a lot of information and advice that is changing hands between people putting the plans together and various seed companies,” says David Gilpin, president of Pacific Coast Seed. “There is a very short time frame with delivery. There is a process that goes on, and then you have to jump at it.”
Like a paintbrush of destruction crossing a green canvas, wildfire often strikes remote areas, leaving a trail of charred earth that must be treated for recovery as well as for immediate erosion control. The sediment runoff from this kind of event can significantly affect not only forested areas but also populated land, as well as the streams and roads that support everyday life there.
“Wildfires usually occur in environmentally sensitive areas,” says Dietz. “Consideration must be taken regarding the type of seed and products that are used.”
Where access is a problem, aerial applications are a frequent solution. Colby Reid, reclamation division manager at Western States Reclamation based in Frederick, CO, provides an example of treatments applied to National Forest property. In July 2000, his company worked across approximately 1,600 acres of Santa Clara Pueblo land and Los Alamos National Laboratory property with 60% or more sloped land. The area was part of the Los Alamos Burn Aerial Revegetation Project for the National Park Service. The effort required 250 flights a day and 800 gallons of slurry per flight, for a total of 27 days. Approximately 47,650 acres burned as a result of the fire.
Seed was mixed with fibers, tackifier, fertilizer, and hydromulch in hydromulch tankers, and the resulting mixture was dropped from the air from Air Tractor airplanes. Aerial application was chosen because time was of the essence and there were problems with accessibility by ground.
Rick Bilodeau of Rantec Corp. in Ranchester, WY, says the company supplied Super Tack for the Los Alamos project. “That will tack the fibers together and tack the fiber to the soil. Super Tack is a guar-based tackifier,” he says. “It has superior tensile-strength qualities. It was really rugged terrain. You want the slurry to stay on the slope and not run off, and once it’s cured you want it to prevent erosion. I believe we applied 60 to 100 pounds per acre [at the Los Alamos site].”
“It was a controlled burn that got away from the Forest Service,” says Reid. “It was during the monsoons when we were doing it. There was volunteer ground labor; they hand-seeded and -spread straw and a lot of wattles.”
When returning a landscape to its pre-fire state, not only are these treatments necessary to prevent erosion; young trees and shrubs can require soil treatments to effectively revegetate an area following a wildfire.
“It takes them about two years to establish themselves,” explains Hugh Ross, president and owner of Agrosoke International based in Arlington, TX, and manufacturer of Agrosoke crystals that are used to keep roots moist. “When you add these to the soil, you have a little water reserve for the plant,” he says, explaining that a plant’s roots grow through the crystals. “We capture the water that would have percolated away and hold it for the plant’s use.”
Soil amendments are also an option for wildfire-damaged lands. Mychorrhizae are soil-based fungi that aid a plant’s nutrient absorption by increasing the surface area of roots and breaking down difficult-to-capture soil nutrients. The fungi can be released into areas where they’ve been depleted to better establish plant growth, according to Grants Pass, OR-based Mycorrhizal Applications Inc., which has provided mychorrhizae for numerous revegetation projects.
The Edge of an Aerial Assault
Pilots must make many strategic considerations when applying straw to a wildfire-damaged area, not the least of which is wind speed, ensuring that straw lands where it is needed. For example, Revegetation Services, based in Mesa, AZ, typically seeds, when needed, before dropping straw from a net onto an affected area. When a protective cover is all that is required, mulch is dropped onto the affected area.
“There are many combinations of hydromulch slurries that can be and have been applied,” says Western States Reclamation’s Reid. “For the Cerro Grande [New Mexico] fire, the hydromulch slurry mix included water, hydromulch, fertilizer, seed, poly fibers, and tackifier. In addition to aerial work, a lot of ground work is implemented in these areas: ground mulching with straw and hydromulch, hand seed and rake, wattles, straw bales, silt fence, and contour tree felling.”
Revegetating the area affected by the Coal Seam Fire in Glenwood Springs, CO, which Reid said was caused by an underground coal fire that had been burning for several years, also posed a challenge to pilots.
“Treatment was [applied to] approximately 500 acres of BLM [Bureau of Land Management] land in steep areas above the town,” he explains. “The project used hydromulch slurry, with guar tackifier from Rantec, organic fertilizer, and a native seed mix. The project was completed in eight days. The most challenging aspect was for the pilots, due to the steep terrain.” Overall, says Reid, the treatment applications went smoothly and proved very successful.
