Partnering to study Philadelphia’s ‘urban forest’

Conjure up an image of a forest. Chances are you’re imagining a vast tract of treed space seemingly untouched by humans. So why, then, did the U.S. Forest Service (USFS) open an office in the urban, heavily populated landscape of Philadelphia?

“Eighty percent of Americans live in urban areas, and urban natural resources are vital to environmental health and community well-being,” says Sarah Low, coordinator of the USFS’s Philadelphia Urban Field Station, which opened its doors in Center City a little more than one year ago. “Forest Service scientists study all angles of urban forestry, from the environmental benefits of trees to how they contribute to people’s health and happiness.”

Penn faculty and students have been integral players in the Field Station’s efforts to understand how trees in cities impact the surrounding air, water, climate, soils—and human beings, as well.

Soon after the station opened, it took a major step to engage local academics by offering a fellowship to six students in the Philadelphia area to conduct research related to the USFS mission of sustaining ecosystems to meet human needs.

Two Penn students, Anna Shipp and Shea Zwerver, won fellowships, earning financial and logistical support as well as mentorship from Forest Service scientists.

“I had a research idea already that fit perfectly with what the fellowship was geared toward,” says Shipp, who is part of Penn’s Master of Environmental Studies program. “The project I’m working on is about South Philly residents’ perceptions of and preferences for urban trees and green spaces within their neighborhood.”

This research will form the capstone project for Shipp’s master’s degree. She is just beginning to collect data, but her plan is to survey members of various community groups in South Philadelphia neighborhoods. She’ll have participants rank the type of green spaces they prefer, with possibilities ranging from tranquil sitting areas to community gardens. Shipp is hopeful that her results inform the city’s planning, including the mayor’s Greenworks Philadelphia initiative.

Charles Branas, an epidemiology professor in the Perelman School of Medicine, is also partnering with the Field Station to expand his research on how the city’s green spaces can impact residents’ health. Specifically, he has found that vacant lots “beautified” by planting trees and other vegetation were associated with reductions in gun violence in the surrounding area and, in some cases, lowered levels of stress and fear and increased exercise participation in area residents.

The Pennsylvania Horticultural Society (PHS) was a partner in this study, as they conducted the vacant lot clean-up and planting efforts. It was through the PHS that Branas connected to the USFS.

Now, Branas is welcoming a new postdoctoral researcher in his lab, Michelle Kondo, who will be jointly funded by the National Institutes of Health and the USFS. Kondo, who is currently finishing a postdoctoral fellowship at the School of Social Policy & Practice, will be measuring the effect of vegetation on air pollution and tying that to health outcomes in Philadelphia neighborhoods.

“For example, we want to be able to monitor areas with and without vegetation,” says Kondo. “We know that near roadways with a lot of traffic there’s going to be particle and gas pollution within a certain distance of that roadway, but one question is whether and how vegetation can reduce the attenuation of that pollution.”

Obtaining this kind of spatial data and presenting it in an informative way is the task of another Penn entity, the Cartographic Modeling Laboratory (CML), which is a partnership among the schools of Medicine, Design, and Social Policy & Practice.

“We support researchers across Penn’s campus who are interested in bringing a visual aspect or spatial aspect to their research,” says Tara Jackson, the CML’s executive director. That includes Branas’s work; the CML compiled data on crime statistics, parcel size, code violations, and other features of vacant lots across the city, helping lend weight to his analysis.

There are still more connections between the Field Station and Penn. Wharton’s Susan Wachter, the Richard B. Worley Professor of Financial Management and professor of real estate and finance who is also co-director of Penn’s Institute for Urban Research, has previously studied how tree planting influences home values in the Philadelphia area. Moving forward, she will be working with Penn colleagues, the Forest Service, and other partners to explore more broadly how trees and additional “green infrastructure” provide ecosystem services to the city’s population. Plans are in progress to host a workshop at Penn this spring, in conjunction with the USFS and the U.S. Geological Survey, which will further delve into those topics.

A year in, and with the Field Station gearing up to select its next round of fellowship recipients, it appears that the Penn-USFS collaborations will only grow.

“We’re very pleased to have this connection with the Forest Service and we hope it continues into the far future,“ says Branas.

Field Service