The equity of urban forest ecosystem services and benefits in the Bronx, NY

Abstract

Trees provide important ecosystem services and benefits, with some, such as air pollutant and heat reductions, being linked to improved human health and well-being. The uneven distribution of tree cover in urban areas and subsequently the ecosystem services and benefits it provides has potential implications related to environmental justice, especially if disadvantaged socio-demographic or socio-economic and marginalized communities lack these services and benefits. This study explores the distribution of ecosystem services and benefits provided by tree cover in the Bronx, NY. Utilizing census block group specific spatial datasets, we employ a Mann-Kendall trend test and the Sen slope estimator to describe the relationship between median income, per capita income, percent minorities, population density, poverty percent and total educational attainment, and carbon storage and sequestration, stormwater runoff reduction, air pollutant removal and heat index reduction ecosystem services and benefits for 2010 tree cover conditions. We explore the equality in ecosystem service and benefit distributions across socio-demographic and socio-economic subgroups using the Atkinson inequality and Theil entropy indices decomposed into within and between subgroup inequalities for each ecosystem service and benefit. These inequality indices allow us to better assess current inequalities and work to achieve greater equity in the distribution of ecosystem services. Using population and ecosystem service data, all ecosystem services and benefits appear to be unequally and inequitably distributed in the Bronx, with disadvantaged socio-demographic and socio-economic block groups receiving disproportionately lower ecosystem services from urban trees. The vast majority of the inequality is explained by variations within each socio-demographic and socio-economic subgroup rather than variations between subgroups. To reduce this inequity, efforts should be made to strategically increase services and benefits by initially targeting disadvantaged block groups with extremely low tree cover.