Monitoring and modeling changes in street tree communities over time

2019 | Robert Fahey, PhD, University of Connecticut

The project addresses a fundamental question for municipal forest management: how do street tree communities change over time? The project will focus on re-measuring plots established in 2015 in Philadelphia, PA to address two research goals using observations of street tree mortality, new plantings, growth, and health. First, models of street tree community change will be developed based on tree growth and death rates for size classes of trees. The models will be used to “grow” the urban forest and project future street tree population changes over a five- to twenty-year time horizon using scenarios of increased or decreased tree mortality and planting. Second, the effect of site and tree characteristics on street tree mortality and health will be assessed. Variables considered include initial tree size and health, species drought tolerance, site type, land use, presence of stewardship groups, human population density, median housing value, and median income. The analyses will characterize how the street trees of Philadelphia have changed over a five-year period, and allow prediction of future changes. This study has direct application to municipal forestry, supporting practitioners as they manage street tree communities with an intent to shape the future characteristics of the system. The project will produce a freely available toolkit that will enable municipal foresters in other cities to “grow” their urban forests with local inventory data.

Year: 2019

Funding Duration: 3 years

Grant Program: Hyland R. Johns Grant

Grant Title: Monitoring and modeling changes in street tree communities over time

Principal Investigator: Dr. Robert Fahey

Co-Principal Investigators: Lara Roman (USDA Forest Service Northern Research Station) and Jason Grabowsky (Rutgers University)

Key words: communities, street trees, monitoring, modeling

Peer Reviewed Publications from Grant:

General Audience/Trade Publications:

Professional Presentations:

For more information on this project, contact the researcher via TREE Fund at