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Moving beyond America’s war on wildfire: 4 ways to avoid future megafires

Prescribed burn conducted in the Sierra Nevada during a University of California Cooperative Extension prescribed fire workshop in November 2019. Photo by Susie Kocher.

Californians have been concerned about wildfires for a long time, but the past two years have left many of them fearful and questioning whether any solutions to the fire crisis truly exist.

The Dixie Fire in the Sierra Nevada burned nearly 1 million acres in 2021, including almost the entire community of Greenville. Then strong winds near Lake Tahoe sent the Caldor Fire racing through the community of Grizzly Flats and to the edges of urban neighborhoods, forcing the evacuation of tens of thousands of people – including one of us. Those were only the biggest of the 2021 fires, and the risk isn't over. A wind-blown fire that started Oct. 11 was spreading quickly near Santa Barbara on the Southern California coast.

As foresters who have been working on wildfire and forest restoration issues in the Sierra Nevada for over a quarter of a century, we have found it painful to watch communities destroyed and forests continuing to burn to a crisp.

The main lesson we gather from how these fires have burned is that forest fuels reduction projects are our best tools for mitigating wildfire impacts under a changing climate, and not nearly enough of them are being done.

Thinned areas like this one in California's Genessee Valley were more resistant to 2021's Dixie Fire. Ryan Tompkins, CC BY-ND

Two historic policies, in our view, led the western U.S. to the point where its forests have become so overgrown they're fueling megafires that burn down whole communities.

Fire suppression

The first policy problem is fire suppression and exclusion.

Fire is an essential ecological process, and many of the ecosystems in the West are adapted to frequent fire, meaning plant and wildlife species have evolved to survive or even thrive after wildfires. But most people arriving in California during colonization, both before and after the Gold Rush of 1849, fundamentally misunderstood the nature of frequent fire forests.

As state and federal agencies evolved policies on forest management, they considered all fire to be an existential problem and declared war. The U.S. Forest Service kicked off a century of fire suppression in the West after the devastating fires of 1910, known as the “Big Blowup” or “Big Burn,” by implementing the 10 a.m. policy. It aimed for full suppression of all fires by 10 a.m. the day after they broke out.

Native people who practiced prescribed fire to manage forests were removed from their homelands, and burning was criminalized. California made prescribed fire illegal in 1924, and it remained illegal for decades until a better appreciation of its importance emerged in the 1970s.

Past harvesting practices lead to regulations

The second policy issue is the regulatory approach that grew out of past logging practices.

Foresters and early California communities were interested in forests for lumber and fuel wood. They sent the largest – and most fire-tolerant – trees to mills to be turned into lumber, which was used to build California's cities and towns.

Poorly executed logging in some areas led to concerns from residents that forest cover and habitat was shrinking. As a result, state and federal regulations were developed in the 1970s that require managers proposing forest projects to consider a “no action alternative.” In other words, maintaining dense forest habitat in the long term was considered a viable management choice.

A few walls of buildings are standing but most of the town is burned and melted rubble.
Little remained of downtown Greenville after the Dixie Fire. Justin Sullivan/Getty Images

On private land, few owners today thin the forest to levels that would mimic the more fire-resilient forests found in the Sierra at colonization. The California Forest Practices Act until recently required replanting after timber harvest to levels much more dense than were found at colonization. In other words, our current regulatory framework promotes maintaining high levels of forest density, when much more drastic removal of vegetation is needed.

Taken together, these policies have promoted 21st-century forests that are younger, denser and more homogenous – making them vulnerable to increasingly severe disturbances such as drought, insect outbreaks and fire. This new reality is exacerbated by a changing climate, which turns the regulatory assumption that active and widespread forest management is riskier than no management on its head.

