From the same article.
Easier Said Than Done
U.S. Forest Service wildland firefighters hacked a line into the earth, around a patch of land on the Yuba River District near Pendola, overlooking Bullard’s Bar for one day of work. A “hot shot” crew and crew members from two engine companies gathered for the day’s work.
“This day started a few years back,” Jennifer Hinckley laughs dryly. Hinckley is a fire and fuels specialist for the Tahoe National Forest. And she does a lot of paperwork: before the first torch even can drip fire on the ground, federal law requires extensive environmental review.
Even with approval, federal wildland managers waited months for the right weather and environmental conditions here. Hinckley says those criteria range from wind speed and temperature, to how much water is in the soil. It was a very wet spring; on-and-off rains created several months of delay here.
Thick vegetation in the understory is a limiting factor, too. Hinckley says her crews often need to chop and flatten vegetation to make safe conditions for burning.
Even when all of the stars align, Hinckley says she might not have warm bodies for the job. That happened last fall, when fires up and down the state kept fire crews hamstrung.
“I didn't have crews to perform prescribed burns," she says, "because the wildfires take priority.”
Even when the permit is done and the weather is right and crews are available, the air might already be too polluted to add more smoke to the mix. Air regulators grant permission for burn days, and it’s hard to get: regional atmospheric conditions mean that smoke from Sierra Nevada forests funnels toward the central valley, where air pollution is consistently bad.