The northern
spotted owl, a threatened species in the Pacific
Northwest, would actually benefit in the long run from
active management of the forest lands that form its
primary habitat and are increasingly vulnerable to
stand-replacing fire, researchers conclude in a recent
study.
Whatever
short-term drawbacks there may be from logging,
thinning, or other fuel reduction activities in areas
with high fire risk would be more than offset by
improved forest health and fire-resistance
characteristics, the scientists said, which allow more
spotted owl habitat to survive in later decades.
Decades of fire
suppression and a “hands-off” approach to management on
many public lands have created overcrowded forests that
bear little resemblance to their historic condition – at
the expense of some species such as the northern spotted
owl, researchers said.
The findings were
published in Forest Ecology and Management, a
professional journal, by researchers from Oregon State
University and Michigan State University.
“For many years
now, for species protection as well as other reasons,
we’ve avoided almost all management on many public
forest lands,” said John Bailey, an associate professor
in the Department of Forest Engineering, Resources and
Management at Oregon State University.
“The problem is
that fire doesn’t respect the boundaries we create for
wildlife protection,” Bailey said. “Given the current
condition of Pacific Northwest forests, the single
biggest threat facing spotted owls and other species is
probably stand-replacement wildfire.”
In the recent
project, scientists used computer models to compare what
would happen to vulnerable forest lands if they were
managed, or simply left alone. They found that over a
long-term period of about the next 75 years, active
management of sites with high fire hazard would be more
favorable for spotted owl conservation.
A “risk averse”
strategy in fire-prone landscapes is not the best
long-term alternative to conserve protected species,
they said.
As years go by,
forest conditions will continue to get even more
crowded, insect and disease epidemics will increase, and
forests will face stress from a warmer and often drier
climate. Fire levels will increase and the problem will
only get worse, Bailey said.
“Without active
management to reduce risks, we never really put fire
out, we just delay it,” he said. “We can keep kicking
the can down the road, but sooner or later a
stand-replacing fire will come that we can’t put out.
Then the fires are enormous.”
Historically,
Pacific Northwest forests, in both the wetter conditions
west of the Cascade Range and especially the drier
forests east of the mountains, were subject to higher
frequency of fire, fewer trees with less overall
biomass, and healthier forest conditions at a lower tree
density than today. Many fires did not climb into the
tree canopies and kill the tree, and even
stand-replacement fires were more limited in size and
scope.
A return to such
conditions would significantly change the shape of
modern forests, in the process producing more forest
products and perhaps nurture a biofuels industry. But it
would also result in less overall biomass and less
sequestration of carbon, a factor in global warming
concerns. The result, however, would be forests that
more closely resembled their historic status and
protected a wider range of species, including the
northern spotted owl, Bailey said.
This analysis
focused on fire-prone areas, the researchers said, and
they also noted that a broad commitment to such an
approach would be needed. Models suggested that more
than 20 percent of a fire-prone landscape would need to
be treated to begin altering fire behavior and reduce
loss of spotted owl habitat.