Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Tag Archive: fire

  1. Controlled burns limited severity of Rim Fire – Yosemite 2013

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    • In fire-prone forests, self-reinforcing fire behavior may generate a mosaic of vegetation types and structures. In forests long subject to fire exclusion, such feedbacks may result in forest loss when surface and canopy fuel accumulations lead to unusually severe fires.
    • Self-reinforcing fire behavior results mainly from effects of vegetation structure and fuels on fire severity and that this behavior is mediated by topographic setting and the time since last fire.
    • The best predictor of fire severity was how severe the area last burned– Low severity burning seems to be very effective at limiting the severity of subsequent fires.
    • Severe fires leave behind a new legacy on the landscape. Less frequent, more severe fires caused by human intervention can change the composition of the forest and make future severe fires more likely to occur. For example, shrubs, which grow quickly after a fire, can take over forestland and then burn again before trees are able to re-establish.

    December 8, 2017 Penn State  read full ScienceDaily article here

    Controlled burning of forestland helped limit the severity of one of California’s largest wildfires, according to geographers.

    Fire burning in forest. Credit: Alan Taylor, Penn State

    ….The researchers studying the Rim Fire, which in 2013 burned nearly 400 square miles of forest in the Sierra Nevadas, found the blaze was less severe in areas recently treated with controlled burns.

    ….”It points to the potential use of prescribed fires to reduce severe fire effects across landscapes,” he said. “You can fight fire with fire. You can fight severe fires using these more controlled fires under conditions that are suitable.

    Scientists examined 21 previous fires within the Rim Fire’s perimeter, which burned in and around Yosemite National Park. They found areas that had burned within the preceding 15 years fared better in the 2013 blaze.

    The best predictor of fire severity was how severe the area last burned, according to the findings published in the journal Ecosphere.

    Low severity burning seems to be very effective at limiting the severity of subsequent fires,” said Lucas Harris, a graduate student in geography and lead author on the paper.

    …”Fire severity has been increasing for about the past three decades,” Taylor said. “There are real questions about whether we are beginning to see a shift in vegetation types driven by fire activity fueled by fire suppression and climate change.”

    The researchers said severe fires leave behind a new legacy on the landscape. Less frequent, more severe fires caused by human intervention can change the composition of the forest and make future severe fires more likely to occur. For example, shrubs, which grow quickly after a fire, can take over forestland and then burn again before trees are able to re-establish….

    “If you have a high severity initial fire, that’s a real lost opportunity,” Harris said. “You are probably getting a vegetation change due to that first fire that’s going to cause more high-severity fires in the future and potentially the emergence of non-forest that could last for a long time.

    Lucas Harris, Alan H. Taylor. Previous burns and topography limit and reinforce fire severity in a large wildfire. Ecosphere, 2017; 8 (11): e02019 DOI: 10.1002/ecs2.2019

  2. California Fires and Climate Change

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    • Offshore winds are whipping up wildfires in California….Rising temps combined with fire suppression, increased development in wildland areas are making the West dangerously combustible.
    • [see my post on the No CA fires here; 2015 study found that a warming climate will likely make these “Santa Ana” offshore winds both more frequent and stronger, fueling potentially increasing destructive offshore wind driven fires by 64% ]
    • and here on fire tornadoes; [““Just like water flows from higher to lower elevation, winds flow down a pressure gradient as they go from high pressure to low pressure,” said Max Moritz, a wildfire specialist with the UC Cooperative Extension. “When they get concentrated, like through a mountain pass, they will speed up, like a river going through a narrow channel.” ]
  3. Mediterranean Climate Wildfires: what you can do to better protect your home and our communities

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    by Sasha Berleman, Audubon Canyon Ranch fire ecologist, for Bay Nature October 24, 2017 Read full BayNature article here

    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.

    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….

    …On the home front, make sure you are regularly cleaning and clearing debris and fuels around your home. ....go to firewise.org … 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....

  4. Sonoma County hazard plan foresaw deadly Wine Country fire

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    • some actions recommended in the 2011 report had yet to be completed, including mapping out accessible roads and bodies of water that could be used for fighting wildfires, and implementing long-standing recommendations to improve fire services, including possibly consolidating some fire districts

    by Joaquin Palomino and Kimberly Veklerov October 27, 2017 read full SF Chronicle article here

    On a hot September night in 1964, 70-mph winds pushed a cascade of flames through the dry vegetation of Mark West Canyon and into the outer edges of Santa Rosa, destroying more than 100 homes and burning 52,000 acres. Until this month, that blaze, known as the Hanley Fire, was the worst in modern Sonoma County history, and the path it carved was remarkably similar to the one the devastating Tubbs Fire would follow a half century later.

    ….As recently as last spring, a Sonoma County report on potential hazards facing the region cautioned that a fire comparable to the Hanley blaze could cause “catastrophic damage to the county and the city of Santa Rosa.”

