Bark beetles and "Healthy Forests" (long)
lhfotoware at hotmail.com
Tue Mar 9 09:41:30 EST 2004
March 7, 2004 Montrose Daily Press
'Healthy forest' fears ignite as die-back kills millions of trees
by Russell Smyth
MONTROSE - A massive die-back killing tens of millions of trees in
Western states has ignited debate over public-land management and the
term "healthy forests."
Drought and insects have swept through woodlands across thousands of
square miles, leaving forests of dead-standing timber that many
officials fear could explode into catastrophic wildfires.
After wildland blazes ravaged more than 1 million acres, destroyed at
least 3,600 homes and killed 22 people in California last fire season,
the forest health message seemed simple: Dead brush and trees increase
the risk of a catastrophic wildfires, so cut dead woody material from
The U.S. Department of Agriculture and U.S. Department of the Interior
released a 56-page guide Wednesday that shows public-land managers how
they can expedite tree thinning and other projects designed to lessen
wildfire risks. Called "The Healthy Forests Initiative and Healthy
Forests Restoration Act Interim Field Guide," the document will help
implement plans the Bush administration and U.S. Rep. Scott McInnis,
R-Grand Junction, developed. The guide claims environmental reviews
created to protect landscapes actually hamper federal agencies'
ability to implement wildfire-reduction plans because the reviews are
A group of 13 forest-health experts, however, claims solutions to the
die-back that has hit Western forests are not as clear as simply
removing trees from public lands. Members of the group recently
co-signed a letter to U.S. Department of Agriculture Secretary Ann
Veneman and U.S. Department of Interior Secretary Gale Norton that
challenges some popular beliefs regarding forest health and wildfires.
"There's never been a real rigorous test of the effects of dead trees
on subsequent fire behavior," said Bill Romme, a Colorado State
University professor of fire ecology who co-signed the letter.
"There's just the assumption that because there's all that dead wood
the fires will be more severe. That may be true in some situations,
and we (who signed the letter) acknowledge that, but we doubt it's
true in all situations."
The group of forest-health experts is not an official organization or
government entity. Members comprise scientists based in Colorado,
Arizona, Utah, New Mexico and California. Romme and another of the
letter's co-signers, Peter Brown, a dendrochronologist with Rocky
Mountain Tree Ring Research Inc. in Fort Collins, have studied
woodland conditions on the 2,290-square-mile Uncompahgre Plateau west
Although addressed to secretaries of the agriculture and interior
departments, which oversee the U.S. Forest Service, U.S. Bureau of
Land Management and National Park Service, the group of scientists'
letter has circulated among many forest-health officials throughout
"Primarily it was to inform them, but I guess we were hoping to get a
response - or at least an acknowledgement," Romme said. "We haven't."
They will, however. The Forest Service is preparing a response, said
Frank Cross, forest health group leader for the Forest Service's Rocky
Mountain Region, which oversees national forests and grasslands in
five states, including Colorado.
Scientists and Forest Service officials aren't the only people
responding to the extensive die-back in Western forests. State and
federal land managers, timber industry officials, environmentalists,
wildland firefighters, county commissioners and U.S. congressional
delegates have debated how they should respond to dying woodlands.
The 'perfect storm'
Forest-health experts agree on one thing: A combination of climate and
insects created the die-back in Western forests.
The letter Romme co-authored describes a "perfect storm" of mortality
that has covered thousands of square miles of pinyon pine, ponderosa
pine and other forest types in Colorado, New Mexico, Arizona and Utah.
Focusing more on pinyon pines and on the Southwest, the paper points
to unusually wet conditions prior to the recent drought. For instance,
tree-ring reconstructions of climate in New Mexico indicate the
20-year period from 1976 to 1995 was the third wettest in the past 750
to 1,000 years. During this wet period, forests grew denser.
Severe drought following the wet period desiccated forests, which had
grown relatively dense and needed more water than they normally would
require. Drought killed some trees and weakened others.
A third climatic condition, unusually warm temperatures during the
past decade, helped tree-boring insects thrive. Aided by warm shoulder
seasons, beetles whose larvae feed on pinyon pine bark, mature then
fly to other trees have increased their life cycles from two
generations per season to as many as four.
Another meteorological phenomenon, global warming, should be
considered when forest-health officials consider the life cycles of
tree boring insects and their impacts on Western forests, said Brown
of Rocky Mountain Tree Ring Research.
"The issue right now is if global warming is occurring," Brown said.
"If that is affecting temperatures, how is that affecting insects?"
Cross of the Forest Service said he agrees with the "perfect storm"
Tim Garvey, a silviculturist with the Forest Service's Norwood and
Ouray ranger districts, compared the die-back to a tornado of a
magnitude that people would only see once every 400 years. He also
said the die-back could be compared to a 500-year flood.
"This isn't a maintenance type of disturbance," Garvey said about the
Forest Service's ability to respond to the die-back. "It's resetting
the clock, which doesn't happen very frequently."
