The latest results from aerial surveys of Colorado forests shows that spruce beetles are doing the most damage, with infestations detected on 409,000 acres across the state, expanding onto 182,000 acres of previously unaffected forests. Since 1996, spruce beetle outbreaks have caused varying degrees of tree mortality on more than 1.5 million acres in Colorado.
The mapping shows spruce beetles spreading outward from the San Juans to the West Elk Mountains, the Sangre de Cristo Mountains and into the northern part of the state around Rocky Mountain National Park. See the full report here: http://www.fs.usda.gov/goto/USFSR2ForestHealth.
State forest experts said it was the fourth year in a row that spruce beetle outbreaks caused widespread tree mortality. As populations of spruce beetles expand, they are starting to affect higher-elevation stands of Engelmann spruce. The report says blowdown events, combined with long-term drought stress, warmer temperatures and extensive amounts of older, dense spruce, have all contributed to the ongoing spruce beetle outbreak. Continue reading “Aerial forest surveys track continued spread of spruce beetles across Colorado forests”→
Climate, topography likely more significant, researchers say
Colorado researchers have added another chapter to the long-running debate over beetle-kill and wildfires, finding that spruce beetle infestations haven’t increased the severity of wildfires in southwestern Colorado.
Aerial surveys help track forest changes over time
By Bob Berwyn
FRISCO — There’s good news and bad news from Colorado’s forests. Mountain pine beetle activity has faded to the lowest level since 1996, but spruce beetles continue to spread in the San Juans and in northwestern Colorado.
Pine beetle infestation slows, but spruce beetles continue to spread
By Summit Voice
FRISCO — There’s good news and bad news for Colorado forests, according to state and federal officials, who said last week that the mountain pine beetle epidemic slowed dramatically in 2013, while spruce beetles continued to spread.
Statewide, mountain pine beetles were active on 97,000 acres in 2013, the lowest acreage of active infestation in 15 years. Since 1996, mountain pine beetles have killed trees across 3.4 million acres.
And the trigger of for the spruce beetles is drought that’s linked with long-term changes in sea-surface temperatures in the Northern Atlantic Ocean, a trend that is expected to continue for decades, according to a new study by scientists with the University of Colorado, Boulder.