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Fighting Wildland Fires in Forests  

by IvyFPS
A Tale of Three Forests

Fighting Wildland Fires in Forests – A tale of three forests

An exhausted hotshot lays out her sleeping bag in a grassy field after a hard day on the fire line. At daybreak, as she rolls up her bag, she inadvertently picks up a small amount of plant material and seed. A wildland engine rumbles along a freshly cut dozer line. Its tyres kick up dirt as it traverses the rough terrain. Dust containing spores from an invasive pathogen settles on flat surfaces and finds its way into crevices in the vehicle’s undercarriage.

A tender drafts from a pond, and as it pumps in water, it also collects tiny aquatic organisms that attach themselves to the strainer and hard suction hose.

The accidental spread of invasive species happens every day on wildfires across the US. Non-native plants, plant diseases, and aquatic pests find firefighters and fire apparatus to be hospitable hosts, providing endless opportunities to travel to new areas and wreak havoc.

It’s not just by chance that we are there. Invasive plants have a symbiotic relationship with wildfire. Fire burns through an area, removing native vegetation. Firefighters come to suppress the fire, often unknowingly bringing propagule (spores, seeds, or plant material capable of reproducing) with them. In this sterile environment, there is little competition for light, water, or nutrients. It is a blank canvas for an aggressive plant species. Once established, these invasive species alter the ecological balance.

A Tale of Three Forests

Cheatgrass (Bromus Tectorum) is one of the most pervasive non-native plants in the US. A winter grass, it germinates in the fall and develops its root system through the winter months. In spring it sends up shoots earlier than native plants. It ‘shades out’ competing species by blocking the sun’s rays with its leaf blades and preventing native plants from becoming reestablished. By mid-June as its life cycle ends, the cheatgrass drops its seed and dries out, leaving a continuous dry fuel bed that is highly receptive to ignition and rapid-fire growth. The resulting mid-summer fires destroy more native plants, and the fire-adapted cheatgrass will germinate again when precipitation arrives in the fall.

This cycle results in dense, continuous grass stands that make fire ignition and spread more likely. Historically, in sagebrush-dominated ecosystems, large fires might occur every 60 to 100 years. In areas where cheatgrass has become the dominant species (approximately 50 million acres in the US), the interval between large fires is five years or less.

An invasive species is defined as a genus that is non-native to the ecosystem and whose introduction causes or is likely to cause economic or environmental harm. It is difficult to assess the economic costs of invasive species, but estimates put the worldwide total as high as US$1.4 trillion per year, with damage in the US calculated to be US$120 billion.

With such high costs associated with the problem, it is no surprise that the fight to prevent the spread of invasive species during fire suppression has taken on new urgency. An army of botanists and ecologists work to protect US forests and public lands. During wildfires these specialists are assigned as resource advisors or READs. They work closely with incident command staff, briefing firefighters on specific threats, and developing plans for hazard mitigation and decontamination. READs are embedded with fire operations personnel and are present on the fire line to observe and provide guidance.

Jennifer Hooke is lead botanist at the Crater Lake National Park. Crater Lake is a national treasure, hosting 750,000 visitors from around the world each year. When a thunderstorm ignited the Timber Crater fires, Hooke was intent on preventing new threats from entering the park during suppression activities. She and her colleagues educated firefighters about invasive species. They inspected proposed base camp, spike camp, staging areas, and helispot locations. One planned helispot was going to be in an open meadow teaming with multiple weed species. Concerned that plant material would become tangled in cargo nets and carried into the park, Hooke worked with air operations to instead secure a paved area for the helispot.

A Tale of Three Forests

Propagule of invasive plants can be carried on clothing or the soles of boots. Hooke’s team set up boot brush stations at staging areas. Firefighters were asked to brush plant material from their clothing and gear, and to clean their boots before entering the fire area. Hooke also insisted that every fire apparatus go through a ‘weed wash’ before entering the park. Weed wash stations are designed to remove dirt and plant materials from the undercarriage of vehicles. Grayback Forestry, a national provider of personnel and equipment for wildland firefighting, has several weed wash units deployed across the western US.

Each unit includes a large containment basin. Ramps are set up inside the basin. Beneath the ramps is an array of high-pressure water jets. ‘As a vehicle pulls onto the ramps, the upward facing jets are activated,’ explains Grayback’s emergency services coordinator Dale Ironside. ‘Attendants use pressure washers to clean wheel wells, running boards, and bumpers. Any visible mud or dirt is removed. Water from the process is captured and filtered before disposal. It is pumped through a coarse screen to catch large debris, and then through a 100-micron filter to remove remaining contaminants. Mud and debris in the catch basin are collected and placed in heavy plastic bags. These are tagged, sealed, and sent to a landfill for disposal.’

Ironside adds that READs routinely collect samples from the weed wash filtration systems. These samples are tested in a lab to see if they contain viable plant materials. Material in the samples often does germinate, validating the effectiveness of the weed wash system.