Although they may be rare, large-scale die-backs such as the one
sweeping through Western forests are not unprecedented, Brown said.
The scientific community is still trying to learn the historic cycle
of large-scale woodland die-backs, Romme said.
"I think we can say pinyon mortality of this magnitude has not been
seen in the past 100 years," he said, referring to one species the
die-back has hit hard, "but we don't know whether this kind of
mortality is precedented at longer time scales, perhaps of many
Released in January, the state of Colorado's "2003 Report on the
Health of Colorado's Forests" estimates one subspecies of bark beetle,
Ips confusus, has killed 1 million trees in the Centennial State.
Aerial surveys the Forest Service conducted in 2003 estimate 4.2
million pinyon pine trees have died across 937,000 acres of public and
private lands in Colorado, which has more than 4 million acres of
pinyon pine stands. The pinyon die-back has hit areas around Durango,
Cortez and Dolores the hardest.
In addition to aerial surveys, Forest Service officials used study
plots to conduct on-the-ground estimates of pinyon pine mortality,
said Roy Mask, a Gunnison-based entomologist with the Forest Service's
Rocky Mountain Region. Sixty plots located on federal lands in
Colorado showed a 27 percent overall mortality in pinyon stands.
Mortality rates ranged from 0.0 percent to 100 percent.
Mask emphasized the study plot results are preliminary. Overall pinyon
pine mortality rates for plot samples in other states follow: New
Mexico, 15 percent; Arizona, 27 percent; California, 15 percent; and
Utah, 3 percent.
The pinyon pine die-back has swept into some areas near Montrose,
Garvey said. He described dead and dying trees on the Uncompahgre
"It's apparent there is increased mortality," he said. "You know if
you drive up - and it seems to be in the lower elevations - up the
Delta-Nucla road (Mesa Road), Transfer Road, even Dave Wood Road - you
drive up any of those roads out of town and it's very obvious."
Although the group of scientists' letter focuses on pinyon pines,
Romme said he would not want to assert that one species is suffering a
greater die-back than other trees in Western states.
"Depending on where you are, different tree species are getting hit
the hardest," he said. "In central Arizona, the ponderosa pine is
getting hit very hard. In southern Utah, the Engelmann spruce is
getting really hit. Throughout the West, almost all the major tree
species are getting hit hard somewhere."
Bark beetles are boring into pinyon pines, ponderosa pines and other
species, Cross said.
"The beetle activity is up all over the place in all species of trees
and in almost all bark beetles. I think it's a result of drought
primarily and forest conditions secondarily," he said, referring to
stands of overly dense, older trees.
Forest Service officials are concerned about Engelmann spruce, Cross
"I think right now we're at the beginning stages of, if it continues
growing, a huge spruce beetle (infestation). Š It doesn't happen
very often, maybe every 150 to 200 years, so we don't know very much
about the spruce beetle."
An infestation that started in the late 1930s and ran through the
early 1950s killed an estimated 250,000 acres of spruce trees in the
Flat Tops area north of Glenwood Springs, Cross said. Eventually, a
combination of extreme cold and predators such as woodpeckers checked
Closer to Montrose, beetles have hit Engelmann spruce on the
Uncompahgre Plateau, and on portions of the Grand Mesa and the
Cimarron River Basin, Mask said.
Ponderosa pine trees have not escaped the die-back, either, Cross
"It's not doing well, either," he said about the species. "There's a
huge epidemic that's kind of winding down now in the Arkansas Valley.
Š It's killed thousands of acres of trees in that area. It's
pretty much killed all the trees it's going to right now I think."
Combinations of drought, bark beetles and disease have affected
subalpine fir in forests near Montrose, Garvey said. However, he said
the extent is not "striking."
"We're being watchful," he said. "We're monitoring."
Prescriptions for a 'healthy forest'
Although forest-health experts agree that climate and insects have
created the massive die-back in Western forests, deciding how to
manage tens of millions of dead trees has sparked some debate.
The group of scientists' letter, for instance, contends the risk of
catastrophic wildfires will eventually decrease in stands of dead
pinyon pine trees.
"Conventional wisdom is that when you have a lot of dead trees you
increase the fire hazard, but that conventional wisdom may not always
be correct," Romme said. "Our group wants to challenge fire managers
to really evaluate whether that assumption is correct, and in the
pinyon/juniper system we think it probably is not."
Wildfire risks will increase in pinyon pine trees for about one year
while the trees retain their dead, highly flammable leaves, according
to the letter Romme co-authored. In pinyon pine stands, crown fires,
which burn through the crowns, or tops, of trees, primarily consume
needles and small twigs, not the larger branches, the letter contends.
Additionally, moisture-stressed live needles may burn more intensely
because they have flammable terpene compounds. Consequently, after the
needles fall from dead trees, the risk of a crown fire blazing through
pinyon pine stands will decrease.
