|
For
example, the mean fire interval in many Western
ponderosa pine forests is 10-20 years, sometimes even
less. But the standard deviation may be as much as
50-60 years. In other words there are some periods
when no fires occurred for a half-century. This is in
effect no different from the length of time we have
had effective fire suppression. This suggests that the
idea that there are currently abnormal fuel loadings
may be inaccurate or at least an exaggeration. In
other forest types, particularly those at higher
elevations, the disparity between the mean fire
interval and the longest intervals between blazes is
even greater, effectively negating any effect of fire
suppression in these ecosystems.
Furthermore,
fire-scar histories are not necessarily the best
indicator of long-term fire records. If you look at
longer temporal and spatial dimensions, you often find
that past climatic conditions created situations not
much different from today's conditions. Charcoal and
pollen studies provide a much longer climatic and fire
record than fire scars, and demonstrate that in the
past there have been wetter periods with few fires,
when fuels grew, followed by drier periods when large
widespread blazes were the norm. For example, in the
mid-elevation mixed conifer forests of the Sierra
Nevada, there was an extensive period between
1100-1400 when drought was prolonged. This is the same
time period that the Pueblo Indians abandoned many of
their Southwestern sites. Large blazes that burned
across much of the Sierra Nevada Range occurred during
this long drought period. At other times, moist, cool
weather created conditions that in many respects did
not differ much from the current situation under fire
suppression, with few fires.
Regardless
of fuel loading, what drives big blazes aren't fuels.
It would be difficult to argue that there was
significantly more fuel in the forests of Yellowstone
in 1988 than in 1987. So why did hundreds of thousands
of acres burn in 1988 and not in 1987 or 1986? The
reason has to do with fire behavior and spread.
There
are certain conditions that create large blazes.
Extended drought. Low humidity. High winds. Without
all of these you won't get a big fire - even if there
is a lot of fuel. It's not fuels, ultimately, that
creates large fires, but these other factors. It's
somewhat analogous to driving a car. Just because
there's gas in the car, doesn't mean it will go
anywhere. You need to simultaneously turn on the
ignition, step on the gas, and let out the clutch, or
the car won't move forward.
Extended
drought and high winds characterize all big fires.
Fighting fires under these conditions is a waste of
time and money. Winds carry burning embers a mile or
more ahead of the fire front. Winds carry flames
through the crowns of trees. Low humidity means fires
don't die down at night, as is the case under less
extreme conditions. In every instance where there have
been large fires, the only thing that put them out was
a change in the weather, not the efforts of
firefighters. It will rain or snow and the fires will
be "controlled," but what isn't acknowledged
by firefighters is that most of these fires would go
out on their own anyway.
There
are certain conditions that create large blazes. Extended
drought. Low humidity. High winds. Without all of these you
won't get a big fire - even if there is a lot of fuel. It's
not fuels, ultimately, that creates large fires, but these
other factors. It's somewhat analogous to driving a car.
Just because there's gas in the car, doesn't mean it will go
anywhere. You need to simultaneously turn on the ignition,
step on the gas, and let out the clutch, or the car won't
move forward.
Extended
drought and high winds characterize all big fires. Fighting
fires under these conditions is a waste of time and money.
Winds carry burning embers a mile or more ahead of the fire
front. Winds carry flames through the crowns of trees. Low
humidity means fires don't die down at night, as is the case
under less extreme conditions. In every instance where there
have been large fires, the only thing that put them out was
a change in the weather, not the efforts of firefighters. It
will rain or snow and the fires will be
"controlled," but what isn't acknowledged by
firefighters is that most of these fires would go out on
their own anyway.
A
passage from a firefighter's journal written in the 1930s
illustrates this point. "Finally got the fire under
control today. Had a hell of a time breaking camp in the
rain."
The
fact that this summer's blazes went through regrowing
clearcuts and thinned forests alike demonstrates that
reduction of fuels doesn't matter when drought and wind are
combined into an unstoppable force. Indeed, there is some
evidence to suggest that logging can actually exacerbate
fire spread under these conditions. Young regrowing trees
have a large crown-to-root ratio. With a small root system,
and a high demand created by many needles, small trees dry
out sooner than larger trees. But a dry green tree is even
more explosively flammable than a dead tree. Dry green trees
still have volatile resins in them, and they burn very well
if ignited. But this only happens under extreme drought
conditions. Under anything less than extreme drought, the
trees are too green to burn.
Even
thinned forests may not prevent big blazes. Thinned forests
dry out sooner, making them more likely to burn. Plus wind
can drive flames farther through a thinned forest than in a
dense unlogged stand, helping to spread crown fires. Again
this only happens under extreme conditions. Under less than
extreme conditions, a thinned forest might appear to
fireproof a site, giving one a false sense of security.