Agency priorities change as the crisis grows

Just as forests have changed, so too have the agencies that manage and regulate them. The U.S. Forest Service has seen its budgets for fighting fires balloon while its capacity to proactively manage forests has been shrinking. The California Department of Forestry and Fire Protection, known as CAL FIRE, has also seen large increases in firefighting budgets, though the state legislature has recently moved to increase fire prevention funds, too.

Living in communities threatened by wildfires this summer, we are very grateful to firefighters who have saved our homes. Yet we also are concerned that more large, high-severity wildfires burning across the landscape mean less funding and staff will be available for proactive fuels reduction projects like forest thinning and prescribed fires.

A smoky valley and evidence of a fire
The Caldor Fire burned on both sides of Christmas Valley, but was stopped from burning into the community by firefighters using areas where fuels were reduced before the blaze. Susie Kocher, CC BY-ND

How do we get out of this mess?

The Dixie and Caldor fires that destroyed Greenville and Grizzly Flats provided evidence that forest fuels reduction projects can work.

Both fires burned less severely in areas with proactive forest restoration and fuels management projects, including near South Lake Tahoe and near Quincy.

Fuels reduction projects include thinning out trees, burning off woody debris and reducing “ladder fuels” like small trees and brush that can allow fire to reach the tree canopy. They create more open forests that are less likely to fuel severe megafires. They also create strategic areas where firefighters can more easily fight future blazes. And, because fires burn less intensely in thinned forests, they leave more intact forest after a fire for regenerating new trees and sequestering carbon. Prescribed fires and managed ignitions paid huge dividends for containing the Dixie and Caldor fires.

A line of fire on a hillside with trees silhouetted.
During the Dixie Fire, firefighters used an area that had been strategically thinned in the past to set backfires to prevent the wildfire from spreading into the community of Quincy. Ryan Tompkins, CC BY-ND

To manage fires in an era of climate change, where drier, hotter weather creates ideal conditions for burning, experts estimate that the area treated for fuels reduction needs to increase by at least an order of magnitude. We believe government needs to accomplish these four things to succeed:

1) Drastically increase funding and staff for agencies' fuels reduction projects, as well as outreach, cost-sharing and technical assistance for private forestland owners. Although the Biden administration's proposal for a Civilian Climate Corps proposes funding to bring in more young and unskilled workers, funding more federal and state agency positions would recruit more natural resource professionals, provide career-track opportunities and better add forest restoration capacity for the long term.

2) Reduce regulations on forest and fuels management efforts for both public and private land. While California and the federal government have made recent strides to streamline regulations, land management agencies need to acknowledge the biggest risk in frequent fire forests is doing nothing, and time is running out. Agencies need to drastically cut the time needed to plan and implement fuels reduction projects.

3) Invest in communities' capacity to carry out local forest restoration work by providing long-term support to local organizations that provide outreach, technical assistance and project coordination services. Funding restoration through competitive grants makes development of long-term community capacity challenging at best.

4) Provide funds and financial incentives for at risk communities to retrofit homes to withstand wildfires and reduce fuels around homes, communities and infrastructure.

Under a changing climate, we will have to learn to coexist with wildfires in the U.S. West, but this will require concerted action and a cultural shift in how we view and manage our forests and communities to be resilient.


Susan Kocher, Cooperative Extension Forester and Natural Resources Advisor, University of California, Division of Agriculture and Natural Resources and Ryan E. Tompkins, Cooperative Extension Forester and Natural Resources Advisor, University of California, Division of Agriculture and Natural Resources

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Posted on Wednesday, October 13, 2021 at 12:00 PM
  • Author: Susan Kocher and Ryan Tompkins
Tags: Ryan Tompkins (5), Susie Kocher (28), wildfire (161)
Focus Area Tags: Environment, Family

Wildfire Fuel Mapper helps landowners manage vegetation, reduce fire risk

A Sonoma County property owner, center, discusses reducing fire hazards on his land by Lake Sonoma with Stephanie Larson, UC Cooperative Extension director in Sonoma County, and Mike Jones, UCCE forestry advisor.