Instead of following the conventional wisdom of removing dead trees to
reduce wildfire hazards, the letter asks federal land managers to
reconsider plans to use either small, prescribed fires or mechanical
treatments to clear pinyon/juniper stands. The treatments could have
negative effects, including soil erosion and the spread of cheatgrass,
a nonnative species that crowds out native plants and elevates the
risk of frequent ground fires.
"One of the issues that I think is going to come up very soon is what
we're going to do with the dead trees out there. Š Managers are
going to feel the need to do something. Our basic contention is,
'Well, let's wait and see,'" said Brown of Rocky Mountain Tree Ring
The scientists' argument has garnered mixed responses from
"I think they're pretty accurate with their assessment of the fire
behavior," said Dan Huisjen, a Bureau of Land Management fire
ecologist based in Montrose. "The component that's going to carry a
fire through a pinyon/juniper stand is the needles. The drier the
needles are, the more intense and faster a fire will be. So when the
beetle hits them and the needles turn red, there is some very
significant fire danger while the needles are on the tree. But once
those needles fall on the ground, within six months to a year most of
the carrier for the fire is no longer present for that intense crown
Fire danger may decrease for some time after dead pinyon pine trees
drop their needles, but the scientists may have overstated the
long-term reduction in fire danger, said Cross of the Forest Service.
"In the long term I think it's a huge question mark," he said.
"There's going to be all these dead trees falling to the ground, and
there's going to be something to replace them. And whatever replaces
them, it seems to me, is going to replace the fire behavior. Š
That paper I think was stretching out there when they said there's
going to be a big impact on fire."
Land managers need to treat some woodlands the die-back has affected,
"There's small areas like in urban interface areas and recreation
areas and areas of high interest where we feel we do have a positive
motivation to do something about the epidemic," he said. "In many
cases it's just going to be restoration, trying to get rid of the dead
Wildfire officials should decide what management practices will work
most effectively for a particular woodland instead of adopting a
broad-brushed approach to the die-back, Huisjen said.
"The paper points out the need to be cautious in going into some of
these impacted areas, and I agree with that," he said. "But we need to
look at it on a case-by-case basis. In some areas we may want to go
in, have the public go in and salvage the fuels for firewood. In some
other places we may want to do some additional fuels treatments, but
we need to take a cautious approach with those post-insect-epidemic
Land managers' responses to the scientists' letter have been
"generally favorable," Romme said.
"There's been concern we were trying to curtail managers' options with
the dead trees, and we clarified that's not what we had in mind at
all," he said. "We wanted to suggest additional options they could
chose from, but the local managers and the public are the ones who
should make the final decisions."
It's too early for the Forest Service to determine how it will respond
if the die-back in area woodlands surrounding Montrose becomes too
severe, Garvey said. Forest Service officials have not worked with
this type of large-scale die-back, so it is a new experience for them.
One consideration is whether logging companies can salvage dead trees.
Another is how flammable the dead trees might become.
The die-back is too massive to contain, said John Moore, a planner
with the National Fire Plan assigned to the Grand Mesa, Uncompahgre
and Gunnison national forests.
"When you're in an epidemic situation, trying to do something on a
landscape scale is not practical or feasible," said Moore, who is
based at the GMUG headquarters in Delta. "The horse is already out of
However, Forest Service officials can study ways to manage woodlands
so they will be more resilient to future large-scale die-backs, Moore
said. For instance, the agency has managed stands of ponderosa pine so
the trees will be about the same age. Although this technique improves
tree harvesting, it makes the ponderosas more susceptible to insects.
Uneven-age stands distributed in clumps across the landscape are more
natural and more resilient.
The Forest Service may want to treat some dying pinyon pine woodlands
in wildland urban interface (WUI) areas to reduce the risk of
wildfires burning structures, but generally, the agency will let the
beetle epidemic run its course, Moore said.
"It's very hard to chase bugs," he said.
Generally, the die-back also will run its course in other species such
as ponderosa pine, fir and spruce, Moore said. The Forest Service will
study management options in WUIs. Outside the WUIs, the agency will
consider protecting some "high value" areas such as campgrounds.
As forest-health officials continue to address the massive die-back in
Western forests, they will grapple differences between Mother Nature
and humans, Cross said.
"I think that what we are seeing are natural events for the most
part," he said. "Where they become problems is where we have
objectives that interfere with these events. What I mean by that is we
have a lot of uses of our forests that conflict with a lot of the
large-scale disturbances we're seeing, including Š housing,
recreation, developments, ski areas, threatened and endangered species
habitat, and areas where we want to grow trees for timber production -
and the list goes on. It's in those areas where we find conflict. But
ecology - this is the way nature does things."
Comment from poster: It was inevitable that all these elements came
into play at the same time in our forests. Did it take a disaster of
this magnitude to convince Americans that their National Forests were
indeed in danger? YES! Anything less would've had preservationist
groups pushing the idea that this is all natural. Even without
references, anyone can see that, in many places, there are too many
trees for the amount of available water. How many times do we have to
deal with forests crises before we start to treat the disease instead
of the symptoms?
Larry, posting the truth about our forests
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