    If multiple blazes broke out around the state during fire-weather conditions, firefighting resources in Sonoma County could be stretched beyond their capacity, the Hazard Mitigation Plan said. “It is not inconceivable,” it stated, “that a large uncontrolled wildland fire could overwhelm resources and cause significant damage.”…

    …The report also notes that parts of Sonoma County most prone to wildfires are heavily reliant on a shrinking number of part-time, volunteer firefighters, a problem seen across the county.

    To reduce the potential loss of life and property from a natural disaster in Sonoma County, the plan includes action strategies. Mitigation measures completed in recent years include:

    •A vegetation-abatement program in unincorporated areas that inspects properties and requires owners to remove dead plants, weeds and other potential fuel for fires. A pilot effort is in place in two areas that were not directly affected by the recent fires.

    •Stricter safety standards for new homes, particularly those built in high-risk wildfire areas. These include additional building restrictions on venting, roofing and siding materials.

    •Providing a free, roadside wood chipping service to help residents create or maintain a buffer around their homes, also known as a defensible space.

  5. ‘Like a blowtorch’: Powerful winds fueled tornadoes of flame in Tubbs No. SF Bay Fire

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    Peter Fimrite Oct. 19 2017 Read full SF Chronicle article here

    The Tubbs Fire that raged through Santa Rosa last week unleashed a series of fiery tornadoes powerful enough to flip cars, yank trees out of the ground and rip homes apart, fire scientists said Wednesday.

    Gusts of up to 73 mph were recorded at the weather stations after the fires broke out Oct. 8, but the extraordinary damage documented during postmortem evaluations indicated that much more powerful forces were at play….“It was no different than a hurricane, really, but instead of rain we had a fire event. I’ve been in this business 30 years and it’s the worst I’ve seen.”…

  6. Northern California firestorm ‘literally exploded’; 2015 study found warming climate to make “Diablo” offshore winds more frequent and stronger, fueling more destructive fires

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    • years of drought followed by record-breaking rainfall increased fuel load [after a century of fire-suppression combined with inappropriate siting of houses and other built infrastructure]
    • 2015 study found that a warming climate will likely make these “Diablo” offshore winds both more frequent and stronger, fueling potentially destructive fires

    Updated Oct 11 2017  Read full ClimateProgress article here

    …The fires ignited late Sunday night and into Monday morning and have since spread over 50,000 acres across Napa and Sonoma counties, destroying at least 3,500 structures and sending at least 100 to the hospital with injuries ranging from burns to smoke inhalation…

    …Fast-moving winds and low humidity aren’t rare in California, and neither are October wildfires, but it’s likely climate change made these fires even more destructive. After years of historic, prolonged drought, which studies have linked to climate change, California experienced record-setting rains that fueled the growth of grasses and underbrush — young vegetation that dries easily during the summer and is especially susceptible to ignition. Because warmer atmospheric temperatures can hold more water, experts have suggested that the cycle of drought followed by intense precipitation could be linked to climate change.

    Even the state’s characteristic winds — known in the northern part of the state as Diablo Winds and in the southern part of the state as Santa Ana winds — could be getting worse because of climate change. The Santa Ana and Diablo winds occur when high inland pressure pushes air down the sides of mountains (Mt. Diablo in northern California and Mt. Ana in southern California), whipping wind through the canyons and hillsides outside major population centers like Los Angeles and San Francisco. According to a 2015 study lead by researchers at University of California, Los Angles, UC Davis, UC Irvine, and the U.S. Forest Service, a warming climate will likely make these winds both more frequent and stronger, fueling potentially destructive fires....

    ….The National Wildfire Coordinating Group currently lists 179 active wildfire situations throughout much of the Western United States, from Colorado to Washington. The largest active fire in the United States is the Chetco Bar Fire in southern Oregon, which has burned over 191,121 acres and is 97 percent contained. As of October 6, wildfires have burned 8,469,590 acres across the United States — the third largest total acreage burned in the last 10 fire seasons….

  7. Industrial farming disrupts burn-regrowth cycle in grasslands

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    June 29, 2017 University of California – Irvine  see full ScienceDaily article here

    The world’s open grasslands and the beneficial fires that sustain them have shrunk rapidly over the past two decades, thanks to a massive increase in agriculture, according to a new study led by University of California, Irvine and NASA researchers published today in Science.

    Analyzing 1998 to 2015 data from NASA’s Terra and Aqua satellites, the international team found that the total area of Earth’s surface torched by flames had fallen by nearly 25 percent, or 452,000 square miles (1.2 million square kilometers). Decreases were greatest in Central America and South America, across the Eurasian steppe and in northern Africa, home to fast-disappearing lions, rhinoceroses and other iconic species that live on these fire-forged savannas.

    A billion and a half more people have been added to the planet over the past 20 years, livestock has doubled in many places, and wide-open areas once kept open by fire are now being farmed,” said James Randerson, Chancellor’s Professor of Earth system science at UCI. “Our fire data are a sensitive indicator of the intense pressure humans are placing on these important ecosystems.”…

    Sharp increases in the number of livestock, the expansion of croplands, and new buildings and roads have fragmented the savannas and reduced highly flammable dried grasses. The expanses have become prized assets for private landowners who want to prevent brush fires. Unlike international efforts to combat tropical deforestation, there’s been less focus on protecting these vast semiarid stretches.