On the four-year anniversary of the devastating Tubbs and Nuns fires in Sonoma County, the University of California Cooperative Extension (UCCE) and Pepperwood Preserve are launching the Wildfire Fuel Mapper, a comprehensive toolkit to assist landowners in managing vegetation that may fuel wildfires. 

The October 2017 fires, which destroyed nearly 7,000 buildings and left 25 people dead, underscored the importance of wildfire mitigation, community safety and long-term resilience. To prepare for wildfire, the Wildfire Fuel Mapper toolkit connects Sonoma County landowners with resources, professionals, specialists and funding opportunities to subsidize fuel reduction projects.

Imagery shows buildings and streams so landowners can see how the landscape has changed over the years.

The only mapping tool available at a parcel scale for the county, the Wildfire Fuel Mapper contains detailed maps of vegetation types and landscape elements that help users assess fire hazards and tailor a plan to manage those fuels.

The tool can be accessed directly by residents and used to map parcels greater than three acres. Wildfire professionals and vegetation management specialists also can use the Wildfire Fuel Mapper to better support their clients.

“When we're working in Sonoma County, we start every project by using the Wildfire Fuel Mapper tool,” said Joel Holland, president of Wildfire Services. “This invaluable tool provides a vital starting point from which to engage and educate property owners.” 

The map report shows wildfires for the past 40 years and risk factors such as fuel, slope and powerlines.

To access a custom map report, available for download at either a parcel or watershed scale, visit  

“The Wildfire Fuel Mapper is designed for Sonoma County, but other counties could create a similar set of resources to help their residents prepare for wildfire,” said Stephanie Larson, director of UC Cooperative Extension in Sonoma County.

The Wildfire Fuel Mapper is part of a coordinated effort in Sonoma County to better provide the public with accessible maps and prioritization tools to reduce wildfire risk. UCCE is currently collaborating with Sonoma Water to develop a decision support framework – an integrated set of tools, including the Wildfire Fuel Mapper, that will expand to operate at the landscape scale, enabling landowners to make strategic investments in fuel load reduction, vegetation management and climate resilience. 

Ladder fuels can lead wildfire from the ground into tree canopies.

“This project helps address the critical regional approach we need to assist landowners, watersheds, and agencies to design and implement better vegetation management,” North Coast Sen. Mike McGuire said. “Our county will be more fire safe thanks to UC Cooperative Extension's efforts.”

This project is a collaboration between University of California Cooperative Extension (UCCE), Pepperwood and Tukman Geospatial, with support from PG&E, the Thornton Foundation and CAL FIRE

Posted on Thursday, October 7, 2021 at 8:32 AM
Tags: Stephanie Larson (12), wildfire (161)
Focus Area Tags: Environment

Can homes be designed to withstand wildfire?

This photo captured by a drone shows a house that survived the 2018 Camp Fire among others that were destroyed. Photo courtesy of Butte County

In 2018, the Camp Fire destroyed nearly 19,000 structures in Northern California, including most of the town of Paradise. The structures left standing by the conflagration provided researchers an opportunity to investigate how housing arrangement – such as the size of the lot, the distance to a neighboring home, and surrounding vegetation – influenced which homes survived. They also looked at whether changes to the California Building Code in 2008, through the addition of Chapter 7A, improved the chances of homes built in the wildland-urban interface to withstand wildfire.

Both housing arrangement and surrounding vegetation likely influenced the survival of homes during an extreme wildfire, according to new research from the USDA Forest Service and the University of California Agriculture and Natural Resources analyzing the Camp Fire aftermath, which will be published Oct. 3 in the journal Fire Ecology.

“Our team found a reason for hope and information that can help Californians, building contractors and policymakers better prepare for future fires,” said co-author Yana Valachovic, University of California Cooperative Extension forest advisor.

