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”→
Feds spend more than $2.6 billion on fire suppression
By Bob Berwyn
For the first time in the era of modern record-keeping, wildfires burned across more than 10 million acres in 2015, mainly due to a series of large fires in Alaska.
According to the U.S. Forest Service, there were more than 50 fires that exceeded 50,000 acres, and 20 fires exceeded more than 100,000 acres. The fires destroyed more than 4,500 homes and other structures and killed 13 wildland firefighters.
The big wildfire season came after two-year lull, when the total wildfire footprint stayed below 5 million acres. For the last years, the average now stands at about 6.6 million acres.
The uptick in fires is no surprise to experts, who have been warning that global warming will result in bigger burns. Alaska, for example, reported its second-warmest year on record in 2015. Since 2000, fire seasons have grown longer, and the frequency, size and severity of wildland fires has increased.
After combining data from field observations with climate model projections, the research team concluded that 72 percent of the region’s needleleaf evergreen forests will die by 2050, with nearly 100 percent mortality by 2100.
It’s pretty clear that the die-off is already under way. Even drought-resistant species like piñon pines were hit hard by a drought in the early 2000s. A massive bark beetle infestation wiped out millions of acres of lodgepole pines in the southern Rockies, and spruce beetles have taken a big toll on once-lush spruce forests in southern Colorado. Continue reading “Can the Southwest’s forests survive global warming?”→
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.
An extensive tree-ring study in the Northeast suggests a widespread and steady decline in the health of sugar maples, one of most economically and ecologically important trees in the eastern United States and Canada.
The decline started showing up in the 1970s a decline in the growth rate of of sugar maple trees, but the reasons are still unclear, according to the State University of New York researchers who recently published their findings in the open-access journal “Ecosphere.” Continue reading “Environment: More maple tree woes”→
Forests may grow faster as atmospheric CO2 increases, but that doesn’t mean they’ll absorb more of the heat-trapping gas. Instead, a shortage of nitrogen means plants won’t be able to fix as much carbon as projected by some climate models.
“Forests take up carbon from the atmosphere, but in order for the plants to fix the carbon, it requires a certain amount of nitrogen,” said researchers Prasanth who took a close look at the chemistry of secondary forests that are regrowing after deforestation, wood harvest and fires.