    “Humans are interrupting the ancient, natural cycle of burning and recovery in these areas,” Randerson said. Losing a fourth of the planet’s fires has benefits, increasing storage of dangerous carbon emissions and reducing lung-damaging smoke. But the drop-off in smoke in the atmosphere also allows more sunlight to reach the Earth’s surface, causing more global warming.

    The change is not uniform. Consistent with previous reports, more wildfires have occurred in the western U.S. and across North American boreal forests, where climate change is lengthening the fire season and drying out flammable vegetation faster.

    N. Andela, D. C. Morton, L. Giglio, Y. Chen, G. R. Van Der Werf, P. S. Kasibhatla, R. S. Defries, G. J. Collatz, S. Hantson, S. Kloster, D. Bachelet, M. Forrest, G. Lasslop, F. Li, S. Mangeon, J. R. Melton, C. Yue, J. T. Randerson. A human-driven decline in global burned area. Science, 2017 DOI: 10.1126/science.aal4108

  8. Spotted owls benefit from forest fire mosaic

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    • Maintaining a complex mosaic of forest patches with smaller patches of high severity fire can help sustain California Spotted Owls in the greater landscape,

    Posted: 31 May 2017 05:44 AM PDT  full ScienceDaily article here

    Fire is a crucial part of the forest ecosystem on which threatened spotted owls rely, but climate change and decades of fire suppression are changing the dynamics of these forests. A new study examines California spotted owl habitat use and shows that while owls  avoid the badly burned areas left behind by massive stand-replacing fires, they benefit from habitat that includes a mosaic of burned patches of different sizes and degrees of severity.

    …”Maintaining a complex mosaic of forest patches with smaller patches of high severity fire can help sustain California Spotted Owls in the greater landscape,” says Eyes. “What’s unique about our study is that we investigated fires that burned within the natural range of variation, so it paints a picture of how owls used a burned landscape before the onset of today’s large stand-replacing fires.” Despite the owls’ preference for edges, there may be a threshold over which edges have a negative effect on habitat quality, and more research is needed to find the right balance between beneficial edge habitat and potentially harmful habitat fragmentation.

    Stephanie A. Eyes, Susan L. RobertsMatthew D. JohnsonCalifornia Spotted Owl (Strix occidentalis occidentalis) habitat use patterns in a burned landscape. The Condor: Ornithological Applications, May 2017 DOI: 10.1650/CONDOR-16-184.1
  9. Changing climate could have devastating impacts on forest carbon storage

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    • mean loss of carbon from drought and fire impacted forests could equal losing 70% of CA’s 2010 total above ground biomass
    • strategies for reducing some fire risk include actively thinning forests to manage tree density and restoring surface fires
    • healthy ecosystems lead to cleaner, better regulated water flow to communities across the western United States
    May 25, 2017  University of New Mexico  full ScienceDaily article here
    Biologists have shown what could be a startling drop in the amount of carbon stored in the Sierra Nevada mountains due to projected climate change and wildfire events.

    ….roughly half of all human-emitted carbon is absorbed by vegetation and the ocean, and is stored through natural processes — something that helps limit our actual carbon impact on the atmosphere. The problem is, as forests begin to change, due to global warming and large scale fires, the amount of forest carbon uptake will decrease, accelerating the amount of human-made carbon making its way into the atmosphere.

    Our simulations in the Sierra Nevada show that the mean amount of carbon loss from the forests under these projections could be as large as 663 teragrams,” said Hurteau. “That’s equal to about 73 percent of the total above ground carbon stock estimated in California vegetation in 2010.”

    …The two factors that influence these findings are changes in climate and the likelihood of large scale forest fires. Because California is experiencing warmer and drier conditions due to global warming, certain tree species are not able to flourish across particular geographic regions like they once were. Less tree growth, means less carbon uptake in forests.

    The study also shows that wildfires will play a big role in the reduction of stored carbon. And while many of these incidents will occur naturally, Hurteau says we are, in part, to blame for their significance….

    …”We’ve been putting out fires for a hundred years, causing tree density to go way up. In the absence of fire that system has a lot more carbon stored in it,” explained Hurteau. “But, when you have these large fire events the amount of carbon stored in the system drops because it kills many of the trees. Whereas, in a forest that’s been maintained by regular forest fires, which is the natural ecological state, your total carbon at any given point in time can be lower but it stays more consistent.”

    …Hurteau says researchers have identified strategies for reducing some of the fire risk by actively thinning forests to manage tree density and restoring surface fires. It’s an idea that seems counterproductive until you consider how volatile these ecosystems are due to the risk of large scale fires that end up destroying hundreds of thousands of acres.

    …He says it’s not only for the benefit of nature but for all of us, since healthy ecosystems lead to cleaner, better regulated water flow to communities across the western United States.

    Shuang Liang, Matthew D. Hurteau, Anthony LeRoy Westerling. Potential decline in carbon carrying capacity under projected climate-wildfire interactions in the Sierra Nevada. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-02686-0