Influence of Tree Planting Program Characteristics on Environmental Justice Outcomes

Urban trees provide a variety of benefits to human physical and mental health. However, prior research has shown that urban tree canopy is unevenly distributed; areas with lower household incomes or higher proportions of racial or ethnic minorities tend to have less canopy. Urban tree benefits are largely spatially-dependent, so this disparity has a disproportionate impact on these communities, which are additionally subject to higher rates of health problems. Planting programs are a common way that municipal and nonprofit urban forest organizations attempt to increase canopy in cities. Increasing canopy in underserved communities is a commonly desired outcome, but which of the wide range of programmatic strategies currently employed are more likely to result in success? This research uses interviews with planting program administrators, spatially referenced planting data, and demographic data for six U.S. cities in order to connect planting program design elements to equity outcomes. I developed a planting program taxonomy to provide a framework for classifying and comparing programs based on their operational characteristics, and used it along with planting location data to identify programs that had the greatest reach into low-income and minority area. I found that highly integrated partnerships between nonprofit and municipal entities, reduced planting responsibility for property owners, and concentrated plantings that utilize public property locations to a high degree are likely to improve program penetration into low-income and minority areas. These findings provide urban forestry practitioners with guidance on how to more successfully align planting program design with equity outcomes.