Montrose - Daily Press

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.

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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 landscape.

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 too slow.

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 of Montrose.

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 the West.

"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" concept.

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 centuries."

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 Plateau.

"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 said.

"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 the infestation.

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 said.

"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 Research.

The scientists' argument has garnered mixed responses from forest-health experts.

"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."

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, Cross said.

"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 material."

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 activities."

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 the barn."

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."

Contact Russell Smyth via e-mail at russells@montrosepress.com.

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