The 2008 code, which applied to the city of Paradise, requires the installation of vents that resist flames and embers and other elements that help harden a home to wildfire. This chapter of the California Building Code added requirements for construction materials to California's existing two-zone fuel and vegetation modification guidance, known as “defensible space,” which applies to the vegetation and fuels out to 100 feet from a home.

Aerial image over Magalia post-Camp Fire illustrates a gradient of fire damage to overstory vegetation with distance from destroyed homes. Photo by Owen Bettis, Deer Creek Resources

The researchers found that the age of the home was a significant factor in predicting survival. But the key year wasn't 2008. Improvements in performance happened earlier. Only 11% of single-family homes built in or before 1996 survived, compared with 40% for homes built after 1996. Older homes were, on average, placed closer together and had more overstory tree growth near the home. Overall, the greater the distance between structures, the lower the likelihood of a home being destroyed by the Camp Fire. And the less overstory tree canopy cover, the higher the likelihood of a home surviving.

During a wildfire, structures can be threatened by the flaming front of the fire and by embers that are lofted ahead of the fire and land on fuels such as vegetation or mulch next to the house, igniting new fires. Embers can also enter homes through open windows or vents. Heat radiating from adjacent burning buildings or vegetation can also impact home survival.

“Despite the unpredictable nature of wildfire, strong associations with home arrangement and overstory vegetation cover indicate home survival is at least somewhat predictable,” said lead author Eric Knapp of the USDA Forest Service. “The silver lining is that this also suggests steps can be taken to substantially improve the odds of homes surviving a wildfire.”

One of the biggest drivers of home loss in the Camp Fire was the heat radiating from the large number of structures that burned. Over 73% of homes destroyed in Paradise had a structure burn within 59 feet. The distance to the nearest destroyed structure or total number of destroyed structures within 328 feet was a primary predictor of home loss.

“Exposure to the heat of a nearby burning structure can break glass in a window, for example. Once the glass is broken, embers or flames can enter the house,” said co-author Steve Quarles, emeritus UC Cooperative Extension advisor and retired chief scientist for the Insurance Institute for Building & Home Safety.

Steve Quarles, UC Cooperative Extension advisor emeritus, looks at a garage attached to an older house in Paradise where the radiant heat from a nearby fence and line of planted vegetation ignited and were sufficiently hot enough to break the single pane glass. Photo by Yana Valachovic

This finding suggests that denser developments, built to the highest standards, may protect subdivisions against radiant heat from a vegetation fire, but density may become a detriment once buildings ignite and radiant heat loads increase as well as the increased potential for direct flame contact.

“This research suggests a strong neighborhood effect, where the condition and proximity of an outbuilding or a neighbor's home can have a significant influence on a building's survival given the radiant heat exposure from a neighboring building burning,” Valachovic said.

Tree canopy cover was also associated with home loss, with a higher probability of home survival where tree cover was moderate or less.

“Trees provide shade, which is important where summers are hot. But to have the amenities trees provide without undue fire hazard, the key is to clean up the leaves and dead wood trees produce,” said Knapp. “This includes keeping roofs, gutters, garden beds adjacent to the structure and spaces under attached decks, free of leaves.”  

The researchers detected no significant increase in survival for homes built from 2008 to 2018, under the new building code, compared to homes constructed during an equal time period, 1997 to 2007, immediately preceding the adoption of the new code. Houses built during the last two decades resisted wildfire better than older homes, indicating an overall improvement in common construction standards and the performance of building materials.

At a home built after 2008, embers ignited combustible mulch and vegetation and led fire to break the first pane of double-pane windows.

“It is important for Californians to understand that homes and immediate surroundings need to be well-maintained to resist embers, survive extended radiant heat exposures and minimize direct flame contact,” Quarles said. “Fortunately, all building codes get better with time and Chapter 7A is no exception – Californians have benefited from it. California's Building Code is reviewed every three years, and it is evolving as new knowledge becomes available based on research and post-fire assessments.”

