Twice burned, Sonoma County’s Pepperwood Preserve has long-term stake in wildfire science and recovery
Brittle, blackened leaves on a small bay laurel tree remain frozen just as they were ruffled by the hot north wind of the Kincade fire that stormed Pepperwood Preserve three weeks ago, scorching the 3,200-acre property in the Mayacamas Mountains for the second time in three years.
Nearby, in Hendley Flat at the north end of the sprawling preserve, the shattered 20-foot stump of a venerable “grandmother” valley oak tree stands among downed limbs, another remnant of the massive blaze that scorched 60% of the property dedicated to conservation and education.
“I actually cried over this tree,” said Michelle Halbur, the preserve ecologist, noting that coyote pups had been spotted within the tree’s base, hollowed out by an earlier fire.
Nearly half of Pepperwood, some 1,658 acres, was scarred by both the Tubbs fire in 2017 and Kincade blaze, snuffed out last week after burning for 13 days, destroying 174 homes and covering 120 square miles, becoming the largest fire in Sonoma County history.
The fires’ one-two punch have cost Pepperwood more than $5 ?million in rebuilding and restoration work. But they also have further positioned the preserve as a leader in the science of wildfire recovery, with the unique opportunity to document the consequences of repetitive fires and climate change on California’s wildlands.
Already, a Sonoma State University team is at work using lidar, a laser-based measurement system, to determine how much fire fuel remains at Pepperwood, and researchers have identified more than 6,000 trees for long-term study of how the woodlands evolve over time.
A deployment of Cal Fire dozers stopped the Kincade fire on a Pepperwood ridge, and preserve staffers are now racing to repair 15 miles of tracks scraped bare by the 45,000-pound machines before the winter rains arrive.
With hand tools and a tractor, workers led by preserve manager Michael Gillogly are smoothing over the tracks that cover about 22 acres, as wide as a two-lane road in some places. About a mile had been restored Friday, he said, with volunteers and a contract crew soon to join the effort.
A few sprinkles of rain now would be a boon, triggering regrowth of grasses on bare dirt, but substantial rain would create gullies in the dozer lines, carrying sediment into creeks that feed the Russian River and support imperiled salmon and steelhead runs.
“Dozer tracks are more devastating ecologically than the fire,” Halbur said.
Rain will eventually restore the preserve’s 900 acres of grasslands, she said, and most trees - even those burned twice since 2017 - will survive in a landscape that evolved with wildfire.
“A lot of native plants do just fine with fire,” Gillogly said. “When we get rain they will spring right back.” Even trees that die serve a purpose, opening up the forest canopy to let more sunlight reach the ground, he said.
Lisa Micheli, president of the nonprofit foundation that operates Pepperwood, said the firebreaks cut by Cal Fire dozers were critical to containing the Kincade. On the pivotal night of the firefight, Oct. 27, winds at Pepperwood were recorded at up to 60 mph.
The preserve’s open space served as a battleground for stopping the blaze that roared in at night, when no Cal Fire aircraft could operate, she said, calling the scenic lands devoted to science a “tactical location” for firefighters.
Ben Nicholls, division chief ?of Cal Fire’s Sonoma-Lake-?Napa Unit, said dozer lines cut in Pepperwood stopped the fire on the preserve, keeping it out of the Mark West drainage.
“It was a huge win that we were able to hold it there,” he said, preventing a repeat of the Tubbs fire’s rampage down the drainage into Larkfield and northeast Santa Rosa.
Ten additional fire engines also were dispatched to the Pepperwood area to keep the fire from coming over a strategic ridge, he said.
Chad Costa, a Petaluma Fire battalion chief who managed the area from Calistoga to Larkfield, said the roads and grazed land in the preserve allowed dozers and engine crews to halt the fire’s southern front.
Kim Sone, a Cal Fire division chief and a forester, said the agency’s erosion control work started at Pepperwood as soon as the fire was contained Nov. 6, using some of the same dozers that forged firebreaks. Cal Fire reports said up to 67 dozers were committed to the Kincade fire, which began Oct. 23 near a malfunctioning PG&E transmission tower close to The Geysers geothermal field in northern Sonoma County.
Dozers built berms to divert water off the bare tracks and pushed dirt out of streambeds, while brush, gravel and straw wattles were also applied to curb erosion, Sone said.