Posts Tagged: wildfire
When wildfires burn in California, people often call them forest fires or brushfires, but the odds are high that an invasive weed is an unrecognized fuels component, says a UC Agriculture and Natural Resources scientist.
“We have all of the nasty non-native Bromus species here in California, and these weeds are key drivers of increasing fire frequency,” said Travis Bean, UC Cooperative Extension weed science specialist based at UC Riverside.
The invasive, non-native Bromus species aggressively outcompete native plants, forming dense stands that grow fast and dry out quickly, becoming highly flammable. Fire can move rapidly through these dense patches of dry grass, especially during windy conditions or on slopes.
“When you have understory of dry Bromus or other weedy grasses, their ease of ignition can allow fire to spread from areas like roadsides where ignition sources are plentiful to more pristine native plant communities,” Bean said. “Additionally, these fast-moving fires can throw embers that allows the fire to jump long distances or even reach high into the air, igniting structures.”
Identifying fire fuel
Bean would like to see the fuels in wildfires identified so people have a chance to consider managing them to mitigate the increasing frequency of catastrophic wildfire across the state.
With training, citizen scientists such as California Naturalists could help cities, counties, utilities and government agencies identify the invasive plant species that fuel urban wildfires.
“On a landscape scale, I would focus on managing Bromus anywhere human-caused ignitions occur,” Bean said. “Resources for management are scarce, and these species are widespread and can't be controlled everywhere they occur. Roadsides, hiking trails, and campgrounds are critical areas where people can start fires that spread, so It makes sense to concentrate management there.”
Cheatgrass (Bromus tectorum) is widespread at higher elevations, while ripgut brome (B. diandrus) and red brome (B. madritensis spp. rubens), also called foxtail brome, are pervasive at lower elevations. Along with other invasive winter annual weeds, they have successfully replaced large areas of the native vegetation in Southern California.
“When I talk to land managers about these species, they recognize that some areas will have to be sacrificed and it may not be possible to eliminate these species from the landscape,” Bean said. They are prioritizing areas with smaller invasive populations where there is an actual chance to eliminate them, or are managing larger populations for containment so they don't spread.”
Timing is everything
The key to reducing the spread of invasive, non-native Bromus species or any annual weed is preventing the plants from producing seeds, Bean said. “Whatever control method you chose, if deployed too early or too late, you gain nothing for considerable expense.” Too early and the plants may simply resprout, while too late and they will have already set seed and further contributed to next year's weed crop.
Herbicide is an effective and inexpensive means of control, though many prefer non-chemical methods. Hand pulling can be effective in small areas, but is discouraged for large patches due to the sheer amount of labor required and risks of actually spreading the weed seeds.
Another way land managers can try to prevent the weeds from spreading is by mowing or grazing with goats, sheep or cattle, Bean said, adding that using livestock can require more intensive management and proper timing is critical.
“For mowing and grazing, the key is to wait until the plants have started to flower, but the seeds are not mature,” Bean said. “If you mow when there's mature seed, you'll just spread the seed and make the problem worse. And once the seedheads mature, grazing animals won't eat it.”
Prescribed fire is another option for containing invasive grasses, but is generally discouraged as there's a very high chance of exacerbating the problem. These Bromus species are very fire-adapted and tend to increase following burns. Prescribed fire should only be used by professional land managers. If this strategy is used, a burn plan, permits and training are essential. If not done correctly, prescribed burns may escape control and become wildfires, producing smoke that impairs visibility on highways, impacts air quality and human health, and damages native vegetation.
“Timing is everything,” Bean said, explaining the temperature difference between the plant and soil surface. “The grass has to be dry enough to carry fire, but not so dry that the seeds have fallen from the plant to the soil surface, where temperatures are much cooler than just a few inches up in the air where the seedheads are. Some research has shown this strategy to have been successfully used for certain invasive grasses like barb goatgrass (Aegilops triuncilias), but is not recommended for Brome species.”
He expects the changing climate to lead to more invasive plant species. “Invasive plants can be more resilient during drought and can quickly bounce back when rain returns, overwhelming natives,” Bean said. “And invasive species are often key drivers of wildfires and increasing fire frequencies and intensities, which prevents the recovery of native plants.“
Why are we in this situation? Multiple factors are involved. We suppressed wildfires in our forests for 100 years, and stopped using prescribed fire as a tool for ecosystem benefits and fuel reduction. Further, we have been experiencing hotter summers (so the window for burning is wider) and we've continued to build into wildfire-prone areas with home construction, lot layout and community planning that often are not up to the fire challenge.
