« Previous Story |
The Industry Report Home Page
| Next Story »
An IR In-Depth Report Beetlemania Returns, But Is Decidedly Unwelcome
By Roger Leo
August 11, 2008
Mountain pine beetles, an endemic native insect that inhabits the Rocky Mountains, are at epidemic levels in vast areas of North American forest, particularly in Colorado, Montana, parts of Utah, and much of British Columbia. But, is the impact more economical than ecological?
"The whole range of the mountain pine beetle, from Mexico to Canada, is under outbreak," Allan Carroll, an insect ecologist with the Canadian Forest Service in Victoria, B.C. told The Industry Report.
"British Columbia is undergoing the biggest outbreak to date in any part of the mountain beetle range since the 1990s. The area affected is now roughly 36 million acres, about the size of Nepal, or one-and-a-half times as big as Maine or Indiana," Carroll said.
British Columbia is about 248 million acres in size, with about half that working forest. Carroll said mountain pine beetles like mature pine trees of all species.
The North American outbreak began about 10 years ago, and is projected to continue for another six years.
"Our predictions are that at the end of this outbreak, which will last another four to six years, we expect to lose 80 percent of our mature pine in British Columbia," he said.
Medium-range prognosis in areas hardest hit by the beetles is for a changed mix of trees, along with significant economic impacts on ski areas that have had to manage large numbers of dead or dying trees, severe disruption in the forest products industry, some effects on biodiversity, and uncertain long-term impacts on drinking water supplies and fisheries through changes in watershed hydrology.
Winter Park Resort, 67 miles west of Denver, is at the center of one epidemic outbreak of mountain pine beetles.
Doug Laraby, Winter Park's Mountain Planner, said the current pine beetle eruption began in 2004.
"It really hasn't affected winter operations. It has affected maintenance in summer, mainly in the form of cutting down trees," Laraby said.
He said Winter Park operates on public land managed by the U.S. Forest Service, and the resort works closely with the service in implementing a vegetation management plan.
The venerable resort encompasses about 4,000 acres, 1,000 of them covered by lodgepole pines, one of several pine tree species susceptible to the mountain pine beetle. Of those 1,000 acres, 200 acres contain lodgepole pines that are not susceptible because they are younger trees in areas logged in the 1950s and 1960s.
"If they hadn't done that logging, those trees would have died or be dying," Laraby said.
Management involves logging in affected areas to remove dead or dying trees, and thinning stands that have not been hit.
"What we're doing now is logging these areas, doing regeneration cuts. We remove all mature lodgepole pine that are either dead or going to die, and leave younger trees standing.
"We don't have to plant or seed these areas. The trees will start to regenerate on their own, hopefully in two or three years.
"Tree islands are very important for skiing. They protect trails from wind, and they delineate trails," Laraby said." Then there's all the other things tree islands do: water quality, wildlife, wetlands, visual quality, and so forth."
The summer forestry work to manage mountain pine beetle damage is expensive.
Winter Park will spend $300,000 this year. The resort spent $550,000 in 2005 for major thinning of one out of every three trees on the Mary Jane side of the mountain, which is steep and rocky and required the use of helicopters.
"It's costing us $1,500 to $2,000 an acre to do regeneration cutting," Laraby said. Winter Park was not spending any of that money five years ago.
Robert Mangold, Forest Health Protection Director with the U.S. Forest Service, told the IR, "Mountain pine beetles get epidemic from time to time, and this is one of those times. Their impacts are quite large right now, including impacts at ski areas. We're not going to stop these epidemics, but we're going to try and protect some property and people's homes and some resources in highly prioritized places where it's really important, and ski areas are among those places."
Mangold said the age of the forest and its homogeneity favor the beetles.
"They're endemic; that is, they're always there, but they're at a real low level. This particular epidemic will burn itself out over the next couple years, but we'll have, over a longer period, other areas where the beetles will become epidemic. They can't stay epidemic very long in one particular area," he added.
Bark beetles include 20 different species, with the mountain pine beetle the most important one, Mangold explained, accounting for about two-thirds of all bark beetle activity in the West.
He said the United States has 740 million acres of forest, some hundreds of millions of acres in the West, with six million acres of forest in the West suffering mortality from various western bark beetles in 2007.
"Lodgepole pine is a big forest type, and a host preference for mountain pine beetles," Mangold said."When forests get to be 80 years old, trees are a little less able to ward off insect attacks. They become weaker, and subject to bark beetles.
"Fire and bark beetles sort of work hand in hand: Bark beetles come into an area, increase the fuel loading with flammable dead trees with needles, then lightning strikes, you get fires, some are suppressed and some aren't. The system regenerates itself for the next forest through this combination of forces," he says.
"Warming temps are probably playing a role, although we’d probably be in this mode with or without warming temps. We do see bark beetles attacking trees other than lodgepole pines higher up the mountainsides, so warming temps are implicated and we see bark beetles completing their life cycles more rapidly in some cases.
"If you get two weeks of minus 30-degree temperatures in winter, that can work to control the beetles, and we haven't had those temperatures recently," Mangold said.
Canadian scientist Carroll told us there has been plenty of evidence showing the size of the outbreak has been exacerbated by human input.
"This comes in several forms: Fire suppression, causing forest to age unnaturally; and at the same time climate change, as warming has increased the area available to pine beetles. The area affected by this outbreak is 10 times bigger than the area impacted previously.
"From an economic standpoint, the mountain pine beetle has created a short-term boom through an effort to extract some value from the dead trees before they rot. Then the slump in the U.S. housing market put the kibosh on all that, so now we have sawmills closing quite regularly, since the market for wood products isn't there," Carroll said.
"There is also an increased risk of catastrophic wild fires; 2003 was quite a bad year for us, but most didn't happen in areas affected by the mountain pine beetle. The longer we go without one of these fires, the lower the potential for one of them becomes, because trees shed needles and fine twigs from the crowns," Carroll said.
"There are other ecological impacts on watersheds without intact forest cover. Alberta is trying to control mountain pine beetles to avoid some of the problems we're having. Alberta, Saskatchewan, and Manitoba all depend on the southern slopes of the Rockies for their water. There's also a hydrology issue around fisheries as well," Carroll said.
What It Means: In the words of scientist Carroll: "It's important to understand the mountain pine beetle kills pine trees, and typically there's quite a viable forest that's left behind. The impact is more economic than ecological in a lot of cases."
« Previous Story |
The Industry Report Home Page
| Next Story » |
Email To A Friend
|
