Study: House Sizes Increase at the Expense of Tree Canopies

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.

2 minute read

May 3, 2017, 12:00 PM PDT

By James Brasuell @CasualBrasuell


Hollywood Blvd

Andrey Bayda / Shutterstock

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.

Monday, May 1, 2017 in EurekAlert

"Planetizen federal action tracker" logo superimposed over black and white image of US Capitol dome.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

October 28, 2026 - Zachary Whalen

A car drives through a puddle, making a large splash. Rain pours down.

California plans to bury El Niño’s downpour

If the state plays its cards right, it may be able to store a billion acre-feet of El Niño’s water in aquifers.

October 28, 2026 - Grist

Lake Powell with much of the water evaporated.

Desperate measures: Advocates weigh draining Lake Powell to fill Colorado River

Draining the reservoir could reduce evaporation losses by a couple hundred thousand acre-feet.

October 30, 2026 - Yale Environment 360

Nithya Ramen talks to an older man. She is smiling and wearing a yellow dress. They are both outside.

Los Angeles just elected an urban planner as its mayor

Transportation analysts are optimistic that Raman will be more aggressive in addressing transit issues than Bass.

November 7 - Los Angeles Times

Mamdani behind a microphone, in front of a snowbank

Mamdani’s pied-à-terre tax survives legal challenge

A panel of judges found that the plaintiffs failed to demonstrate injury as a result of New York City's implementation of the tax.

November 6 - CNN

A road in north eastern Nebraska with power lines on either side, and grassy fields.

Eastern Nebraska is running out of electricity

Data centers and electrification are straining eastern Nebraska’s grid, throttling economic development.

November 6 - Grist

FREE Course: Walkable City 1: Why Walkability?

After describing his path towards focusing on walkability as the essence of good planning, Jeff Speck marches through his five principal reasons for making more walkable places.

Reinventing Malls: Planning Alchemy—Turning Gray Fields Into Gold

The course focuses on the opportunities and imperatives that shape reinvention of mall sites.