Is there hope? I present these as my take always, noting there is more detail to be seen at the UC ANR fire and other websites (e.g., CFSC). I was impressed by the three relatively clear battle grounds we need to attend to:
- Our homes: how we build, layout and landscape our homes
- Our communities: how we structure our neighborhoods and communities
- Our forests and beyond: how we manage (what I'll call) the forests and wildlands. Each has particular needs and opportunities
While the above focuses on prevention and management of fires, the Summit had good representation of the health sector, reminding us of the need to help humans, domestic animals and wildlife affected and traumatized by fire events.
The Summit was deemed by the participants themselves as very successful. Kudos to the many organizations who participated. There is momentum building with a genuine desire to work together to help the people of California.
Want to learn more? Contact some of our experts, who served as the chairs of the Summit coordinating committee:
David Lile, Leader, Sustainable Natural Ecosystems Strategic Initiative, UC ANR
Lenya Quinn-Davidson, fire advisor, Cooperative Extension, Humboldt County, UC ANR
Yana Valachovic, forest advisor, Cooperative Extension, Humboldt and Del Norte County, UC ANR
Want more? See UC ANR fire
The unspeakable loss of human life and the serious challenges being faced by survivors has dominated the Camp Fire conversation. Now, UC Cooperative Extension is beginning a dialog with many agencies involved to understand how such tragedies can be prevented in the future.
UC Cooperative Extension fire scientists and representatives of many California organizations conduct fire behavior research, study forest treatments – such as prescribed burns, timber harvest and mastication – and share best practices for home and community preparation. In the Butte County area where the Camp Fire took place, cooperating agencies include CalFIRE, the U.S. Forest Service, the Butte County Fire Safe Council, the Yankee Hill Fire Safe Council, Sacramento River Watershed Program, the Sierra Nevada Conservancy, the Bureau of Land Management, and others.
While the Camp Fire was devastating, it could have been far worse. Working together for decades, the partner agencies have improved community safety and resilience.
They have educated the public about defensible space, fire resistant homes, and evacuation plans. They have coordinated fuels treatments along evacuation routes and around the communities. Through their actions, they saved many lives and structures, protected the town's drinking water supply, and in some cases, provided access for hiking in areas that had been overgrown by brush.
“When you drive for miles through blackened, burned trees and then arrive in a thinning project area full of green tree tops, you know that these efforts are worth it, we are having success and we can make a difference together,” said Calli-Jane DeAnda, executive director of the Butte County Fire Safe Council.
Because of the Camp Fire tragedy, the partner agencies learned many lessons that can inform future maintenance and treatments to improve fire resilience in Butte County and other wildland areas. Kate Wilkin, the UC Cooperative Extension fire advisor for Sutter, Yuba, Butte, and Nevada counties, is able to point to projects implemented in the Camp Fire zone that saved lives and structures.
For example, one family in Paradise was featured by the news media for their successful advance fire planning, which even included the installation of sprinklers on top of the house.
“When I think about what saves a house, a sprinkler is a cherry on top of the cake,” Wilkin said. “If a house is constructed with a combustible roof and siding, if unprotected vents allow embers to get into the attic, or the landscape is not maintained, a sprinkler isn't going to save the house. The sprinkler's power from the grid or a generator will likely fail. High winds may even prevent the sprinkler's mist from hitting the house.”
Rather, passive resistance to fires through better building design, materials and maintenance greatly reduce structure loss.
“Maintenance is an unsung hero of fire resilience,” Wilkin said. “Individual actions at our homes matter.”
First 5 feet around a structure
State law requires homeowners in wildfire areas to clear 100 feet of defensible space around their structures. Most towns in wildfire-prone areas also have their own defensible space codes. Wilkin said where she lives in Grass Valley, anyone with less than an acre of land must maintain their entire property as defensible space.
This guideline is a start, but there is more that people who live in wildfire-prone areas can do to make their homes resilient to fire. UC Cooperative Extension scientists recommend creating a five-foot buffer immediately surrounding the home almost completely devoid of plants and anything that can burn - including wooden fences, firewood, deck chairs and pillows, brooms and other wooden tools.
This extra precaution is important as embers from a distant wildfire can land on or adjacent to a house and ignite combustible items which in turn ignite the home. It was evident in the Camp Fire that the first five feet around homes was a critical factor in the survivability of structures.
The zone can include noncombustible materials such as rock mulch, stone pavers, cement, bare earth, gravel or sand. Low combustibility materials, such as irrigated and maintained lawn or herbaceous plants less than five inches high, are okay. All leaves, needles or other vegetation that falls in this five-foot zone must be removed during the fire season.
