Diverse tree species help
By Cayla Vidmar
If you’ve looked at the trees on the hillsides around Crested Butte, you may have noticed a reddish tinge to the needles. Because of the die-off caused by bark beetles around the state, and particularly over Monarch Pass, this discoloration raises some concerns about the bark beetle in Crested Butte. Sam Pankratz, assistant district forester for the state Forest Service, explained that the discoloration is normal, and our diversity of tree species in Crested Butte helps keep bark beetles at a normal level.
“I’ve dealt with this question a couple times in Crested Butte around this time of year. If people are noticing a red tinge to the trees, it’s very likely they’re noticing the pollen cones this time of year,” said Pankratz. “The trees also respond to drought conditions, which could also be causing the red tinge.”
The Gunnison Valley is home to multiple species of trees, including Engelmann spruce, lodgepole pine, and Douglas fir. According to Pankratz, bark beetles that infest a specific tree species will take out only pockets of trees when there is a diversity of species in the forest. “We do have a variety of different bark beetles that are endemic [or native] to our forests around Crested Butte,” says Pankratz.
Pankratz explains that the main areas where the Forest Service sees beetle impact are Taylor Canyon, Taylor Park, and “a few bugs are working their way up Cement Creek on lower elevation Douglas fir.” However, Pankratz wants to make it clear that what he’s seeing is normal. “What I want folks to understand is that the beetles are native, and they’ve coexisted with these trees longer than we have.”
Pankratz explains that the bulk of the beetles in Colorado are moving along the Continental Divide, “mainly because of the predominant wind direction pushing them along the divide.” He says, “I don’t want to sugar-coat this; we could see some more mortality due to these things, but fortunately at the north end of the valley we have a larger diversity of trees, which helps.”
The drought conditions we’ve seen this spring, along with climate change, influence beetle activity, according to Pankratz. “There are certainly indications that climate has influenced how these bark beetles have acted in our forests,” he says.
Another influence on bark beetle is the age of the trees; a forest with less diversity in the age of trees is more susceptible to widespread beetle damage.
“We have a mature stand of trees in the north end of the valley,” says Pankratz. “We’ve taken out one of those natural regimens by taking out fire, so we’ve taken out one tool that nature uses to create diversity in our forests in age, species, etc.,” he says.
Pankratz explains that the responsibility of land managers is to mimic the natural regimens in forests, which helps diversify the trees and helps keep the forest healthy.
“One of the attitudes we’re trying to shift in land management is the negative attitude people have when they see us cutting down trees. We’re trying to mimic those natural disturbances on the landscape when we cut down trees—it’s nothing like the widespread logging people associate with,” he says, referring to general land management to mimic natural forest disturbances, not necessarily associated with bark beetle management.
While bark beetles are present in the area, Pankratz says it’s not at epidemic levels like we’re seeing over Monarch, “where it comes in and kills everything within two years.”
To find out more about land management projects or bark beetles, Pankratz invites you to visit their project sites. Get more information by calling (970) 641-6852 or email CSFS_Gunnison@mail.colostate.edu.