Bark beetle outbreaks and wildfire alone are not a death sentence for Colorado’s beloved forests—but when combined, their toll may become more permanent, new CU Boulder research shows.
It finds that when wildfire follows a severe spruce beetle outbreak in the Rocky Mountains, Engelmann spruce trees are unable to recover and grow back, while aspen tree roots survive underground. The study, published last month in Ecosphere, is one of the first to document the effects of bark beetle kill on high elevation forests’ recovery from wildfire.
“The fact that Aspen is regenerating prolifically after wildfire is not a surprise,” said Robert Andrus, who conducted this research while working on his PhD in physical geography at CU Boulder. “The surprising piece here is that after beetle kill and then wildfire, there aren't really any spruce regenerating.”
Andrus’ previous research found that bark beetle outbreaks are not a death sentence to Colorado forests—even after overlapping outbreaks with different kinds of beetles—and that spruce bark beetle infestations do not affect fire severity.
Read more at: University of Colorado at Boulder
A forest in the San Juan range of the Rocky Mountains, with dead Engelmann spruce trees alongside live aspen trees. (Photo Credit: Robert Andrus)