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How Vulnerable Are Other Parts Of The Bay Area To Wildfires?

by Sasha Berleman on October 24, 2017

A view of the Atlas Peak fire in Napa. (Photo by Joann Tippett)

How vulnerable are other parts of the Bay Area to wildfires like the ones devastating the North Bay counties? What can people do to better protect themselves this year and in future years from large-scale fires?

These are great questions. Unfortunately, other parts of the Bay Area are absolutely vulnerable to devastating fires not unlike those seen in the North Bay this month.

In particular, I would put the East Bay area at the top of that list based on its fire history (Berkeley Hills Fire and Oakland Firestorm) and the time that has elapsed since these last serious fires, but likely other areas as well.

We live in a landscape that is adapted to frequent fire, yet for a century we have been suppressing fire as much as possible, thinking we could do this indefinitely without consequence. As a result, most of our undeveloped lands across the Bay Area, and much of Northern California even, have accumulated unnatural fuel loads — dead woody debris and leaf material as well as encroaching trees that collect over time.

To counteract this accumulation of fuel on the landscape, we can conduct fuels treatments — grazing and browsing of animals, mechanical thinning, pile burning, and prescribed burning — to mimic the fire-dependent process, reduce the amount of dead material and restore an ecosystem balance. When we conduct fuels treatments on a regular basis, our woodlands and forests are healthier and safer and more resilient against serious fires. In this scenario, when wildfire does occur it burns at severities appropriate by plant community. We can still expect high-severity fire in chaparral, because that is what chaparral is adapted for, but we can expect fire behavior and associated severity to decrease as fire approaches woodlands and mixed-evergreen forests. On the other hand, if we do not actively manage our landscapes to minimize fuel loading, we set ourselves up for catastrophic wildfire where larger areas, including areas that typically prefer burning at low-severity, are more likely to burn at high-severity.

Here in the Bay Area, there isn’t a “no fire” option. Because of our Mediterranean climate — wet, cool winters and hot, dry summers — fire will always be a part of our world here. Additionally, as climate change affects our summers by extending that hot, dry season and causing hotter, drier weather within it, our fire season is getting longer and becoming more extreme.

Furthermore, we can add to that our Foehn winds, which we call the “Diablo” winds in the Bay Area (alternatively known as Santa Ana winds in Southern California). Foehn winds happen every year around this time — they’re the warm, extremely strong, and often very dry downslope winds we feel come raging through at 50 to 60 miles per hour. Consider all of this together — cool, wet winters stimulating growth, hot, dry summers resulting in dried vegetation, and Foehn winds that encourage dramatic fire behavior — and it is impossible to deny that our climate sets a perfect stage for fire with the effects potentially even stronger under the influence of climate change.

A prescribed burn on Bouverie Preserve in Sonoma County. (Photo by Sasha Berleman)

A prescribed burn on Bouverie Preserve in Sonoma County. (Photo by Sasha Berleman)

If you would like to better protect yourself from wildfires in the future, there are lots of things you can do! On the home front, make sure you are regularly cleaning and clearing debris and fuels around your home. I recommend going to firewise.org and spending some time reading through the information and materials on that site. They give great instructions for creating “defensible space,” as well as types of home construction and landscaping that can make a huge difference in how your home fares in the face of fire.

Beyond your home, voice your support for fuels treatments of all kinds across undeveloped lands. To date, land managers face immense backlash when the public hears of planned fuels treatments. It’s time to start supporting this work that so desperately needs to be done. Let your fire departments and politicians know that you support fuels treatments. Let your neighbors know how important they are. Educate yourself on the ecological adaptations of our landscapes to fire. Recommended reading: Introduction to Fire in California by David Carle.

Fire will always be a part of our world here, but we have a choice. We can learn to live with fire in a firewise manner, or we can continue to live against it and suffer the consequences. I’ve seen the immense outpouring of love and coming-together of community that we are capable of through the tragedies of the last month. I’d like to believe that we can use that same strength to come together, empower ourselves, and revolutionize our relationship with the land around us such that we can prevent this from ever happening again.

Sasha_Berleman-fire-ecologist-headshotSasha Berleman works for Audubon Canyon Ranch (ACR) as a fire ecologist. She has her PhD in wildland fire science from UC Berkeley. She conducted her graduate research on prescribed fire use in California landscapes for restoration of ecosystem health. She has been an active participant in Prescribed Fire Training Exchanges (TREX) since 2010, with most being located in Northern California (Shasta, Trinity and Klamath regions). She is a wildland firefighter with “Fire Effects Monitoring” and “Squad Boss” qualifications. She spent the summer on the Redding Interagency Hotshot Crew and additionally has approximately 600 hours of hands-on prescribed fire experience. Sasha is a board member of the Central Coast Prescribed Fire Council. 

Ask the Naturalist is a reader-funded bimonthly column with the California Center for Natural History that answers your questions about the natural world of the San Francisco Bay Area. Have a question for the naturalist? Fill out our question form or email us at atn at baynature.org!

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Kichil on October 26th, 2017 at 7:28 pm

Wow, no more “Bay Nature” for me. This artical is promoting practices which degrade the ecological integrity of wildlands. I will be siding with fire ecologists such as Chad T. Hanson and at least 260 other scientists on this one.

