By Adam Kaye, San Dieguito River Valley Conservancy
RANCHO SANTA FE — What does conservation look like for Jonathan Appelbaum?
With a glance, the resource ecologist takes in conservation at the Arroyo Preserve in Rancho Santa Fe, where crews are removing invasive trees as part of a 12.5-acre restoration project.
While looking to his right, Appelbaum identifies a restored stretch of the San Dieguito River, where sycamores and cottonwoods stand tall and the shimmering, yellow leaves of willows signal fall in San Diego County. As the river wanders through this tableau of native, riparian trees, an endangered bird – as if on cue – lets out its mewling call.
“That’s a California gnatcatcher,” Appelbaum said.
Looking left, the picture darkens. A dense grove of red gum eucalyptus has crowded out the natives. So have unwelcome fan palms, tamarisk trees, reeds and pampas grass. There isn’t any birdsong, but from this particular eucalyptus forest, on this day, a chorus of chainsaws emits its cacophony.
“That’s the sound of hard work,” Appelbaum said.
As a consultant for the San Dieguito River Valley Conservancy, Appelbaum manages the $1.5 million restoration of riparian habitat funded by the state’s Wildlife Conservation Board. In February, the board announced its approval of the conservancy’s application for funding.
Months later, on a December morning, crews from the California Conservation Corps and San Diego Canyonlands cleared undergrowth and deadfall to prepare for the felling of large eucalyptuses and palms. Crews from West Coast Arborists brought down the largest trees, which a helicopter will remove from the fragile waterway.
Before long, the work window will close. Tree cutting will be off-limits from Jan. 15 through Sept. 15, the nesting season for raptors.
The removal of smaller vegetation, including thickets of acacia and salt cedar, can continue until March 15. After that, state and federal permits require silence from power equipment to avoid bothering nesting birds.
Beyond their importance for birds and other wildlife, thriving riparian corridors are critical for climate change resiliency and the safety of property and people.
A healthy riparian community populated with fire-resistant native trees and plants serves as a natural fire break. Invasive species, by contrast, provide abundant fuel for wildfires.
From their ground-level deadfall to the tips of their canopies, eucalyptus trees and the volatile oils they contain burn furiously in a wildfire and can send embers flying into the wind for up to a mile. In the words of the fire service, invasive palms become “Roman candles.”
Wildfire safety has been a driving force behind habitat restoration and its funding in the Santa Fe Valley.
“In 2007, the Witch Creek Fire burned through the valley – homes lost,” Appelbaum said. “In 2014, the Bernardo Fire burned through [nearby] Lusardi Creek – homes lost.”
The work at the bustling restoration site will also reduce flood risks and improve streamflow. Appelbaum expects surface and groundwater levels to rise after the water-sucking eucalyptus forest is gone. That could encourage the return of southern steelhead trout, an endangered fish that once spawned in the San Dieguito River.
At Arroyo Preserve, the three-year project is scheduled to continue through the summer of 2027. The state grant covers monitoring the restoration area after the project is finished.
As designed, the project will provide important habitat for the endangered least Bell’s vireo and light-footed Ridgway’s rail and connections to other conserved lands for mammals such as mountain lion, coyote, bobcat, mule deer and gray fox.
Plans for revegetation include seed, live cuttings and purchased plants at 125 plants per acre for a total of more than 1,500 plants.
The project is part of a larger, 181-acre restoration program in Santa Fe Valley, which began in 2015. Through the years, grants and gifts have funded the treatment of more than two-thirds of that area.
Collaborators include the Rancho Santa Fe Association, which owns the property, Rancho Santa Fe Fire Protection District, San Dieguito River Park JPA, Fairbanks Ranch Association, U.S. Fish and Wildlife Service, California Native Plant Society, California Conservation Corps, San Diego Canyonlands, Resource Conservation District of Greater San Diego County and many others.
