Understanding Macro-scale Patterns in Urban Tree Canopy and Inequity across Socio-cultural and Biophysical Regions

Urban forests provide a variety of ecosystem services that influence environmental and social welfare within developed areas. Prior studies have evaluated the effects of inequitable distribution of urban tree canopy (UTC) on ecological and social benefits, leading to inequalities within individual cities. However, it is not well established how such relationships vary among urban areas in different biophysical and socio-cultural regions. The objective of our study was to identify regional and continental trends in the relationships of UTC with socioeconomic/ demographic factors and characteristics of urban regions (e.g., development patterns, timing). To address our objective, we utilized iTree Landscape and US Census data to develop a data set of census block group level UTC-related response variables (e.g., percent UTC, inequity in UTC) and socio-economic/demographic predictor variables (e.g., median income, inequality in median income) for forty U.S. cities, spanning several different biophysical and sociocultural regions. We utilized multiple regression analysis in an information-theoretic model selection framework to analyze relationships among UTC, ecosystem benefits, socioeconomic, and demographic predictor variables and then evaluated how these relationships varied among cities within and among ecoregions and socio-cultural regions. Our results illustrated a strong negative correlation between UTC and UTC inequity, as UTC decreases, UTC inequity increases. Patterns in socioeconomic predictors of UTC emerged among biophysical and sociocultural regions, indicating socio-ecological factors influence UTC inequities