To enhance wildfire protection at the neighborhood scale, the researchers recommend coordinating efforts with neighbors.

“Because ember ignition of one house can put neighboring houses at risk, it is critical that fuel reduction happens at a community scale. Living with fire means doing all things possible to prevent one's house from catching fire,” said Valachovic.

There are simple actions that homeowners can take to protect their homes.

“From retrofitting with vents that resist ember entry or using tempered glass windows, to the simple things, like not placing bark mulch or woody plants next to homes, and using gutter guards to minimize leaf and needle accumulation in gutters, all will improve the chance of home survival,” Quarles noted. “It is a matter of how we choose to live in this environment.”

“Housing arrangement and vegetation factors associated with single-family home survival in the 2018 Camp Fire, California” by Knapp, Valachovic, Quarles and Nels G. Johnson is published in the journal Fire Ecology at

For more information:

Posted on Monday, October 4, 2021 at 12:02 PM
Tags: Steve Quarles (4), wildfire (161), Yana Valachovic (21)
Focus Area Tags: Environment

Landscaping with wildfire exposure in mind can protect homes

Creating defensible space around a home eliminates pathways for wildfire to burn directly to the home.

What can Californians do to improve the chances that their homes will survive a wildfire? Simple actions taken around the home can substantially improve the odds that a home will survive wildfire, according to UC Cooperative Extension advisors. 

During wildfire, structures are threatened not only by the flaming front of the fire, but also by flaming embers that are lofted ahead of the fire front and land on fuels such as vegetation or mulch next to the house, igniting new fires. Traditional defensible space tactics are designed to mitigate threats from the flaming front of the fire but do little to address vulnerabilities to embers on or beside a structure.

“Without attention to ember-related risks, defensible space efforts only address a portion of the wildfire threat—especially during wind-driven fires in which embers are the primary source of fire spread,” said co-author Yana Valachovic, UC Cooperative Extension forest advisor in Humboldt and Del Norte counties.

Zone Zero, the area within five feet of the house, should be cleared of combustible plants, planter boxes, mulches and wood that embers may ignite. Photo by Yana Valachovic

An updated University of California Agriculture and Natural Resources publication describes how embers, radiant heat, and direct flame contact ignite buildings and shares low-cost actions residents can take to create effective defensible space.

“The new publication is up-to-date with the changes in California's defensible space guidance, and it addresses Zone Zero, or the missing ingredient, in defense space,” Valachovic said. “The publication also provides a thoughtful discussion of plant lists and their limitations.”

The odds of a home surviving a wildfire can be substantially improved through careful attention to three things: careful design and maintenance of landscaping; awareness and management of combustible materials on the property such as leaf litter, wood piles and lawn furniture; and incorporation of fire- and ember-resistant construction materials with appropriate installation and maintenance.

“You don't have to spend a lot to protect your home from these wildfire threats,” said Valachovic.

Zone Zero, the area within five feet of the house, is the most vulnerable area around the home, according to the UC Cooperative Extension researchers. “During wind-driven fires, embers are the primary source of fire spread,” Valachovic said.

They recommend removing combustible plants, planter boxes, mulches and wood piles within the five-foot perimeter of the house and beneath attached decks.

To prevent a wood fence from leading fire to the home, consider replacing the five feet closest to the house with a noncombustible section such as a cinder block wall, metal gate or wire fence. Photo by Yana Valachovic

“While it may be a radical change, clearing the area next to the house will reduce the risk of ember-caused direct flame contact and radiant heat exposure, which are responsible for many home losses,” she said. “Because embers can accumulate at the base of an exterior wall, it is also important to create a six-inch noncombustible zone between the ground and the start of the building's siding.”

Colorful illustrations in the publication depict the three-zone defensible space strategy and show how spacing out trees on a sloped landscape can prevent fire from climbing from tree to tree to reach a house at the top of the slope.

