The canopy and the community: Quantifying the disparity of urban forest benefits and vulnerability in Maryland

Urban forests deliver essential ecosystem services, such as carbon storage, air-pollution removal, and stormwater regulation, that support environmental quality and public health. Yet these benefits are unevenly distributed, exacerbating inequities between high- and low-vulnerability communities. The primary goal of this study was twofold: (1) to quantify the tract-level distribution of key urban forest ecosystem services (ES) across Maryland's 34 urban areas, and (2) to statistically evaluate the extent to which their provision is tied to social vulnerability. Using GIS-based spatial analysis, i-Tree Landscape estimates, and 2020 U.S. Census tract boundaries, we mapped tree canopy cover, carbon storage and sequestration, air-pollution removal, transpiration, rainfall interception, and avoided runoff (volume and value). Social vulnerability classifications were derived from Social Vulnerability Index (SVI) metrics based on U.S. Census Bureau’s Community Resilience Estimates (CRE). Disparities were quantified using Kruskal–Wallis and Tukey’s post-hoc tests to compare ES provision across three CRE vulnerability classes. Results indicate that low-vulnerability communities consistently exhibit higher tree canopy cover and greater ecosystem service benefits, while highly vulnerable communities experience reduced canopy cover and diminished access to these services. Significant associations between SVI metrics and ES distribution highlight persistent socio-environmental disparities in urban forestry. These findings demonstrate unequal distribution of ecosystem service provision, with the most vulnerable communities receiving the fewest benefits. This tract-level framework provides a replicable and scalable tool for assessing equity in urban forest benefits, supporting prioritization of urban greening investments, equitable strategies, and policy interventions aimed at promoting more inclusive resilient urban landscapes and restoring ecosystem benefits.