Traditional approaches to urban development often do not account for, or recognize, the role of ecosystem services and the benefits these services provide to the health and well-being of city residents. Without such accounting, urban ecosystem services are likely to be degraded over time, with negative consequences for the sustainability of cities and the well-being of their residents (Millennium Ecosystem Assessment, 2005; Hirsch, 2008). On May 23, 2013, the Spatial Integration Laboratory for Urban Systems (SILUS), a collaboration between the U.S. Geological Survey (USGS) Science and Decisions Center and the Wharton GIS Lab, convened a one-day symposium—Urban Ecosystem Services and Decision Making: A Green Philadelphia—at the University of Pennsylvania in Philadelphia, Pennsylvania, to examine the role of green infrastructure in the environmental, economic, and social well-being of cities. Cosponsored by the USGS and the Penn Institute for Urban Research (Penn IUR), the symposium brought together policymakers, practitioners, and researchers from a range of disciplines to advance a research agenda on the use of science in public decision making to inform investment in green infrastructure and ecosystem services in urban areas.

The city of Philadelphia has recently implemented a program designed to sustain urban ecosystem services and advance the use of green infrastructure. In 2009, the Philadelphia Mayor’s Office of Sustainability launched its Greenworks plan, establishing a citywide sustainability strategy. Major contributions towards its goals are being implemented in coordination with the Philadelphia Water Department (PWD). The Green City, Clean Waters initiative, the city’s nationally recognized stormwater management plan, was signed into action with the U.S. Environmental Protection Agency (EPA) in April 2012. The plan outlines a 25-year strategy to use green infrastructure to protect and improve the city’s watershed. Widespread support for the plan marks a citywide effort to factor environmental quality concerns into the city’s strategic planning, choosing to replace expensive and aging grey infrastructure, with innovative and resilient green infrastructure.

The symposium focused on these city of Philadelphia initiatives and also on two new Federal- local partnership programs: America’s Great Outdoors, initiated to promote conservation and recreation, and the Urban Waters Federal Partnership, a multiagency effort to reconnect urban communities to their waterways.

A second goal of the symposium was to advance a research agenda on urban ecosystem services. While there has been considerable work on ecosystem services, the discussion of the benefits provided by urban ecosystems is not as developed. Benefits range from improved water and air quality to quality of life gains, including aesthetic and recreational considerations. There is also need for additional focused research toward furthering the understanding of the multiple indirect benefits provided by urban ecosystem services (Bolund and Hunhammar, 1999). Moreover, there is a need for a greater understanding of how best to inform local decision making in this area, as local decision makers in cities across the country are increasingly recognizing the importance of developing sustainability measures for their immediate and long-term planning (United States Conference of Mayors, 2005).

Approaching these local and regional plans from a holistic perspective has become a guiding principle of sustainability and resiliency. Therefore, there is a need to better understand the gains that have been achieved and to advance a research agenda on ecosystem services going forward. The day’s program included presentations on greening initiatives from the Philadelphia’s Mayor’s Office of Sustainability, as well as discussion about using an urban ecosystem services framework to evaluate these initiatives. Panel sessions included discussion of the Green City, Clean Waters initiative; a dialogue about the management of urban trees and green space; and a conversation addressing the needs for future research.