Analyzing Environmental and Social Impacts of Urban Forestry Practices in Tacoma, WA with PlanIT Geo™

Urban forestry encompasses street trees, residential trees, park trees and greenbelt vegetation. Despite local groups’ efforts and trends in better forest management practices, there is an unequal distribution of urban forests and their associated ecosystem services across most of the United States. Evaluating canopy distribution is the first step to enable cities to better devote limited resources to marginalized communities, which often have additional equity concerns. Our project will help the urban forestry LLC, PlanIT Geo™, and their future clients in their urban forestry management plan recommendations and could increase the equitable dispersal of environmental benefits. In addressing the equity of Tacoma’s urban forests, we assessed trees' impacts on air quality and human health. We designed an equity index model to compare census block groups based on five indicators: canopy coverage, demographic, climate, air quality, and health. The air quality and health indicators were derived by analyzing PM_2.5 reduction through the amount of canopy coverage and the associated health benefits from improved air quality in Tacoma, WA. We then calculated individual indicator scores and a composite environmental equity score for each census block group in Tacoma. Conclusions reveal that there is an overall unequal tree canopy distribution in Tacoma and considering additional indicators broadens PlanIT Geo’s awareness of the most vulnerable communities in Tacoma. Through this analysis, we identified priority areas in need of intervention and environmental considerations to maximize socio-economic and environmental benefits while minimizing harm post-intervention.

Acknowledgements

PlanIT Geo™: Ian Hanou, Maegan Blansett

Bren School: James Frew, Associate Professor; Rachel Torres, PhD Candidate; Robert Heilmayr, Assistant Professor; Allison Horst, Lecturer; Sam Stevenson, Assistant Professor; Sarah Anderson, Professor; Steve Miley, IT Director

Michael Carey, City of Tacoma Environmental Services

PlanIT Geo™

American Community Survey

PurpleAir

USGS Earth Explorer

City Forest Credits

American Forests: Chris David, Ian Leahy