Missing the Urban Forest for the Trees: Re-thinking the “Tree City USA” Program as a Catalyst for Sustainable Communities

David G. Engel, Gettysburg College
Dennis L. Hicks, Gettysburg College
Umar Tunkara, Gettysburg College

Environmental Studies Senior Thesis


Urban forests can play a major role in achieving all three pillars of sustainability in towns and communities. Not only can they offer a clean and healthy environment, they have been shown to render wide-ranging economic and public health benefits. One popular program for catalyzing support for urban forestry is the Tree City USA program run by the Arbor Day Foundation. This study examines the effectiveness of the Tree City USA program in realizing the goals of sustainable communities through a comparative assessment of two Central Pennsylvania towns: Carlisle, which is a Tree City USA community and Gettysburg, which is not. Using the USDA Forest Service’s i-Tree software we characterized the urban forests in Carlisle and Gettysburg using data collected form 109 and 114 randomized plots respectively. We estimated forest impacts in terms of carbon sequestration, air pollution abatement, and storm water runoff. We also calculated estimates of other economic and public health benefits. Results show striking similarities between the urban forests of Gettysburg and Carlisle, with Gettysburg actually showing slightly greater benefits. These findings suggest there may be a more robust way of defining and promoting the Tree City USA program that uses more precise quantitative measures and includes outcome based evidence. The Engel-Hicks-Tunkara model (or EH-Tree!) program is offered for consideration.