Los Angeles tree advocates hope their vital work recovers from devastating fires

LOS ANGELES — Some people across Los Angeles have worked for years to increase the number of trees that give respite from heat and air pollution.

The tree advocates have confronted increasing drought, bad trimming and objections from neighbors who resent leaves and sap. Now they wonder what this month's devastating fires have done to their efforts.

City arborists have ''sobering'' photographs of large trees knocked onto homes and parkways from the same powerful winds that sent fires out of control, said Bryan Vejar, associate director of community forestry for TreePeople, an environmental nonprofit that works to plant and care for trees across Los Angeles. Other images show scorched canopies, he said.

The powerful Santa Ana winds damaged trees in South Los Angeles, Watts and Inglewood, historically underserved neighborhoods with less shade and TreePeople's primary focus areas.

The air is still so bad that field crews cannot yet work safely. When they go out, he said, they expect to to find snapped, broken or dried out young trees.

New trees are vulnerable, and volunteers often have to go out and water them for the first few years.

''Events like this can greatly increase our mortality rates,'' Vejar said.

When it's safe, urban tree experts will go out to inspect, re-stake and retie trees toppled by winds, and remove and replace those that were lost.

Replanting trees in burned neighborhoods is harder because of climate change, said Will Berleson, a professor at USC's Department of Earth Sciences and researcher with the university's Urban Trees Initiative. Even though many of the city's mature trees might be 30 or 40 years old, they ''started growing at times when it was not as hot and didn't have these kinds of wet and dry fluctuations that we seem to be seeing now,'' he said.

Some experts see tree loss as an opportunity to teach Los Angeles residents about where they live and which plants are the best fit and that's not necessarily the iconic ones from Hollywood movies. They would like to replace non-native species like palms — which are more closely related to grasses — with trees that provide shade and can withstand extreme heat and drought.

Trees such as the coast live oak are a good option, said Aaron Thomas, director of urban forestry at the environmental nonprofit North East Trees. They are native to the region and are fire resilient — in fact, they need to burn to reproduce, he said.

Thomas, who grew up in Altadena, has family members who lost homes to the Eaton Fire north of Pasadena, which has burned more than 7,000 structures. His brother's home burned, but the five coast live oaks in his backyard survived.

But planting trees with climate-resilient features such as large canopies isn't always easy, and cities must consider community input when deciding what to plant. Trees that provide a lot of shade can make it difficult for drivers to see around corners and where space is at a premium, sometimes there's just not enough room above or below ground to plant them.

Berleson added that it will take a long time for neighborhoods to look like they did before the fires.

Vejar said his group knows there will be setbacks, but that is reality.

''It's climate change. It's water restrictions. It's extreme weather events,'' he said. ''And so in the face of this, all we can do is continue to build and rebuild and steward our urban forests in such a way that makes it more resilient in the face of these extreme weather events.''

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