Tackling Tree Equity: Social and Economic Predictors of Urban Tree Canopy in Tucson, AZ

Abstract

Urban tree canopy provides essential ecosystem services to cities, from improving human wellbeing and health to reducing the urban heat island effect. However, previous studies have shown that tree canopy is often inequitably distributed. In 2019, Tucson was named the 3rd fastest-warming city in the United States. In response, the city government implemented the Tucson Million Trees initiative to help mitigate rising temperatures in the desert city. In an effort to make tree canopy more equitable, this study intends to determine what factors contribute to tree inequity in Tucson so that these factors can be considered in decision-making for tree-planting locations. Using existing data from the Pima Association of Governments, average tree canopy in each census block group was determined. This tree canopy data was tested against 26 variables commonly associated with tree inequity using exploratory regression. Regression analysis identified a seven-variable model with positive correlations between average tree canopy and population density, median household income, percent population with a bachelor’s degree, percent rental households, white population, and vacant households. The model showed negative correlations between tree canopy and percent population living alone. We hope that the results of this study can guide decision makers within the Tucson city government to prioritize block groups using the variables identified as predictors of tree canopy.