Plants that burn fastest in a wildfire

Lichen burns cool and quick, while spruce burns slow and hot.

 

This story is part of a package of coverage on wildfire in our recent print edition. See the feature story, 'After one record-setting wildfire, a Washington county prepares for more.'

It’s rare for the rainforest to catch fire; the Pacific Northwest’s old-growth forests are some of the wettest places in North America. But this year, the Olympic Peninsula saw its driest spring in over a century, and in late May, a bolt of lightning ignited the desiccated lichen and timber of the Queets River Drainage in Washington’s Olympic National Park.

Since then, the Paradise Fire has burned more than 1,600 acres, and fire officials expect it to continue until the end of summer. Much of the blaze has been spread by lichen, a composite symbiotic organism generally made up of fungus and algae. Lichen mantles the forest’s centuries-old Sitka spruce, western hemlock and Douglas-fir, forming ladders that flames easily crawl up. When those ladders collapse, fallen logs provide more fuel and intensify the fire. Lichen and mosses are unusual culprits. Typically, fires are driven by one of four vegetation groups — grass, shrub, slash or timber. But climate change and an altered fire cycle mean different fuel types are now carrying fires, and that makes it all the more urgent for scientists to understand each species.

Matt Jolly, at the Missoula Fire Sciences Laboratory in Montana, is one of the only researchers in the world attempting to model fire behavior after individual vegetation types. Instead of looking at a group, like timber, as a whole, Jolly examines the individual needles of a ponderosa pine. How quickly a plant ignites, and gets wet or dries, he explains, is directly related to its surface-area-to-volume ratio. “The fastest way to cook something is to flatten it out,” he says. “By flattening it out, you increase the surface area and therefore the contact with heat.”

That makes lichen, for example, incredibly flammable, far more than any other vegetation group. Moreover, unlike timber, which can take weeks to dry out, lichen can dehydrate in minutes. But just because lichen ignites quickly, doesn’t mean it causes the most intense fires. Very hot fires need a large volume of fuel, or vegetation, to sustain them. That makes timber the most dangerous vegetation group.

Although the Pacific Northwest’s forests are home to both lichen and massive stands of old-growth timber, fires there are typically restrained by other ambient factors, including rainfall. But as the drought persists and climate change alters humidity levels, rainforest fires could become more frequent. “It really depends what happens in the climate over the next 30 years,” Jolly says.

Click to view larger.
Sources: Matt Jolly, Missoula Fire Sciences Laboratory; James K. Brown, Ratios of Surface Area to Volume for Common Fuels, 1969.

Click to view larger.

Return to:

As wildfires get bigger, is there any way to be ready?
High Country News Classifieds
  • SOCIAL MEDIA AND DIGITAL ADVERTISING SPECIALIST
    The Southern Utah Wilderness Alliance (SUWA), Utah's largest conservation organization, has an immediate opening for a full-time Social Media and Digital Advertising Specialist. This position...
  • SPRING-FED PARCELS ON THE UPPER SAC RIVER
    Adjacent parcels above the Upper Sacramento river, near Dunsmuir. The smaller is just under 3 acres, with the larger at just under 15 acres. Multiple...
  • DEVELOPMENT COORDINATOR
    Greater Yellowstone Coalition seeks a development professional to coordinate the organization's individual giving program. The position description is available at http://greateryellowstone.org/careers Please email a letter...
  • IDAHO STATE DIRECTOR
    The Wilderness Society is seeking a full time Idaho State Director who will preferably be based in Boise, Idaho. At least 8-10 years of experience...
  • COMMUNICATIONS MANAGER AND BEARS EARS EDUCATION CENTER MANAGER
    Conservation nonprofit Friends of Cedar Mesa in Bluff, Utah is hiring for two positions. We seek a Communications Manager to execute inspiring and impactful communications...
  • EXECUTIVE DIRECTOR
    Wilderness Volunteers Wilderness Volunteers (WV), a 24-year leader in preserving our nation's wildlands, is seeking a motivated person with deep outdoor interests to guide our...
  • HECHO POLICY AND ADVOCACY MANAGER
    Hispanics Enjoying Camping, Hunting, and the Outdoors (HECHO) was created in 2013 to help fulfill our duty to conserve and protect our public lands for...
  • FISHERIES BIOLOGIST
    Under the direct supervision of the Director of Shoshone-Paiute Tribe's Fish, Wildlife & Parks, in coordination with the Tribal Programs Administrator and the Tribal Chairman,...
  • REGIONAL EXECUTIVE DIRECTOR NORTHERN ROCKIES, PRAIRIES & PACIFIC REGION
    Founded in 1936, the National Wildlife Federation has grown into America's largest and most trusted grassroots conservation organization with 53 state/territorial affiliates and more than...
  • STEWARDSHIP MANAGER
    STEWARDSHIP MANAGER Job Vacancy and Description Posted June 2, 2021: Open until filled The New Mexico Land Conservancy (NMLC) is a non-profit, regional land trust...
  • KSJD - MORNING EDITION HOST/REPORTER
    KSJD is seeking a host/reporter. Please see for www.ksjd.org for more information. EEO compliant.
  • ON THE EDGE OF CEDAR MESA/BEARS EARS
    Quiet, comfy house for rent in Bluff, Utah. Walk to San Juan River. Bike or hike to many nearby ruins and rock art sites. Beautiful...
  • CARPENTER AND LABORER WANTED.
    Come to Ketchikan and check out the Rain forest on the coast, Hike the shorelines, hug the big trees, watch deer in the muskeg meadows,...
  • PROJECT MANAGER
    Title: Project Manager Reports To: Program Director Salary Range: Negotiable; starting at $60,000 Location: Bend, OR The Deschutes River Conservancy seeks a Project Manager to...
  • PROGRAM DIRECTOR
    The Deschutes River Conservancy seeks a Program Director to join our dynamic team in restoring streamflow and improving water quality in the Deschutes Basin. WHO...
  • EXECUTIVE DIRECTOR - TWISPWORKS
    Established healthy nonprofit in the Methow Valley of Washington state, TwispWorks is hiring the next Executive Director. Terrific opportunity to strive for our mission to...
  • BOARD DIRECTOR
    Help us achieve our mission of promoting excellence in the professional practice of wilderness stewardship, science and education to ensure the life-sustaining benefits of wilderness....
  • TEMPORARY FULL-TIME RANCH OPERATIONS ASSISTANT
    Twin Willows Ranch in Ocate, NM is seeking to immediately fill a Temporary Full-Time employment position as Ranch Operations Assistant for Facilities, Equipment, Land, and...
  • RANCH OPERATIONS ASSISTANT
    Twin Willows Ranch in Ocate, NM is seeking an individual to fill the Regular Full-Time position of Resident Operations Assistant for Technology, Hospitality, Gardening, and...
  • POEM+ NEWSLETTER
    Start each month with a poem in your inbox by signing up for Taylor S. Winchell's monthly Poem+ Newsletter. No frills. No news. No politics....