The deadly fires that destroyed homes in Pacific Palisades and Altadena also destroyed the lush canopy of leaves and pine needles that had kept residents cool and shady for generations.
Now, more than a year later, the trees that escaped the flames are disappearing at a disturbing rate.
According to preliminary results from the University of California research team, about 20% of the trees remaining on the road have disappeared since the January 2025 fire siege.
Experts say many of the hundreds of missing trees may have recovered from fire damage.
Edith de Guzman cuts the cambium layer of carrot wood near Aiglon Plaza in Pacific Palisades to see if it is green and healthy.
The results of the survey of about 500 trees in the Palisades and 1,500 trees in Altadena – including conifers, palms, Chinese elms and carrot trees – appear to confirm worrying patterns in the burn scars observed by arborists and local volunteers, who said the damage will likely continue for years to come.
It appears that several factors are at play.
Even during the reconstruction of Palisades and Altadena, local governments made only limited efforts to water the trees. Also, construction contractors have been quick to remove trees in the path of construction, while debris removal crews have cut down live trees that they mistakenly believed to be dead.
In response to the ongoing loss of trees, a group of arborists and volunteers are working to keep the recovering trees alive – and hope to someday begin planting the next generation of burn-scarred urban forests.
While many homeowners view trees through the prism of maintenance costs — routine pruning can be expensive, and tree roots can wreak havoc on sidewalks and underground pipes — experts say the benefits of trees are numerous and well-documented.
The shade they provide and the process of evapotranspiration – where water on the surface of leaves evaporates and carries away heat just like human sweat – can cool a neighborhood by more than 10 degrees. This cooling reduces the risk of heat-related illnesses and can reduce a homeowner’s energy costs.
Trees also improve air quality, improve the mental health of residents and reduce the risks of floods and landslides. Meanwhile, fire experts say properly spaced and well-maintained trees do not pose a significant fire risk.
Edith de Guzman, a climate change, water and urban forestry researcher at UCLA, is studying trees in the burned area with her team. Researchers conducted their first assessment in the months after the fire, and donned orange vests to do it again last month.
Edith de Guzman uses a hypsometer to calculate the height of a tree in Pacific Palisades.
Particularly worrisome to De Guzman was the discovery that nearly 2 out of every 10 trees the team went back to check were missing because his team was only looking at public street trees – which the city and county have authority over and work to protect – as opposed to trees on private property, whose maintenance or felling is largely at the discretion of property owners.
“It’s a different story on private property – except for protected species,” he said. However, Public Trees, “we are still seeing removals that are unnecessary, and the city is not sure who is responsible.”
The LA City Bureau of Street Services did not respond to a request for comment.
The fire killed and damaged a significant portion of the area’s urban tree cover – both private and public – although precise estimates are difficult.
Almost immediately, the remaining trees faced trouble.
David Card, Board Chairman Palisades Forestry Committee, Told that trees started falling shortly after the fire. In the chaotic situation, it was unclear which organizations or agencies were responsible.
Rebecca Latta, Co-Founder Altadena Green, Said that when the U.S. Army Corps of Engineers began debris removal efforts, leadership worked with them to save the trees, but Army Corps contractors often pressured homeowners to approve tree removal and incorrectly identified native oak trees – which had no leaves at the time – as dead.
Chinese elm trees grow atop the Pacific Palisades.
Once private contractors arrived to begin reconstruction, they often removed trees on private properties that they determined were in the way — and sometimes also removed public street trees that they did not have rights of way, advocates said.
Also, neither the city of Los Angeles nor the county routinely waters living public trees—which arborists say is necessary to help damaged trees recover. The county did a round of watering in Altadena, Latta said, but found it too expensive. According to Card, the city did not provide water to the Palisades due to a lack of resources.
LA County Public Works said it is “committed to preserving the community’s public trees.” The department said it regularly waters newly planted trees and will continue to assess the needs of mature street trees.
Therefore, local groups are coming forward to save the trees.
The Forestry Committee began sending two watering trucks around the Palisades: a 2,000-gallon tanker from a landscaping company and a 500-gallon tank in the back of a trailer. Altadena Green began conducting property tree surveys to help residents understand which damaged trees would likely survive and how to care for them.
The Forestry Committee is also working on a long-term tree-planting program for the Palisades that will use fire-resistant tree species, Card said — although the Los Angeles Department of Water and Power has asked the Forestry Committee to wait for a year as it begins work on burying power lines underground. Excavation will likely take place on plots that typically have street trees.
Researchers Oliver Khachikian, Matthew Murphy, Mariana Vargas and Sophia Reimer prepare to survey trees near Eglon Plaza in Pacific Palisades.
In the meantime, saving existing trees remains a priority for tree doctors.
Laura Travnitz, an Altadena resident who lost her home in the fire, recalled that an Army Corps contractor pressured her to remove more than a dozen fire-stricken trees on her land. Now, they’re just stumps. Some already have tiny green shoots reaching toward the sky.
“I am 65 years old,” she said. “I’m not going to be around for them to grow again.”
