Spruce beetle infestation on the San Juan National Forest grew to more than 120,000 acres in 2015, according to an annual aerial survey of Colorado’s trees.
To address this and other forest-health issues, the Forest Service is planning salvage sales of dead spruce at different locations. The public may have an opportunity to comment on larger, more complex timber proposals later this year.
In the Pagosa Ranger District near Wolf Creek Pass, a small salvage sale is being prepared for about 100 acres of dead spruce in 2016. A nearby planning effort is investigating the future salvage of additional dead spruce that can be accessed from the Wolf Creek and Falls Creek roads.
Both proposals focus on the harvest of dead trees to be sold, retention of live green trees and use of revenue from timber sales to promote reforestation in areas of heavy mortality.
Spruce beetles primarily target Engelmann spruce, which grow in high-elevation forests. Dead spruce trees can remain standing for several decades and retain value as commercial timber for up to a decade or more.
In the Dolores Ranger District, a timber sale is being considered for about 900 acres of mixed spruce and aspen in the Taylor and Stoner mesas area to improve resilience of spruce forests not yet affected by the beetle outbreak but already experiencing spruce budworm activity.
Thinning green stands can improve forest health by adding diversity of size and age class and encouraging natural regeneration, but thinning cannot stop the spread of insects.
In the Columbine Ranger District, an integrated forest-health project across several thousand acres north of U.S. Highway 160 between the Piedra River and the Vallecito area is investigating the potential for salvage sales in dead forests, resilience treatments in live spruce and aspen forests, as well as fuels reduction and prescribed burning.
The mountain pine beetle is not a problem in the San Juan National Forest. This outbreak was most visible along the Interstate 70 corridor and in forests along the Front Range.