STREET TREE EQUITY: UNDERSTANDING SOCIOECONOMIC AND ZONING FACTORS OF STREET TREE DISTRIBUTION IN THE CITY OF LOS ANGELES, CALIFORNIA

Abstract

Urban tree canopy (UTC) serves a critical role in the health and well-being of city inhabitants. The city of Los Angeles is amid a campaign to install 90,000 new trees and increase tree canopy by at least 50% in low-income areas. Street trees play a pivotal role in the composition of the urban tree canopy as it occurs in the public realm. This study seeks to determine how street trees are distributed in the City of Los Angles based on socioeconomic and zoning variables. A tree index value was calculated for each census block group and tested against 37 socioeconomic and zoning factors as well as historic HOLC redline designations. This study then used regression analysis to approximate a relationship between the explanatory factors, and the dependent variable of the calculated street tree index. Exploratory regression identified substantial positive relationships between tree index values and the significant explanatory variables of the Asian or Pacific Islander household language, associate or bachelor’s degree education attainment, commute by public transportation or walking, and Spanish household language. There were negative relationships between the tree index and the significant explanatory variables of population density, the Black or African American population, the population at or below the poverty line, Indo-European household language, and renter-occupied housing. There was a positive relationship between the tree index and areas zoned as residential only. A negative relationship existed for areas zoned as open space, industrial, public facility, parking, and commercial. There was also a negative relationship for areas included in the city’s hillside zoning ordinance. Historically redlined areas with a grade of A, B, or C included an entirely positive relationship with the tree index, however, areas with a grade of D had a less robust positive relationship.

This study can aid the City of Los Angeles with prioritizing block groups for street tree planting or provide insight for future studies with a more robust set of variables.