Smokey the Bear may have been steering us wrong for all these years, according to the following excerpt from COLLAPSE: How Societies Choose to Fail or Succeed, by Jared Diamond.
The U.S. Forest Service in the first decade of the 1900s
adopted a policy of fire suppression (attempting to put out forest fires) for
the obvious reasons that it didn't want valuable timber to go up in smoke, nor
people's homes and lives to be threatened. The Forest Service's announced goal
became, "Put out every forest fire by 10:00 A.M. on the morning after the day
when it is first reported." Firefighters became much more successful at
achieving that goal after World War II, thanks to the availability of
firefighting planes, an expanded road system for sending in fire trucks, and
improved firefighting technology. For a few decades after World War II, the
annual acreage burnt decreased by 80 percent.
That happy situation began to change in the 1980s, due to
the increasing frequency of large forest fires that were essentially impossible
to extinguish unless rain and low winds combined to help. People began to
realize that the U.S. federal government's fire suppression policy was
contributing to those big fires, and that natural fires caused by lightning had
previously played an important role in maintaining forest structure. ... Take
the [Montana's] Bitterroot low-altitude Ponderosa Pine forest as an example. Historical records, plus counts of annual tree rings and datable fire scars on
tree stumps, demonstrated that a Ponderosa Pine forest experiences a
lightning-lit fire about once a decade under natural conditions (i.e., before
fire suppression began around 1910 and became effective after 1945). The mature
Ponderosa trees have bark two inches thick and are relatively resistant to
fire, which instead burns out the understory of fire-sensitive Douglas Fir
seedlings that have grown up since the last fire. But after only a decade's
growth until the next fire, those seedlings are still too low for fire to
spread from them into the crowns. Hence the fire remains confined to the ground
and understory. As a result, many natural Ponderosa Pine forests have a
park-like appearance, with low fuel loads, big trees well spaced apart, and a
relatively clear understory.
Of course, though, loggers concentrated on removing those
big, old, valuable, fire-resistant Ponderosa Pines, while fire suppression for
decades let the understory fill up with Douglas Fir saplings that would in turn
become valuable when full-grown. Tree densities increased from 30 to 200 trees
per acre, the forest's fuel load increased by a factor of 6, and Congress
repeatedly failed to appropriate money to thin out the saplings. Another
human-related factor, sheep grazing in national forests, may also have played a
major role by reducing understory grasses that would otherwise have fueled
frequent low-intensity fires. When a fire finally does start in a
sapling-choked forest, whether due to lightning or human carelessness or
(regrettably often) intentional arson, the dense, tall saplings may become a
ladder that allows the fire to jump into the crowns. The outcome is sometimes
an unstoppable inferno in which flames shoot 400 feet into the air, leap from
crown to crown across wide gaps, reach temperatures of 2,000 degrees
Fahrenheit, kill the tree seed bank in the soil, and may be followed by
mudslides and mass erosion.
Foresters now identify the biggest problem in managing
western forests is what to do with those increased fuel loads that built up
during the previous half-century of effective fire suppression. In the wetter
eastern U.S., dead trees rot away more quickly than in the drier West, where
more dead trees persist like giant matchsticks. In an ideal world, the Forest
Service would manage and restore the forests, thin them out, and remove the
dense understory by cutting or by controlled small fires. But that would cost
over a thousand dollars per acre for the one hundred million acres of western
U.S. forests, or a total of about $100 billion. No politician or voter wants to
spend that kind of money. Even if the cost were lower, much of the public would
be suspicious of such a proposal as just an excuse for resuming logging of
their beautiful forest. Instead of a regular program of expenditures for
maintaining our western forests in a less fire-susceptible condition, the
federal government tolerates flammable forests and is forced to spend money
unpredictably whenever a firefighting emergency arises: e.g., about $1.6
billion to fight the summer 2000 forest fires that burned 10,000 square miles.
* * * * * * *
Truth is...it shouldn't surprise anyone that we cause quite a mess when we mess with God's original arrangement.