There
are reasons why we should not want to reduce the intensity
or spread of large fires any more than we should be trying
to eliminate 100-year floods. The low intensity small fires
that are relatively common in most forest ecosystems are
like the annual spring flood on most rivers. They are
predictable, and low intensity. While important, they are
not the events that really shape a river's channel and flood
plain. It is the 100-year flood that does most of the
ecologically important work of shaping rivers and their
channels. Big blazes are like the 100-year floods, and they
are really the only ecologically significant fires.
There
are reasons why logging may be far worse for the forest than
the fires themselves.
Just
as the real lasting impact of a nuclear bomb is not the area
directly destroyed by the bomb, but all the radioactive
fallout that affects a far larger area, logging creates a
lot of collateral damage. Most logging in the West requires
roads. Roads are one of the biggest sources of sedimentation
that directly impacts rivers and fisheries. While sediment
rates can be high after a blaze, within a few years, the
sedimentation usually returns to pre-fire levels. On the
other hand, logging roads remain in use for years, if not
decades, and continue to be a source of sedimentation and
slope failure.
Roads
are also a major vector for the spread of exotic weeds and
other species. The establishment of weeds is a long-term
threat to any ecosystem, and logging roads facilitate this
spread.
Logging
roads also increase access for hunters, trappers, and
poachers, affecting the distribution, age structure and
numbers of target species. Logging also removes the woody
debris and snags that would otherwise provide home for many
wildlife species, from cavity-nesting birds to ants.
Even
the charred snags remaining after a fire provide some shade
and hasten the establishment of new tree seedlings. And when
these snags fall into streams they provide a long-term
source for fish habitat and bank stabilization material.
Another
problem with forest manipulation is how it affects natural
processes. Just as hunters don't select the same animals
that other native predators kill, logging never emulates
natural selection. No matter how we attempt to thin a
forest, we won't be taking out the trees that would be
killed by nature. How human manipulation will affect the
long-term health and genetic diversity of a forest is seldom
discussed, but it could have serious consequences.
Finally,
even if fuel reductions worked, and even if foresters
somehow were so smart they could effectively emulate natural
selection in terms of the age, condition and size of trees
removed, to really make any kind of ecologically significant
difference in fireproofing our forests would require
treating hundreds of millions of acres. Not only would this
be prohibitively expensive, but it would take decades. Long
before you could treat all the forests that one deemed in
need of fuel reductions, new fuels will have accumulated in
the areas treated early on in the project, negating any real
effect.
What's
needed is for us to stand out of the way. Let the forest
burn. I know of many species endangered due to logging and
its aftermath, but I know of no species endangered by large
blazes. Forests and wildlife have been dealing with periodic
large blazes for thousands of years. If fuels are too high,
a number of good fire summers will change that. We must quit
suppressing fires, logging forests, and overgrazing
grasslands. With big blazes, we can let natural processes
reset the ecological clock.
In
reality, rather than a disaster or a catastrophe, the summer
of 2000 was one of the best years in a long time.
George
Wuerthner is a freelance ecologist, photographer and writer
who has written 24 books, including one
dealing
with wildfires and another on the Grand Canyon.
The
Southwest Forest Alliance and the Flagstaff Activist Network
are offering field trips to Fort Valley Restoration sites.
The field trips will include a tour of the Fort Valley
restoration logging project demonstration sites and a
presentation/discussion of FAN and SWFA's concerns about the
"presettlement" restoration model. If you're
curious about the "Flagstaff Plan" and
environmental groups' objections to it, this trip is
designed to answer your questions and show the "presettlement"
model on the ground.
Interested
people can call Roxane at 774-6542 or 774-6514 for more
information and to schedule a field trip. There is no charge
to participate.
The
U.S. Forest service has a self-guided auto tour of the
Kendrick Peak Pumpkin Fire. Brochures are available at the
Pumpkin Trail trail head parking lot.
If you value writings like
this, please support Flagstaff Tea Party with a
tax-deductible donation! Flagstaff Tea Party depends on the
generous financial support of people just like you to
continue its important work. With your donation of $35 or
more, ($20 for low-income individuals), you will become a
member of Flagstaff Tea Party. As a member, you will be
entitled to various benefits, such as discounts on
advertising, and delivery of FTP by mail, if you wish. But
best of all, you will enjoy the satisfaction of knowing that
you are supporting a worthwhile endeavor. Without your
support, FTP would be just another advertiser-driven rag,
with nothing to offer except blandness and business-as-usual
rhetoric. We know you wouldn’t want that!
Flagstaff Tea Party
P.O. Box 22324
Flagstaff, AZ 86002
Ph: (928) 774-5942
Fax: (928) 222-0153
Advertising: (928) 606-7186
E-mail: ftp (at) flagteaparty (dot) org
www.flagteaparty.org
|
