In just 10 years, fires, drought, and insect infestations have devastated close to a third of forests in the southern Sierra Nevada mountains, a new study finds.
The region, which extends from Lake Tahoe in the north to the Sequoia National Forest in the south, has been hit by persistent drought, made more severe by climate change, which has left pines more vulnerable to wildfires and bark beetle infestations. From 2011 to 2020, 30 percent of conifer forests in the southern Sierra Nevada succumbed to these threats, according to an analysis of U.S. Forest Service data on tree cover, tree height, and the extent of recent wildfires.
Over the same period, 85 percent of the region’s dense mature forests either died or were substantially thinned. The findings were published in the journal Ecological Applications.
“It’s kind of a wake up call, even to those of us that are kind of steeped in this field,” Zackary Steel, a postdoctoral researcher at the University of California, Berkeley and lead author of the study, told the Sacramento Bee. “We’re moving from knowing this is a problem to quantifying the problem.”
The paper calls for more prescribed burning in California forests, many of which have become overgrown as a result of decades of fire suppression. Small, controlled burns can make forests more resilient to drought and wildfire.