Forester Andy Cadenhead's first look at 2004 aerial survey maps showed some unexpected good news and some predicted bad news about the beetle infestations that have been leaving dead, red trees across Northwest Colorado.
The new maps offered the first signs that the area's spruce beetle infestation might be on the decline. Granted, the news comes after the beetles have more or less eaten themselves out of house and home, killing most mature spruce in the Routt National Forest and surrounding areas.
Unfortunately, the maps also showed that mountain pine beetles, which kill lodgepole pine, are multiplying rapidly, setting the stage for devastation to large tracks of mature pine across the county and Routt National Forest in the coming years.
"We're seeing a really dramatic increase, both in the
forest and in the county," U.S. Forest Service representative Cadenhead said about the mountain pine beetles.
In the past few years, there have been three-fold increases in mountain pine beetle populations. In 2004, land in Routt County that is outside the national forest boundaries showed a six-fold increase in the populations. In perfect conditions for the beetles, the bugs can multiply ten-fold each year.
"I think (the mountain pine beetle infestation) got a running start on us," Cadenhead said. "It's going to be difficult to put a stop to it."
On the incline, decline
Spruce and mountain pine beetles always are present in forests, but with the right conditions, their populations can explode, and the beetles then kill large tracts of trees quickly.
The population explosions happen in old trees and dense forest stands and require an environmental trigger. For spruce beetles, that trigger was the 4 million trees flattened in the 1997 Routt Divide Blowdown. For mountain pine beetles, that trigger has been recent dry, hot weather.
The epidemic ends when there is an extreme cold snap of 35 to 40 degrees below zero overnight while there is no snow on the ground -- or when the beetles consume all available trees. In the case of mountain pine beetles, a break in the drought could stop the growing populations.
A 2003 aerial survey showed that spruce beetles had killed an estimated 378,000 trees in the county and 514,000 trees in the Routt National Forest. In 2004, the same survey showed that beetles got to only 31,000 trees in the county and 67,000 trees in the forest, a fraction of what was infested the year before.
"There are hardly any trees left to eat," Cadenhead said.
It's too early to tell whether the beetles really are on the downswing, Cadenhead said, and there are still large tracts of spruce tree -- such as the Bears Ears and Black Mountain areas between Steamboat Springs and Craig -- where there is no beetle activity yet.
The tree death toll is highest in the Zirkel Wilderness and other areas in North Routt, where about 90 percent of the large spruce trees have been killed, Cadenhead said.
The mountain pine beetles, on the other hand, have shown a dramatic increase in population. The 2003 aerial survey showed an estimated 180,000 infected trees in the Routt National Forest and 22,000 infected trees in Routt County. Those numbers grew to 338,000 infected trees in the forest and 138,000 infected trees in the county in 2004.
The infestation has spread from 60,000 acres to 193,000 acres during a one-year period.
In 2004, the Forest Service tracked the beetle infestations on the ground for the first time and verified a roughly three-fold increase: For each dead tree counted, the Forest Service found about three infected trees. In the aerial surveys and on the ground, each dead, red tree counted represents a tree that was infected the year before.
This summer, effects on pine trees should be very noticeable north of Steamboat Lake in the Big Red Park, Little Red Park, Crane Park and Whiskey Park areas, Cadenhead said.
If dry, hot weather continues in the coming summers, the infestation will get worse.
The Steamboat Ski Area
The shift in beetle epidemics could bring good and bad news for the Steamboat Ski Area.
If the spruce beetles really have eaten themselves almost to death, and Forest Service and ski area workers continue to be able to hold most of the beetles one mile back from the ski area, then the spruce trees at the upper elevations of Mount Werner likely will survive.
In the late 1990s, ski area and Forest Service officials worried about whether they could prevent the spruce beetles from taking every tree on the top of the ski area, Cadenhead said.
"I don't know that anyone could have said with any confidence that we could," he said. Now, the Forest Service is holding its own ground, he said.
However, the mountain pine beetle populations inevitably will effect lodgepole pines at the ski area.
The pine trees are concentrated at the lower elevations, mostly from the top of Burgess Creek trail and even the top of the Rolex trail and down, said Lyn Halliday, director of environmental affairs for the Steamboat Ski and Resort Corp.
"There is a fair amount of infestation, and we have been working on prevention in those stands," Halliday said.
The Forest Service and the ski area have been working on reducing effects from the mountain pine beetles since at least 1999, Halliday said.
There are some dead trees at the ski area now, she said, but some that people are noticing are firs that have been hit by a fungus and beetle combination. That disease, however, does not have the explosive potential that the beetles do.
The largest tract of dead pine trees Halliday has heard of is along the Right-o-Way run, but some of those trees are on private property.
"We're trying to go at it each year and, cumulatively, hopefully, it will put a dent in it," Halliday said. "We have to be realistic, and pine beetles do occur naturally. ... so you'll never really get rid of it, nor should you have to."
Fortunately for the ski area, Halliday said, there is diversity in the tree stands, so even if a lot of one type of tree dies, many other trees would remain.
The Forest Service will continue most of its efforts to control the beetles, with some changes.
Its strategy to protect the most valuable areas -- including the ski area, campgrounds and the urban-forest interface -- remains.
The overall strategy, however, will shift gradually beginning this year, because the funding for dealing with the beetle infestations is dropping by more than half.
The Forest Service will move away from labor-intensive efforts -- such as cutting and peeling infected trees to prevent the bugs in those trees from spreading -- to using logging as a tool.
Through new rules, the Forest Service will be able to use funds from the sale of timber to pay logging companies to do some of those more intensive treatments, Cadenhead said.
That shift will be most obvious in the Rock Creek Integrated Management Project the Forest Service is proposing. In that project, which could be released for public comment in the next few weeks, as many as 15,000 acres of national forest and Bureau of Land Management land in South Routt County could be logged.
Eventually, logging could be used in North Routt County as well, Cadenhead said.
The Rock Creek project proposes spraying trees, some cutting and peeling and other beetle suppression efforts, and road work. The project covers an area from Lynx Pass to the Sarvis Creek Wilderness and Gore Pass, and south to the national forest boundary, including some BLM land.
When the draft environmental impact statement is released, the public will have 45 days to make comments under the new Healthy Forest Restoration Act.
If the plan works, it's likely to make a big difference in how many acres of pine trees get infested, Cadenhead said, and will ensure that chunks of forest stay green.
-- To reach Susan Cunningham, call 871-4203 or e-mail email@example.com