Aerial applications for erosion control after a wildfire are a global solution. Aero Tech has worked on fire-damaged landscapes not only in the American southwest, but also in Africa and South America. The company operates two helicopters and 11 airplanes.
Revegetation costs vary depending on the size of project, the company, and the products selected for use, particularly when aerial applications are involved.
“Costs can range anywhere from $5 an acre to $15 an acre, depending on the terrain and distance we have to ferry the [material],” says Stallings. “A light and fluffy seed, compared to heavier seeds…can be put on faster. The bigger project is going to be less per acre than a small project.”
Seeding for Stability
Seeding wildfire-damaged areas can be approached through a variety of methods.
“We sometimes start immediately, and sometimes it may be four or five months later after the fire, all depending on budget and contracts,” says Stallings. “In 2004, we were seeding the Peppin Fire in Ruidoso, New Mexico, on one side of the mountain while our aircraft and helicopters were still fighting the fire on the other side of the mountain!”
After the Peppin Fire, two seed mixes were used, one on the land outside the wilderness area and another inside the area, according to Bill Agnew, general manager for Granite Seed, based in Lehi, UT. The US Forest Service purchased a combination of mountain brome, slender wheatgrass, and sideoats gramma, all native grasses, as well as orchard grass and mountain mahogany for the outside mix. The seed mix used inside the wilderness area included mountain brome, slender wheatgrass, sideoats gramma, and barley that was used as a cover crop, says Agnew. Barley’s appeal lies in its ability to grow quickly.
Stallings, too, describes the erosion control process following a wildfire as a race against the rain, noting that so much soot is left on top of the soil that if the damaged landscape receives a 2- to 4-inch rain, flooding could wipe out areas such as shopping centers or water treatment plants.
During a huge wildfire that struck San Diego in 2003, Los Angeles-based Stover Seed Co. was one of the distributors that supplied seed to Northstar Impex Corp. contractors for revegetation. Because of the area’s dense population, there was great concern over protecting the wildfire-ravaged land from damaging property.
“General practice is to get some soil down in critical areas and let the rest come back as is,” says Stephen Knutson of Stover Seed, adding that for the San Diego project, a variety of annual grasses and a few perennials were seeded with the goal of allowing native plants to take hold in the soil once again.
The seed was sold directly to the county. “It’s a trend that counties buy the seed they want and dole it out to different contractors to apply,” explains Knutson.
Seeding to prevent property damage was an issue for Revegetation Services workers involved in repairing an area after the fire that raged between Heber and Show Low in the White Mountain region of Arizona. The wildfire-damaged ground was burned, and water running off the site threatened towns downstream.
“You run into a situation when the ground will not accept any moisture,” says Kurt Anderson, president of Revegetation Services. “It’s an urgent need when you have expected rains.”
The project areas were seeded with native grasses shipped to the site by Granite Seed ahead of Revegetation Services beginning its work in the area.
“We had to attack by both ground and air. We had ground crew putting straw in and air crew dropping straw,” says Anderson. “Access is a big problem with almost every fire we’ve been involved with.
“Within a week after we got onto that watershed, the streams stopped running and the roads were repaired. The straw caused the rain to percolate into the burnt soil and therefore it didn’t sheet off.”
On most of his projects, Anderson says seed that can germinate quickly is used similarly to that of a cover crop. “The native will come in later,” he says. “They want to get the roots into the soil and start holding some of that water.”
When Less Is More
The Croy Fire in Morgan Hill, CA, about 20 miles south of San Jose, charred about 3,000 acres.
“It was very hilly, so the fires went up these canyons very quickly,” says Carol Presley, an environmental engineer and Certified Professional in Erosion and Sediment Control with the Santa Clara Valley Water District based in San Jose.
Before the fire, the plants that had been growing on the chaparral, which has characteristically dry summers, are more flammable than many other species and “very adept at readapting themselves after a fire,” explains Presley. Although it may seem logical to want to revegetate with fast-growing grasses, this is not the course of action she advises for this type of landscape.
“One property owner did apply Italian rye, which was a complete mistake. It suppressed the natives. Don’t be quick to install fast-growing weedy grasses, because you could really damage the existing ecosystem, particularly delicate ecosystems like a chaparral,” says Presley. “The worst thing to do is produce weedy grasses that persist; then they provide a fire hazard in the future.”
After the Croy Fire, workers installed weed-free straw mulch from Pelletized Straw LLC “to provide that first year of erosion protection so that the native [plants] could come back on their own,” she explains, adding that the plants would have included manzanita, ceanothus, and chamise. Mulch was trucked up and down the hilly terrain and most of the mulch was hand-applied by conservation corps workers.
