CURRENT POLICIES AND A CHANGING CLIMATE LEAD TOWARD
HIGHER COSTS, MORE SEVERE WILDFIRE
By Christopher Dicus,
Ph.D.
Fire is a natural part of
California’s forest ecosystems. Or is it?
Fire has historically
helped shape millions of acres of California forestland. But there is a vast
difference between high-intensity and low-intensity fire events; between what
Californians experience today and what European settlers encountered here.
California recently has
witnessed a dramatic increase in large, high-severity wildfires, which will
likely continue unabated unless steps are taken to address the unprecedented
fuel loads that clutter both public and private forestlands. This is a Herculean challenge given that more
than 8 million acres are at very high risk of severe wildfire, budgets continue
to be strained, and infrastructure to support fuel reduction efforts is in
decline.
Historically, frequent
low-intensity fires set by native people or lightning-strikes helped clear many
California forests of debris and prevented excessive fuel accumulations. These
fires moved slowly across the forest floor, burning pine needles, grass and
fallen branches. Flames generally one- to three-feet high had little effect on
mature trees, flaring up only occasionally to open small gaps, which helped to
regenerate forests and sustain them long-term.
High-intensity fires
such as the 2007 Angora Fire or the 2008 Uncles Complex can race through
treetops with 200-foot flames and scorching heat that destroys organic material
in soils, consumes seed-sources and can turn what was
once forests into vast shrub fields for decades. These fires can create their
own weather and propel embers a mile or more away, which start new “spot” fires
and thwart firefighter efforts.
Unnatural fire
A
century of aggressive fire suppression and decades of restricted timber
harvesting have resulted in an unnatural accumulation of fuels on many
California forestlands. Where 50-70 trees per acre stood before the Gold Rush, California
forests now average over 400 trees per acre. When fire enters these ecosystems the
resulting high-intensity wildfires are as unnatural as the accumulated fuels
that they consume.
Climate
change exacerbates the problem. Spring
thaws now come sooner, leaving forests without water for longer periods of time
and starting fire season earlier. Dryer conditions stress trees already facing
fierce competition for water and nutrients. Subsequently, more trees die and
forests become vulnerable tinderboxes.
Whereas
smoke from small, low-intensity fires tends to dissipate quickly, large
high-intensity wildfires can foul the air for weeks. Annually, wildfires in
California emit millions of tons of pollutants into the atmosphere, which can degrade
air quality for hundreds of miles. The particulate matter in smoke, often
smaller than 10 microns, is especially harmful to the health of children and
the elderly.
Efforts
to reduce fuel loads must consider economic and social realities. Ironically,
it often seems that well populated areas such as Cambria or Lake Tahoe, where
fuel-loads pose the greatest danger, provide the stiffest resistance to fuel-reduction
efforts. Residents placing a high value on forest aesthetics frequently object
to the smoke that can accompany prescribed burns (low-intensity fires
intentionally set under certain fuel-load and weather conditions) or the
thinning that could make the forests in which they live safer.
Prescribed
burns can offer a relatively low-cost means for reducing fuel loads, but many forestlands
are simply too overgrown to safely introduce any degree of fire. Where there is
significant risk of a prescribed burn morphing into the kind of high-intensity
wildfire that forest managers are aiming to prevent, areas must be mechanically
treated first, some trees cut and brush removed.
Economic relief?
Mechanical
thinning could potentially pay for itself, but instead is becoming more
expensive as the state’s forestry infrastructure slips further into decline.
Current regulations discourage harvesting of larger trees to be harvested
during fuel-reduction efforts. That should change, the value of harvesting a
few large trees could offset costs of thinning operations and increase the land
area that can be treated with existing dollars – provided there are still
sawmills to take the wood.
One-third
of California’s sawmills have closed in the last nine years, leaving many
forest managers with limited local infrastructure to help manage accumulated
fuels. The increased haul costs rapidly eat away available thinning funds, and
much-needed work goes unfunded and undone. The more infrastructure
we lose, the higher fuel-reduction costs we will incur.
At
present, Californians spend more than a billion dollars to fight wildfire
annually and relatively precious little to prevent it. It’s time for a more
balanced equation.
Given
the ecological impacts of large, high-intensity wildfire and the threat to
communities throughout California we should be doing more to reduce fuel loads
across the state. Policies that
encourage investment in forestry infrastructure and stretch fuel-reduction dollars
would pay Californians and their forests considerable dividends.
Christopher Dicus is a professor of fire and fuels management in the
natural resources management department at Cal Poly State University - San Luis
Obispo.