In January 2024, Marin County approved a plan to remove eucalyptus trees measuring 10 inches in diameter or less across a 150-acre area.
By June, the Monterey County Board of Supervisors approved a $1 million eucalyptus removal program that promised to subsidize half the cost for property owners to remove or trim eucalyptus trees within 100 feet of roads. More than 70 people already requested to apply when it was approved, even though its official launch date had not yet been announced.
In November, registered voters in Oakland’s Wildfire Prevention Zone passed Measure MM, which levies a special tax within Oakland’s Wildfire Prevention Zone to fund the city’s Vegetation Management Plan. The plan includes managing vegetative fuel loads, which includes eucalyptus trees, on city-owned properties and along roadways within areas at the greatest risk of wildfires.
Eucalyptus trees have long been a defining feature of California’s landscape, but in recent years, several communities have been taking action to remove the invasive trees, driven by growing concerns about their oily, highly inflammable nature and potential to fuel wildfires.
When eucalyptus trees were first introduced to the state in the mid-1850s, many Californians welcomed and embraced the fragrant trees, according to the U.S. Department of Agriculture.
Farmers found eucalyptus trees’ rapid growth to be practical. Many claimed eucalyptus had medicinal properties, believing it could cure bronchial and pulmonary problems and “clean the system.” The Central and Southern Pacific Railroads planted the nonnative trees as a sustainable source of timber.
Over time, eucalyptus forests in California became a winter haven for endangered monarch butterflies, providing a place to conserve energy before dispersing in the spring to breed.
“Anti-burning-to-death”
Elizabeth Stage, a board member of the Claremont Canyon Conservancy, said she is not anti-eucalyptus but rather ‘anti-burning-to-death.’
The Claremont Canyon Conservancy is a nonprofit organization based in Berkeley, California that works to restore the canyon’s natural environment and advocate for “comprehensive fire safety strategies.” The organization leads multiple environmental and educational programs, including eucalyptus removal projects.
She, along with the conservancy members, supports Measure MM. “We would be very happy to have all the eucalyptus and other highly flammable species removed,” Stage said.
“Under certain conditions, virtually all trees are flammable” but eucalyptus trees are more likely to contribute high fuel load in case of a fire, Stage said. Constant shedding of bark, oily leaves and long swaying branches make eucalyptus a fire hazard, according to the National Park Service.
The land left barren after the removal of highly flammable vegetation could be vulnerable to erosion and the return of once-removed species. To combat these potential “disasters”, the Claremont Canyon Conservancy and other community groups plant less flammable species to limit the erosion and crowd out fire hazard vegetation, Stage said.
Eucalyptus trees: “beneficial to reducing fire risk”
In the same city of Berkeley, The Hills Conservation Network, another nonprofit organization, works to implement fire mitigation and safety strategies. But this group disagrees eucalyptus removal is an appropriate wildfire mitigation technique.
Dan Grassetti, a board member of the organization, said that eucalyptus trees, along with other tall trees, are “very beneficial to reducing fire risk.”
Tall trees create shade and fog drip, preventing sunlight from reaching the ground and slowing the growth of fire-prone vegetation, he said. “The worst you could do if you wanted to reduce fire risk is to remove the tall tree canopy because it would promote the growth of very, very fire-prone species.”
According to Grassetti, these fire-prone species are short vegetation, such as thistle, hemlock and grasses. Especially in areas adjacent to roadways, maintaining tall tree canopy is the effective practice for mitigating fire risk, he added.
Grassetti and other members of Hills Conservation Network also believe that eucalyptus removal plans often intertwine with agendas for native plant restoration. Eucalyptus trees are considered invasive in California. They grow and spread quickly, outcompeting native plants for water and sunlight, according to the National Park Service.
However, native plant restoration and vegetation management for wildfire prevention should remain separate, Grassetti said. “No matter the species – whether native or not – if they are short, they burn and we have to get rid of them.”
The Hills Conservation Network opposes Measure MM and believes that it was enacted by individuals who want to advance a native plant restoration agenda.
“[Measure MM] is basically being funded by the public under false pretenses,” Grassetti said.
Measure MM and 1991 East Bay Hills Fire
Both organizations – Claremont Canyon Conservancy and Hills Conservation Network – were founded to reflect on lessons learned from the 1991 East Bay Hills Fire.
In October 1991, smoldering embers left from extinguishing a small fire were fanned by strong winds overnight, turning into an inferno. The wildland-urban interface fire destroyed more than 3,000 homes and killed 25 people.
According to a report by the Federal Emergency Management Agency, species not native to the East Bay Hills area, including eucalyptus trees and Monterey pine, dramatically impacted fuel loading. The agency estimated that the heaviest fuel loading occurred in areas where eucalyptus trees had been left untreated, accumulating dead branches and shedding bark.
Measure MM was designed to prevent fires like the 1991 fire from happening again in the Oakland and Berkeley areas, where wildfire risk has been increasing.
More than two-thirds of the registered voters of Oakland’s Wildfire Prevention Zone supported the measure which would generate $2.67 million in the first year. Single-family property owners would be taxed $99 per year, and condo or multifamily-unit owners would be taxed $65 per year.
The measure does not have a detailed year-by-year timeline, Stage said. But, in the second year, the work plan will incorporate lessons learned from the first year. The priorities include vegetation management and monitoring along evacuation routes and parks, she said.
Starting July 1, 2025, Oakland residents in the Wildfire Prevention Zone will begin paying a parcel tax for 20 years to fund wildfire prevention.
