Steamboat Springs The pine beetle epidemic may have peaked in Northwest Colorado in 2008, but some of the long-term impacts are only now starting to surface.
It was known early on that the 4 million acres of lodgepole pine infested by the beetle in Colorado and southern Wyoming would drastically change the landscape. The most obvious danger was the dead trees themselves, that unless removed, presented falling hazards for forest users. There also was significant concern about increased wildfire activity because of the dead timber that surrounds urban areas like Steamboat Springs. Millions of dollars have been spent locally to mitigate the impacts on areas such as Steamboat Ski Area, where logging efforts were under way Wednesday.
Some impacts of the epidemic, however, are harder to control.
“We will be dealing with the impacts of the pine beetle for years to come,” said John Twitchell, district forester for the Colorado State Forest Service.
About 90 percent of the lodgepole pine trees have been killed in the Frasier area, where scientists at the U.S. Forest Service’s 36-square-mile Frasier Experimental Forest have been studying the impacts the epidemic is having on water supplies. It’s important research because 60 percent of Colorado’s water comes from Forest Service lands, said Kelly Elder, a Forest Service hydrologist who has been studying the impacts the dead trees have on water quality and water yield.
“I think we are going to see some increase in the flow,” Elder said.
That still unknown increased water flow comes as communities throughout western Colorado already are preparing for potential flooding resulting from a delayed melt and a record amount of snowfall and water equivalent at upper elevations. The Tower measuring site at 10,500 feet on Buffalo Pass recorded another record Tuesday, with 79.6 inches of water contained in 194 inches of snow.
Before the beetle epidemic, the lodgepole pines extracted water from the ground and kept some snow from ever reaching the ground.
“When you remove in one fell swoop a bunch of those little water pumps, there is going to be more ground water,” Twitchell said.
Elder said a Forest Service report completed in the 1970s showed similar epidemics increased the watershed’s total flow 20 percent about 10 years after the epidemic.
During winter, some snow accumulates on the needles of trees in the forest’s canopy and evaporates before it hits the ground, thereby not contributing to the snowpack. Increases in water flow have been measured with 20 percent of the canopy removed, Elder said.
Trees also affect water flow when they die and stop sucking up water through their roots.
By the end of summer, trees attacked by beetles are taking in as much as 50 percent less water, said Robert Hubbard, a Forest Service ecologist.
It’s still too early to tell exactly what the impact will be from the latest epidemic, Elder said.
Routt National Forest hydrologist Jamie Krezelok said they are monitoring whether the epidemic’s impacts could overwhelm culverts, riverbanks, cause landslides and damage roads.
“It’s easy to see how there would be a measurable impact,” Twitchell said.
Until those impacts are quantified, however, the evidence might be more anecdotal.
“From my personal experience, it does seem that some areas (in the forest) I would expect to dry out have stayed wet,” Twitchell said. “I’ve heard other people say that.”
To reach Matt Stensland, call 970-871-4247 or email mstensland@SteamboatToday.com