A research study has found that increasing house sizes in the Los Angeles area have drastically reduced the number of trees shading the region's landscapes—regardless of geographic location of socioeconomic status.
Researchers with the USC Spatial Sciences Institute, led by Su Jin Lee, Professor Travis Longcore, Catherin Rich, and John P. Wilson have published a study finding that green cover for single-family home lots declined anywhere from 14 to 55 percent the Los Angeles area, with almost no single area spared from decline.
The study was published in the journal Urban Forestry & Urban Greening and announced in a press release on EurekaAlert.
As noted in the study, much of the "de-greening" of Los Angeles occurred as the city implemented a "Million Trees" campaign. The researchers began by taking an inventory of single-family parcels in the largest 20 largest cities in the Los Angeles basin, starting with the parcels that had added square footage to the home since 2007.
Baldwin Park led all areas in reduction, seeing a 55 percent loss of green cover on single-family residential lots in the mere span of nine years.
Other areas in the study that had at least 20 percent loss in cover included Pomona, Downey, Sylmar, Compton, and San Pedro/Port of Los Angeles.
The study noted one prominent exception: Pasadena, which maintained its verdant condition.
"[Study author] Longcore believes changing social views on the preferred size of single-family homes is the largest driver of tree cover loss, along with the increase in paved surfaces like walkways, driveways and swimming pools that come with home expansion," according to the press release.
FULL STORY: When single-family homes killed L.A.'s urban forest
Preserving Altadena’s Trees: A Community Effort to Save a Fire-Damaged Landscape
In the wake of the Eaton Fire, Altadena Green is working to preserve fire-damaged but recoverable trees, advocating for better assessment processes, educating homeowners, and protecting the community’s urban canopy from unnecessary removal.
LA’s Trees Absorb More Carbon Than Expected, But Can’t Do It Alone
A USC study finds that Los Angeles’ urban trees absorb more carbon than expected, but while they provide crucial environmental benefits, they cannot replace the urgent need for systemic emissions reductions.
Mapping a Greener Future: Cal Poly Tackles Urban Canopy Challenges
Cal Poly, in partnership with Cal Fire, is leading the development of California’s new Strategic Plan for Urban Forestry, combining advanced data tools and interdisciplinary collaboration to expand tree canopy cover.
What ‘The Brutalist’ Teaches Us About Modern Cities
How architecture and urban landscapes reflect the trauma and dysfunction of the post-war experience.
San Diego to Rescind Multi-Unit ADU Rule
The city wants to close a loophole that allowed developers to build apartment buildings on single-family lots as ADUs.
The VW Bus is Back — Now as an Electric Minivan
Volkswagen’s ID. Buzz reimagines its iconic Bus as a fully electric minivan, blending retro design with modern technology, a 231-mile range, and practical versatility to offer a stylish yet functional EV for the future.
Study: Walkability Can Help Reduce Dementia Risk
Walkable neighborhoods offer natural opportunities to stay active and engaged with friends and neighbors, increasing residents’ chances of remaining mentally and physically healthy longer.
Empower LA: The LA2050 Grants Challenge
The 2025 LA2050 Grants Challenge invites organizations to become outreach partners and help mobilize Angelenos to vote on how $1 million in grants will be allocated to address key local issues like homelessness, income inequality, and park access.
Take a Walk: Why Step Count Is the Most Valuable Fitness Metric
Step count remains the most valuable fitness metric for longevity and well-being, offering a simple yet powerful way to track daily movement, reduce health risks, and promote active lifestyles without reliance on complex data or technology.
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.
City of Edmonds
City of Albany
Harvard GSD Executive Education
UCLA Lewis Center for Regional Policy Studies
Mpact (formerly Rail~Volution)
City of Piedmont, CA
Great Falls Development Authority, Inc.
HUDs Office of Policy Development and Research