“The non-combustible space adjoining the house may be the difference between losing it and all the contents to a wildfire versus returning to the property with the home unscathed,” Wilkin said.
Community fire resilience
Fire survival measures can also be taken at the community level.
In Paradise, the Butte County Fire Safe Council funded CalFIRE crews to thin a number of areas in the watershed below Paradise Lake in 2013 and 2014. Taking these actions allowed an area for firefighters to start a defense and start putting out the flame front, Wilkin said.
“A CalFIRE chief told residents, ‘You provide the offense, we provide the defense.' Homeowners and communities need to get everything set up for successful firefighting,” she said.
Forest thinning has the added benefit of improving recreational opportunities. Near Magalia Pine Ridge School, an 11-acre mastication project in 2018 funded with $30,000 from the Butte County Fire Safe Council cleared overgrown vegetation around the school. This helped strengthen the area's public assembly location, which was identified on the community's evacuation map, and opened up access to a forest hiking trail that was blocked by tangled brush.
The open space dramatically slowed the raging Camp Fire when it approached the school, which is now one of the only schools open in the Paradise Ridge community.
Forest thinning also protected the drinking water for the town of Paradise. A combination of projects undertaken by U.S. Forest Service, Sierra Pacific Industries and the Butte County Fire Safe Council aligned to allow fire fighters to combat the fire and ensure that the source of drinking water was protected.
Concow wildfire safety zone
In 2013 and 2014, the Butte County Fire Safe Council and Yankee Hill Fire Safe Council created a wildfire public assembly safety zone in Concow. The work was completed by inmate crews. During the Camp Fire, dozens of lives were saved when sheriff deputies, firefighters and citizens were able to shelter in the area.
“Wildfire safety zones are pretty uncommon and we may want to create more in wildfire prone areas,” Wilkin said. “But there is a hitch.”
CalFIRE is reluctant to designate temporary refuges because they don't want people to rely on them in place of evacuation. During a quick-moving firestorm, it could be an area where people can shelter if they cannot get out.
“It's a complex and dangerous puzzle,” Wilkin said. “In Australia, they had a similar idea and some places where people sheltered in a fire caused them to die.”
Wilkin is working with Paradise parks to identify areas ahead of time with enough space to meet new national firefighter standards to protect people's lungs from superheated air.
“Historically, we thought sufficient space was four times as great as the flame heights. If you have a Ponderosa pine that's torching 150 feet high, you would need 800 feet around the people,” Wilkin said. “New research has found that the safety zone calculation must also consider potential wind speed and slope. Significantly more space may be needed.”
California is searching for solutions to the wildfire crisis. Livestock ranchers believe they can help.
At the 14th Annual Rangeland Summit in Stockton in January, more than 150 ranchers, public land managers and representatives of non-profit organizations that work on land conservation gathered to share research and experiences that outline the value of cattle and sheep grazing on rangeland.
Since California was settled by Europeans, cattle and sheep have been an integral part of the state's history.
“Cattle can control brush,” said Lynn Huntsinger, UC Cooperative Extension specialist at UC Berkeley in a presentation on brush management. She discussed research she conducted in the early 1980s to understand the role of cattle in Sierra Nevada brush control.
“We need to make livestock into firefighters,” she said. “Constant, deliberate, targeted grazing is needed for fire management.”
However, thick, overgrown brush requires intensive treatment that cattle can't handle on their own.
“You have to start from a good place,” Huntsinger said. “Start early, such as post fire. Plan when you have a blank slate for the forest you want.”
The tragic loss of homes and lives to wildfire in the last few years has increased the public demand for answers and action. However, the reasons for greater frequency and intensity of wildfire are not well understood.
“Is it climate change? Past decisions? Land use? What can we do about it?” asked UC Cooperative Extension specialist Van Butsic. “Research.”
At the summit, Butsic presented the results of his recent research to determine whether ownership has an impact upon whether land will burn. He and his colleagues studied the burn histories of forest and rangeland areas that were matched with the same characteristics, except in ownership.
“We controlled for all factors – slope, elevation, the likelihood of ignition,” he said. “We found that on forest and rangeland, federal ownership led to .3 percent higher fire probability. Ownership is dwarfing the impact of climate change.”
There is still much more research to be done.
“We can't say the impact of grazed vs. ungrazed land,” Butsic said. “We also need to look at fire severity as well as fire frequency.”
The UC Cooperative Extension advisor in Modoc County, Laura Snell, shared preliminary results at the rangeland summit that provide information for landowners making decisions about returning livestock to burned areas.
