Los Angeles County has a robust urban forest, but the region’s trees are not evenly distributed among communities, creating great variations in social, environmental and health benefits to residents, according to a new analysis led by Loyola Marymount University and the nonprofit organization TreePeople.
LMU’s Center for Urban Resilience partnered with TreePeople, the consulting group SavATree and the University of Vermont Spatial Analysis Lab to study the distribution of trees across the county. The analysis was completed using imagery and LiDAR – technology used by law enforcement for police radar – acquired in 2016 through a county consortium.
“If you look at data across the county, L.A. is so varied in terms of tree coverage,” said CURes Managing Director Michele Romolini. “What we want to do is to dig in and help at the local community level to grow forests in those places that really need them.”
Trees can provide communities with such benefits as improved water quality, reduced stormwater runoff, cleaner air, lower temperatures and enhanced property values.
Using U.S. Census block groups as the unit of analysis, the team found that in the city of Los Angeles, about one-fifth (18 percent) of the tree canopy grows where only one percent of the city’s population lives. Areas where trees are plentiful include Pacific Palisades, Los Feliz, Brentwood and Shadow Hills.
Meanwhile, areas with the highest need of a protective tree canopy are in the northern and southeast parts of the county — especially along the 110 Freeway corridor — and in the northeast San Fernando Valley. The team made these determinations using “lenses” that factored in socioeconomic data in the hottest areas, and where chronic health conditions were most prevalent.
“This important study highlights how TreePeople’s Calles Verdes (Green Streets) program in the San Fernando Valley and in South L.A. will increase the urban tree canopy in low-income neighborhoods, which are the most vulnerable to extreme heat and have the highest rates of public health issues,” said TreePeople CEO Cindy Montañez.
Romolini said her hope is that by focusing on these vulnerable areas, researchers will be able to guide decisions on how to both expand and preserve the tree canopy.
Among the other findings:
- Recreational and residential properties, along with public rights-of-way, have the largest amounts of tree canopy.
- The biggest opportunity for more tree coverage is on residential sites.
- Home value is positively correlated with tree canopy; the higher the home value, the greater the tree cover.
To see the full presentation, visit TreePeople.org/LAtreecanopydata.
