The effects of drought, heat, wildfires and insect infestations, if unchecked, could leave forests throughout the Rocky Mountains unrecognizable within decades, a report released Wednesday says.
The report, based on U.S. Forest Service quantified projections, was prepared by the Rocky Mountain Climate Organization and the Union of Concerned Scientists.
A panel of speakers held a telephone conference Wednesday with media outlets to discuss the data.
Panel members were report co-authors Jason Funk, a climatologist at the Union of Concerned Scientists, and Stephen Saunders, president of the Rocky Mountain Climate Organization; Diana Six, professor of forest entomology/pathology at the University of Montana; Park Williams, a professor at Columbia University’s Lamont Doherty Earth Observatory; and William Anderegg, a National Oceanic and Atmospheric Administration post-doctoral fellow at Princeton University.
Among the most salient points in the report:
Bark beetles are killing trees on a larger scale than ever seen before. In the last 15 years, beetle-killed trees cover an area nearly the size of Colorado.
From 1984 to 2011, there has been a 73 percent increase in the average annual frequency of wildfires of 1,000 acres or greater.
In the West, temperatures have risen on average about 2 degrees Fahrenheit since 1895 and drought has become more widespread.
Forest Service projections find that if heat-trapping gases continue to increase at the recent rate, by 2060, the area climatically suited for lodgepole pine could decline by 90 percent; for ponderosa pine, 80 percent; for Engelmann spruce, by 66 percent; for aspen, 61 percent; and for Douglas fir, by 58 percent.
Driving the scourges is climate change, aided and abetted by diseases, development by humans and forest management, the report says.
Six said lack of precipitation and increasing temperature are responsible for beetle infestations,
“Hot and dry is the trigger for beetles,” Six said. “Pine beetles are expanding all the way to the Yukon. This screams that something is wrong.”
Spruce beetles, ips beetles and fir beetles show the same trend, Six said.
As temperatures in the West increase, conifers will move higher and be replaced by drought-tolerant species or, in their absence, shrubs and grasses, Williams said.
Anderegg said aspen have little margin for error. Aspen already are a high-elevation species and they don’t propagate through seed like conifers, he said.
The iconic aspen, known for its wildlife habitat and fall colors, was severely affected by the drought of the early 2000 decade, Anderegg said. In Colorado, 500,000 acres, one-fifth of the state’s aspen stands, were affected by the drought.
Funk said that even with modest rises in temperature, it will take aggressive action to hold the line. Otherwise, he said, temperatures could rise 6 percent by mid-century and 10 percent by the year 2100.
Panelists said the numbers they were tossing out are projections, not predictions.