Trees grow on money: urban tree canopy cover and environmental justice

PLoS One. 2015 Apr 1;10(4):e0122051. doi: 10.1371/journal.pone.0122051. eCollection 2015.

Abstract

This study examines the distributional equity of urban tree canopy (UTC) cover for Baltimore, MD, Los Angeles, CA, New York, NY, Philadelphia, PA, Raleigh, NC, Sacramento, CA, and Washington, D.C. using high spatial resolution land cover data and census data. Data are analyzed at the Census Block Group levels using Spearman's correlation, ordinary least squares regression (OLS), and a spatial autoregressive model (SAR). Across all cities there is a strong positive correlation between UTC cover and median household income. Negative correlations between race and UTC cover exist in bivariate models for some cities, but they are generally not observed using multivariate regressions that include additional variables on income, education, and housing age. SAR models result in higher r-square values compared to the OLS models across all cities, suggesting that spatial autocorrelation is an important feature of our data. Similarities among cities can be found based on shared characteristics of climate, race/ethnicity, and size. Our findings suggest that a suite of variables, including income, contribute to the distribution of UTC cover. These findings can help target simultaneous strategies for UTC goals and environmental justice concerns.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cities
  • Environment
  • Humans
  • Plant Dispersal
  • Socioeconomic Factors
  • Trees*
  • United States
  • Urban Population
  • Urbanization

Grants and funding

Funding was provided by the National Center for Ecological Analysis and Synthesis, Project 12575 (http://www.nceas.ucsb.edu/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.