Kailey Clarno is district botanist for the Rogue RiverSiskiyou National Forest in Southern Oregon. Clarno served as a READ on the Chetco Bar fire where the READ team was tasked with containing two invasive plant pathogens, Phytophthora ramorum (Sudden Oak Death), and Phytophthora lateralis (Port-Orford-Cedar Root Disease). The origin of these pathogens is unclear, but studies point to a possible Asiatic source. Over the last decade, these diseases have been responsible for the death of more than one million oak and cypress trees in the western coastal regions of Northern California and Oregon.

A Tale of Three Forests

Phytophthora is a moisture-loving, microscopic fungus-like organism that lives in the soil. It produces copious quantities of spores that can be spread by water, wind-driven rain, or even heavy fog. Spores can also travel in dirt and dust stirred up by fire suppression activities.

With nearly 2,000 firefighters and hundreds of engines, tenders, and heavy equipment working across an incident spanning more than 298 square miles, the READs on the Chetco Bar fire faced a daunting task. The usual regiments of decontamination were followed but, instead of decontaminating vehicles only when they left the incident, trucks used in known pathogen zones had to be cleaned before moving from one division to another. Thousands of gallons of chlorine bleach were distributed to engine and tender crews. Every time water was loaded into an apparatus, it had to be treated with bleach before it could be used to fight the fire. At trailheads leading out of divisions known to be infected, firefighters had to pass through cleaning stations where they were asked to brush dirt from their clothing and gear and to spray their boots with bleach before hiking out. However, where the READs at Chetco Bar faced a menace in the soil, READs at the Spring Creek Fire in Colorado had a very different problem.

The wind-driven Spring Creek Fire, originating from an errant cooking fire, grew quickly to 108,000 acres, making it the third-largest wildfire in Colorado’s history. One of the primary water sources for firefighting was a reservoir home to two invasive species: the New Zealand mud snail and an invasive aquatic plant, Eurasian Milfoil. Once introduced, the New Zealand mud snail multiplies rapidly, attaching itself inside pipes where it can damage hydro-electric plants and other water systems. It has proven impossible to eradicate.

The Eurasian Milfoil grows in thick mats in the shallows of freshwater lakes. It chokes out other water plants and makes the lakes unusable for swimming or boating.

READs determined that to prevent the spread of these pests, fire apparatus would have to be decontaminated using water heated to at least 140°F. They specified that every surface of internal tanks and pumps should be exposed to this high temperature water for at least 10 minutes. When they approached the Rocky Mountain Type 2 IMT Team Blue with these requirements, logistics section Chief Travis Bailey came up with a unique solution.

Bailey had a vague recollection of hearing that high-temperature fluids were used in oil field hydraulic fracturing or ‘fracking’. He contacted a friend in the oil industry who directed him to McAda Fluids Heating Services. Although McAda had never undertaken an operation of this sort, they were confident they could meet Bailey’s needs. The company express delivered a 35-million BTU fluids heating unit with a 21,000-gallon (79,000-litre) frac tank to the base camp in Walsenburg, Colorado. Operators were brought in from Colorado and Texas to staff the operation.

Bailey said it took only 90 minutes to heat 16,000 gallons of potable water to 160°F (71°C). The hot water was pumped into each apparatus and kept under pressure so that no air space remained in tanks or lines. After 10 minutes the water was pumped out through a filtration system, and back into the frac tank for reheating. The process took about 18 minutes per vehicle. Start times, beginning water temperature, exposure time, and the temperature of the water as it was pumped out were documented. Following the internal decontamination, a high-temperature weed wash was used to remove contamination on external surfaces.

A Tale of Three Forests

Chief Bailey broke new ground with his innovative solution at Spring Creek, but the issue of invasive aquatic species contamination isn’t limited to fire engines. Firefighting aircraft are also affected.

If a helicopter makes bucket drops from one water source in the morning and is needed in another division in the afternoon, the pilot must consider contamination. If the first water source contained an invasive species, and the pilot dips into the new water source, it too may become contaminated. To prevent this, many rotorcraft are now deploying with more than one bucket. If reassigned to another area, they must fly to the helibase and switch buckets before beginning their next mission, leaving the original bucket to be decontaminated.

Dale Ironside says Grayback Forestry has recently built a mobile high-temperature pressure wash unit with a 500-gallon water supply to meet the need for this type of field decontamination. The unit is used to clean buckets, heli-wells, or portable fire-retardant plant equipment at remote locations.

In many ways fighting wildland fire can be thought of as a war. A fire flares up, we mobilise our forces, march in, and ‘kick some ash’. Then we take a bow and move on to the next fire, but there is so much more to it. Fire suppression is part of forest management, but it’s just the smallest corner of a much bigger picture. How we leave the forest and what happens after the fire is out can be even more important than how quickly it was extinguished. Once we begin to understand the impacts of non-native species, we will quickly realise that if we don’t control these pests, one day we may find we’ve won the battle but lost the war.

Written by Michael Davis who is a wildland firefighter, EMT, and public information officer living in Conifer, Colorado

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