7. Graduate research

Understanding fire as an essential process for maintaining biodiversity
by David Zubenko

Most people instinctively move away from fire.  Ph.D. student Catherine Airey is trying to move closer to it.

     Specifically, Airey is investigating how fire affected the Sawtooth Mountains in Idaho before Euro-American settlement (around 1850) and how and when this settlement changed the area into what it is today.  To do this, she examines fire scars in living trees and dead stumps, “to find out how often fires burned, at what time of year, and during what kind of climate pattern.”  Ultimately Airey hopes the knowledge she gains, “will support decision makers in identifying and achieving restoration goals and preparing for climate change while minimizing costly inaction and destructive mistakes.” This work is supported logistically and financially by the Fairfield Ranger District of the Sawtooth National Forest.

A fire-scarred Douglas-fir






A fire-scarred Douglas-fir tree in the Sawtooth National Forest.

Photo by Catherine Airey.










     Airey’s journey toward fire research began with a B.A. in Biological Sciences from Northwestern and an M.S. in Ecology from Penn State.  Along the way she had an internship at Avon Park Air Force Range in Florida that is home to fire-dependent plant and bird species.  As Airey notes, “The species thrive there due to [the] frequent fires accidentally ignited by training missions in the past and continued today by an active prescribed burn program.”  Eventually she migrated to Yosemite National Park and worked with fire ecologists and managers to reverse the region’s history of fire suppression.  The contrast between these two experiences led Airey to her current research, which has its own challenges and difficulties. 
     “There is urgency because long-unburned forests can become increasingly susceptible to destruction in severe fires,” she says, adding, “With increasing time since fire, it becomes more difficult to interpret how the burned forests once looked and how fire functioned in the ecosystem.  It becomes more difficult to reintroduce fire in a desirable way.  And none of that begins to address concerns about increasingly severe droughts and weather patterns that are predicted to occur as a result of climate change.”

 Despite its reputation, fire can actually be beneficial or even necessary.  The Nature Conservancy estimates that about half of terrestrial earth is covered by fire-dependent ecosystems, defined as “ecosystems where most species evolved in the presence of fire, and where fire is an essential process for conserving biodiversity.” 
     Airey explains that a variety of species, including the majestic sequoia, rely on fire to eliminate competition and burn off surface litter.  Others have developed characteristics in response to the flames, such as thick bark, serontinous cones, heat-germinated seeds, and high branches. In addition, many low-lying plants sprout and thrive after fire has cleared the dense underbrush from the surface.  Forests that contain this type of diversity need periodic cleansings to maintain the overall health of the ecosystem.  This is where fire can come in as an important and necessary tool for preserving the natural balance of our world.
     Over the past several years this balance has increasingly been affected by the Wildland-Urban Interface, or WUI.  Basically, the WUI is the boundary between nature and the built environment.  This boundary is increasingly intruding into forests and other wildlife areas, and the push outward has generated a variety of problems.  As Airey notes:
     “The Wildland-Urban Interface, WUI, is a big, expensive, and sometimes dangerous problem that is only increasing with development.  Protecting homes during wildfires is very costly. People who choose to live in fire prone areas should take steps to equip their residences accordingly. These steps include things like fire resistant roofing materials and properly maintained landscaping that is removed from the house.”
     Ultimately the issue of WUI helps illustrate what drew Airey to fire research in the first place, and why it’s so important: “Simply preserving land is not enough to preserve species diversity. It is important to also preserve or mimic the processes that maintained the biodiversity.” 
    Fire is one of those processes, and by studying it Airey hopes to learn how our past and present can influence our future.  Along the way she is trying to learn the best way to manage this dangerous but beautiful force of nature.