The 12-page “Reducing the Vulnerability of Building to Wildfire: Vegetation and Landscaping Guidance” is available free for download at

Space plants, shrubs and trees so they don’t lead fire to the house or into crowns of trees.

“Landscaping for fire is part of an overall strategy aimed at reducing risk to the home,” said co-author Steven Swain, UC Cooperative Extension environmental horticulture advisor for Marin and Sonoma counties. “To reduce the risk of home loss, start at the house and work out from there,” he recommended. 

Swain, Valachovic and Stephen Quarles, UC Cooperative Extension advisor emeritus, are currently updating a publication on retrofitting houses for wildfire resiliency.

Steps for hardening houses against wildfire can also be found at the Fire in California website:




Posted on Tuesday, August 10, 2021 at 4:42 PM
Focus Area Tags: Environment

Proper land management can help forest owners ease wildfire risk following mass tree die-off

The massive die-off of conifers in the Sierra Nevada between 2012 and 2018 was predictable and unprecedented. Sadly, it is also likely to happen again, said UC Cooperative Extension forestry advisor Susie Kocher.

To help landowners manage forests in a way that minimizes the risk of such catastrophic tree die-off and the threat of uncontrolled wildfire, Kocher and two colleagues produced a 20-page publication that summarizes current research on tree mortality and outlines actions that can be taken to make the forest more resilient. The publication, Mass Tree Mortality, Fuels, and Fire: A Guide for Sierra Nevada Forest Landowners, is available for free download from the UC Agriculture and Natural Resources catalog.

A low severity prescribed fire consumes understory plants and branches on the forest floor, but leaves the mature trees intact. (Photo: Susie Kocher)

Written by Stanford graduate student Devin McMahon (now graduated), UC Berkeley Cooperative Extension forest health specialist Jodi Axelson and Kocher, the publication presents the extent of the die-off in the Sierra Nevada, and describes different factors that contributed to the vast loss of tree life – including land management practices, weather patterns and geography. It includes detailed reporting on the mortality's impacts on fuels and fire risk so landowners and managers can understand and develop strategies to prevent similar destruction in the future.

While about two-thirds of California's 33 million acres of forests are public lands held by state and federal government agencies, the rest is in private hands. Large companies manage millions of acres for commercial timber production, but about 9 million acres are owned by individuals. Nearly 90% of individuals own 50 acres or less; 87,000 landowners have 10 acres or more of forest.

“That's a really large number of people,” Kocher said. “That's one of the reasons why it is so difficult for landowners to manage land to improve forest health and reduce fire risk. It's not economical to do forest management on small areas.”

It's also very complicated. As natural processes play out over time in a forest with mass mortality, the fire risk changes dramatically.

“In the new publication, we help people understand the nuances of forest management so they understand what actions are most appropriate throughout the whole cycle,” she said.

Mastication, mechanically chewing up brush and branches, can be used to thin brush and trees. (Photo: Michael Bataglia)

Assessing and addressing the fire risk

The publication provides an overview of fire risk reduction. A table lays out the seven components of fire risk – fuel load, fuel moisture, fuel continuity, probability of ignition, weather conditions, topography and vulnerability to fire – along with mitigation actions for each that landowners can take.

Intentional, controlled burning, or prescribed fire, is often the most effective way to decrease fuel loads and future risk from fires, the researchers wrote. Other management actions include masticating – chewing up brush and branches with specialized equipment – felling and removing dying and dead standing trees, and thinning live trees.

The authors conclude with a glimmer of hope for the future of California forest lands. “Carefully planned forest management can reduce the amount and continuity of fuel on the landscape and limit the risk of destructive fire after tree mortality.”

A masticator head is being lowered onto small trees to shred them. (Photo: Michael Bataglia)
[This article was first published Sept. 10, 2020]
Posted on Tuesday, July 13, 2021 at 10:58 AM
Focus Area Tags: Natural Resources

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