Richard Halsey on November 2nd, 2017 at 8:05 pm

This is the second time there has been an article in Bay Nature that has ignored the last 20 years of fire science to promote the false notions that the Bay Area, a region with one of the lowest lightning frequencies in the state, had short fire return intervals and that fire suppression there has created unnatural levels of vegetation. The first time was the 2009 article by Lester Rowntree. We tried to provide the research, but your editor rejected our offer to write a science-based article on the subject. Please read the two papers below and reconsider your position. It is out of date and promotes harmful land use policy.

Keeley, J.E. 2005. Fire history of the San Francisco East Bay region and implications for landscape patterns. International Journal of Wildland Fire 14: 285-296.
Available here:

Keeley, J.E. 1982. Distribution of lightning and man-caused wildfires in California, pp. 431-437. In C.E. Conrad and W.C. Oechel (eds), Proceedings of the International Symposium on the Dynamics and Management of Mediterranean Type Ecosystems. USDA Forest Service, General Technical Report PSW-58. Available here:

Mary McAllister on November 3rd, 2017 at 9:17 am

Thank you for this even-handed coverage of a topic that is very controversial in the Bay Area. I particularly appreciate the acknowledgement that fire is an inevitable event in California’s Mediterranean climate and the reminder that we are responsible for creating defensible space around our homes.

Fuels management projects have been controversial in the Bay Area because public managers have selected the destruction of non-native trees as their primary strategy. The use of herbicides to prevent trees from resprouting and to eradicate other non-native plants such as broom, is another source of opposition to fuels management.

If public land managers would change their fuels management strategies, public support would follow. For example, the City of Oakland has backed away from their original plans to clear cut all non-native trees from hundreds of acres of city-owned land, in response to the public’s opposition (and the cancellation of the FEMA grants that would have funded those plans).

The City of Oakland is engaged in a public process to develop a new vegetation management plan to address fire safety issues. The consultants who were hired to develop the plans started with a survey of public opinion that was taken by over 300 people. 90% of survey respondents support grazing to reduce flammable vegetation. 80% support manual removal of flammable vegetation and 59% support mechanical removal. Only 13% support the use of herbicides. The survey is available here: https://oaklandvegmanagement.org/wp-content/uploads/2017/06/OVM-PPT-PublicMeeting-June2017.pdf

If and when public land managers develop more sensible plans for fuels management that address real fire hazards rather than inappropriately scapegoating non-native plant species, public support will follow. Effective fuels management is unrelated to the nativity of the plant or tree.

Mary McAllister on November 3rd, 2017 at 5:57 pm

I agree that anyone with an interest in wildfire in California MUST read Jon Keeley’s work. In addition to the articles cited by Mr. Halsey, I also recommend his book, Fire In Mediterranean Ecosystems. It puts to rest the mistaken notion that California’s native plants are “fire resistant,” as claimed by some native plant advocates. As in all Mediterranean ecosystems, California’s native plants are fire adapted and fire dependent. Over 200 species of California native plants will not germinate without fire and they are gone from the landscape within 3-5 years if there isn’t another fire.

Keeley also studies specific wildfires in California to determine the contributing factors in those fires. He says herbaceous vegetation is the primary fuel of wildfires in the Wildland-Urban-Interface. He also says that we must quit building in places with the most extreme fire risk, such as canyons that create wind corridors.

Richard Halsey on November 4th, 2017 at 1:25 pm

Mary is correct that many native plants have various adaptations to respond to fire. But it is important to understand timing, especially for native shrublands like chaparral.

After a fire in a native shrubland there is usually a flush of post fire wildflowers and other herbaceous species. These disappear within 1 to 3 years as their seeds are cued to germinate by the chemicals in smoke. As time goes on, shrub species begin to dominate the landscape again, either from resprouting or via fire stimulated seed germination. If fire returns within 10-15 years, the shrubland is threatened with type converting to non-native weedlands.

This is why it is problematic to say chaparral species are adapted to fire, or need it for their survival. There is no longer a lack of fire in California. There is more in some areas than the system can tolerate. The idea that chaparral therefore needs fire creates the notion that any fire is a good thing. It is not. The natural fire return interval for coastal and inland chaparral is 30 to 150 years or more. Intervals less than that will compromise the ecosystem. Chaparral plant seeds can remain dormant in the soil for centuries.

Many native plants, however, can be used around homes if properly maintained and irrigated. Although no plant is fire resistant, many natives do a better job than traditional cultivars because it takes less water to keep them hydrated. Moist plants do not ignite until the water is driven out.

Maggie Rufo on November 6th, 2017 at 8:37 am

I would like there to always be an mention that this type of clearing, tree trimming, and tree cutting be done OUTSIDE of nesting season. The best time to trim trees is in the winter, when they are dormant, yet the mentality of most homeowners, and tree companies, is “Spring Cleaning”, which is the worst possible time to remove any vegetation. We need to consider all aspects of fire protection and that includes the animals that use our trees and bushes as homes and nest sites. How about we propagate a new phrase, such as “winter clearing” instead of “spring cleaning.”

Lee on November 7th, 2017 at 7:59 am

Fall Leaf clean-up around property is being ignored, by irresponsible property owners.
Defensible space is key: LEAN, CLEAN, & GREEN is how to maintain defensible green space around buildings.
Livestock (cows & sheep) degrade the land and water creeks.
Disappointing this article suggested animal grazing as a solution. Passive and destructive.

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