Trees Grow on Money: Urban Tree Canopy Cover and Environmental Justice

都市の樹冠率（ＵＴＣ）と所得水準の相関関係に関するKirsten Schwarz,の研究レポートの話題。

米国の主要都市の樹木（樹冠率）と貧困や人種の関係をＧＩＳで解析し、住民の所得の差が樹木植栽、維持管理に影響し樹冠率の差に結び付いているのではないかと指摘しています。

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.

□参考サイト

Schwarz K, Fragkias M, Boone CG, Zhou W, McHale M, et al. (2015) Trees Grow on Money: Urban Tree Canopy Cover and Environmental Justice. PLoS ONE