What is a Tree Worth? An Appraisal of the University of Pennsylvania’s Tree Population

In 2018, the University of Pennsylvania received a level 2 arboretum accreditation. This new status provides incentive for establishing rigorous tree protection protocols and policies. To preserve and protect a healthy urban forest, it is necessary to develop a plant health care and maintenance program, which can be a costly process. By appraising Penn’s campus tree population, and by determining the monetary benefits trees provide through their environmental and ecosystem services, we can advocate for a tree care budget that is consistent with the value of the asset. We used methods outlined in the Council for Tree and Landscape Appraisal’s (CTLA) Guide to Plant Appraisal to appraise a sample of Penn’s campus trees. This process involved collecting data on the size, species, condition, and location of trees around campus. Additionally, an estimate of the environmental and ecosystem services rendered by these trees was generated using the i-Tree Eco program. The appraised value for Penn’s campus trees was $12.6 million dollars and the environmental benefits totaled approximately $161,000 dollars. The figure for environmental benefits is likely an underestimate, because we only included the minimum data required to run the i-Tree model. In the future, including interpretative signage on or around trees that mentions their appraised value and environmental benefits, may assist in educating the Penn and greater Philadelphia communities about the importance of trees in urban environments.