She and a team of colleagues studied the fire history of U.S. Forest Service and Bureau of Land Management rangeland in Lassen and Modoc counties where fires had burned through 5, 10 and 15 years before. The dataset included information about whether the land was “rested” for two years after the fire, or whether livestock were returned to graze soon after the blaze.
The scientists set out to determine whether fire intensity and climate at the site (measured by soil temperature and moisture) had an impact on the future diversity of plant species and growth of cheat grass, an invasive species that animals don't like.
“No matter what we did, graze or not graze, after 15 years, the species richness stayed the same,” Snell said. “Grazing was not the driving factor.”
The results are also important in terms of fuels accumulation and the prevention of future wildfires.
“Federal land managers have typically used a policy to rest the land for two years after a fire. During the interval, the fuels sometimes burn again and livestock producers have to wait another two years,” Snell said. “Our research showed you don't necessarily need to rest the land after the fire.”
Two ranchers who were recently impacted by wildfire presented their experiences and perspectives during the rangeland summit.
Mike Williams of Diamond W Cattle Company had livestock on 6,500 acres of leased land in Ventura County when the Thomas Fire ignited on Dec. 4, 2017. Over more than a month, the fire burned 281,893 acres and consumed 1,000 structures.
Williams had stockpiled feed on certain pastures by limiting grazing, which during the fire turned into hazardous fuel.
Adam Cline, rangeland manager for the Yocha Dehe Wintun Nation Preserve in the Capay Valley, had a similar experience when the County Fire burned more than 90,000 acres in western Yolo and eastern Napa counties in June and July 2018. To reserve feed for later, Cline had left 2,500 pounds per acre of residual dry matter on grazing land as a drought mitigation strategy. He said he plans to reconsider this grazing plan.
“Now, cattle feed looks like a lot of fuel,” he said.
Shades of brown and grey cast over bricks, cement, remnants of metal roofs and steel beams from manufactured and modular homes, collapsed stucco walls, BBQs, shells of washers and driers, along with an occasional tea pot — that is what you can see in and amongst living, but singed Ponderosa pine and California black oak trees where the Camp Fire burned. How did California's most deadly fire happen and what might be done differently to ensure a better outcome? These are difficult questions that California will wrestle with for a long time to come.
Last week I was able to tour some of the burned area in Paradise and Magalia to evaluate why some homes survived and others did not. This gave me a chance to look at homes that survived largely on their material selection, design details, the owner's maintenance efforts, and not necessarily with the aid of a fire crew or resident that stayed. Many of the buildings that were burned were lost on the first day or two of the fire while emergency response was focused on evacuating the communities. It will take months to make sense of this mess and tragedy, but during my tour some conditions rang true to me.
Wildfire is not uniform
Not all fires are the same and not all houses experience the same type of fire. When you are looking at home losses and survivors, keep in mind that each home may not have had the same fire exposure. Some homes experienced significant ember exposure, while others ignited because their neighbor's home succumbed to fire and the heat of their neighbor's house caught their house on fire, while others were protected from the wind and its deadly embers. Paradise and Magalia have blocks and blocks of nothing but foundations, but amongst these bleak conditions are a few intact or partially damaged homes that have a story to tell.
California building code
Wood mulch and landscape plants
Our tour also confirmed that landscaping plants and wood mulch placed right next to the house creates vulnerability. While looking at the rubble of a home, it can be difficult to tell what happened; however, we saw several surviving houses with broken glass or otherwise damaged dual-pane windows that experienced heat exposures sufficient to crack glass in the windows, but the home still survived during these first two days when fire crews were rightly focused on community evacuation and not structure protection. For the houses that did not survive, we can interpret that in addition to the vulnerabilities in vents or a roof, heat can easily break glass in windows, especially if those windows are single pane, and can likely created a pathway for fire to enter the houses.
Home placement makes a difference
A home at the top of a canyon or gulch can easily be overwhelmed by wildfire by taking on additional heat as the fire approaches and being blasted with embers. This is not a new concept, but the homes in the broader Paradise region were especially vulnerable when they were located above these gulches and canyons. Enhanced vegetation management is highly recommended that includes a 5-foot non-combustible zone immediately adjacent to the home.
For me, thinking about Paradise in the abstraction was easy. Visiting it was different. The name says it all. After my visit I could understand why someone would choose Paradise or Magalia; the views are awesome, the air is clear, the forest and woodlands are amazing. I can only imagine that the community was (almost) perfect. Rebuilding a more resilient community will take considerable thought, effort, and some radical new ideas.