“We did a little bit of hydroseeding on the roads, mostly with plant-based tackifier. There were already roads in place. The idea was to keep our treatments to where the firebreaks were or along the roadsides,” says Presley. “Sometimes the minimalistic approach is the best.”
A similar plan worked for a revegetation project in 2003. In November of that year, the Dietz Hydroseeding team worked on the Simi Fire revegetation project located along California Route 118 in Simi Valley and Moorpark.
“Because of the imminent threat of rain, there was a three-pronged approach to the methods used. First, a bonded fiber matrix was used because of the ability to cover a large area very quickly to prevent erosion and sediment flow. We were able to protect approximately 150 acres of areas immediately adjacent to roadways and drainage structures in about three weeks’ time,” says Dietz. “Second, in areas that were prone to heavy water flow, straw rolls or wattles and gravel bags were used in conjunction with the application of the bonded fiber matrix.
“Finally, areas with existing erosion problems that were exposed because the fire burned the brush and ground cover were addressed with more permanent methods such as regrading and rebuilding of slopes and drainage structures.”
While some areas were a challenge to access, most of the areas that needed to be addressed were adjacent to roadways, according to Dietz.
“Wildfires are a natural part of the ecology in southern California. Nature recovers very quickly in the burned areas, and generally the best approach is to leave natural areas alone,” he says. “Only areas with manmade structures such as roads, buildings, and drains require protection, and these areas are usually accessible.”
Indigenous native seed was used at a light rate as part of the Simi project. “Native seeds will germinate quickly with natural rainfall, and there is native seed on the soil surface,” says Dietz, adding that the ESC and revegetation methods used cost approximately $2,200 per acre, sans the rebuilding and regrading process costs. “Care must be taken not to interfere with the post-fire native species that exist in most fire-prone areas. The bonded fiber matrix was the immediate erosion protection, not fast germinating seeds.”
Never Enough Time
Erosion control begins when fire control ends. In February 2006, an escaped campfire in the Tonto National Forest about 12 miles north of Payson, AZ, burned 4,243 acres. Grant Loomis, forest hydrologist for the Tonto National Forest, was the team leader for the BAER team working on the project
“It was pretty unusual because it was in February. It was very odd to have a fire that time of year,” says Loomis, adding the wildfire began in a site that’s not typically a camping area. “Usually it’s snow-covered then. Drought conditions certainly contributed to it.”
The team removed floating debris from a nearby channel to reduce the risk of flooding, particularly to homes and the Bray Creek Ranch located downstream. The team also removed falling trees and limbs and placed treatments on road crossings that were at risk for blowing out.
“There is an intermittent stream downstream of the private property that we were trying to protect with these treatments,” he says, explaining that the BAER team identifies risks to life and property and proposes treatment solutions. If the team finds there is a “danger of noxious weeds invading the burned area” or emergency conditions, he says, the team can mitigate with seeding or different types of erosion control on the land.
Following the February fire, the team seeded the area first using a mixture of native and non-persistent annuals, similar to rye or barley, that would provide a quick ground cover for a couple of seasons and then die off.
“We’re supposed to get our treatments in before the first damaging storm. Typically fire season is followed immediately by heavy rains. If we’re going to mulch an area, we may not do other treatment,” says Loomis, adding that the seeding sought to create a temporary solution until the natural ground cover was able to recover. “Watershed conditions in this area usually recover to pre-fire conditions in five to seven years.”
The site, with its severely burned slopes, was not easily accessible. “The crew that did the work had to hike into the site,” says Loomis. “It was about a quarter- to a half-mile from the nearest road.”
Of course, the labor involved with a project of this size can be costly, particularly when compared with the cost of materials. “The majority of the cost is the labor,” he says. “Labor for this project cost $6,000 a day for the crews, and there were at least two days.”
Project labor came to approximately $15,000 for labor used to place wattles and for seeding. Loomis says the treatment spanned about 40 acres of forest of ponderosa pine, pinon, juniper, and oak.
“Straw wattles were about $26,000, and seeding was about $1,800,” says Loomis. “We try to keep some of the crews treating fire. We had two 20-person crews installing this for us.”
Ensuring the preservation and restoration of a wildfire-damaged area should leave a legacy of promise for the next generation, not the setup for future damage through the presence of noxious weeds. Whether it’s a crew of 20 working around the clock or a handful of dedicated volunteers hoping to save people’s homes, combining erosion control methods with maintaining a sensitive touch with regard to an already battered landscape is an approach worth considering.
