Analysis of private residential urban forest structure and management in Bloomington, Indiana: A social-ecological systems (SES) perspective

Background/Question/Methods

Tree cover in urban areas of the United States is declining, bringing to light concerns for the sustainability of urban forests. One explanation for this decline is that most urban trees are located on private property where private households have few incentives to produce public benefits. From a social-ecological system (SES) perspective, institutional factors (such as municipal policies or neighborhood norms) can incentivize sustainable urban forest management (UFM), but the biophysical and social contexts are equally influential. Thus, we ask: What SES characteristics influence the structure and function of the private urban forest? What motivates households in the management of their urban trees? To answer these questions, we surveyed owner-occupied households within 14 residential associations (neighborhood and home-owner) in the city of Bloomington, Indiana regarding their individual tree management and the impact of city and association rules and norms upon it. In addition, we inventoried private and public right-of-way (PROW) trees on 106 residential parcels that had returned questionnaires.  Utilizing the SES framework and theory drawn from UFM and SES literature, we link biophysical data with social and institutional data to identify factors affecting the sustainability of residential urban forests.

Results/Conclusions

Preliminary results demonstrate that tree maintenance occurred more often on parcels with fewer trees, and the higher the proportion of trees maintained, the better the average tree condition per parcel. In addition, tree maintenance on a parcel was negatively correlated with invasive trees species abundance. We found significant differences in the management of private and PROW trees relating to institutional differences between the property types—more than 70% of PROW trees were maintained, while less than half of private trees were maintained.  There were significant differences between residential associations in terms of tree abundance, species richness, and basal area. Overall, tree structure across associations was largely correlated with age of housing development. Ongoing analysis will allow complete results to be presented including additional linkages between parcel-level survey data and biophysical results.