Gentrification and urban forest structure and stress: Lessons from two cities

Urban trees must be both present and healthy to provide vital ecosystem services, but there are documented inequities in tree canopy cover within U.S. cities. These inequities, like cities themselves, are not static. However, the influence of urban social and physical change itself on urban tree canopy structure, and especially tree stress, is poorly understood, limiting the efficacy of long-term urban forest planning. Gentrification, the process by which investments in a neighborhood displace low-income residents, can disrupt both social relationships and the physical space of the neighborhood, and can thus influence patterns of tree planting, investment in tree care, and likelihood of tree damage. Here, we quantify patterns in the number, diversity, and stress of street trees stress across neighborhoods in two regions experiencing gentrification: the West Side of Chicago, IL and Durham, NC. We found variation in the number, diversity and stress of street trees, including numerous regions where more than a third of street trees had high stress. However, the results do not indicate a uniform relationship between social and physical disruption and the number, diversity, or stress of trees. Our results and supplementary case study analysis hint at the role of municipal policies alongside non-governmental and community actions for especially tree planting practices and potentially tree care. Research and management that considers the role of actors such as residents, local non-profits, and city governments together may be better able to adjust management based on local conditions to cultivate a more resilient urban street tree population • Proportion of trees with high stress reached as high as 59%, but varied within cities • Social and physical disruption was not uniformly associated with negative outcomes • Tree number and stress are consistent with city policies (especially for construction) • Species diversity consistent with influence of city policies and/or landowners • Mixed methods needed to clarify influence of municipal and non-governmental actors