In April, Philadelphia launched PhillyTreeMap.org, a wiki-inspired, geographic urban tree inventory web application that collects data from the public to map trees in the 13-county, three-state region. The website invites residents to document the location, species and other data about the region's trees, supplementing resources available from local governments and non-profit groups to track and expand the region's urban forest.

The Philadelphia Parks & Recreation Department, the Pennsylvania Horticultural Society (PHS) and the Delaware Valley Regional Planning Commission worked with locally based geospatial software development firm Azavea to create the application, starting with the city's existing data for more than 177,000 trees. The website complements PHS's Plant One Million project, which is encouraging residents to plant trees and to use PhillyTreeMap to record information about their recently planted trees or expand on information about existing trees. The site can be searched by criteria, including location, species, diameter and date planted.

After completing a free registration, users can add trees to the system, edit or add to existing tree records, and upload tree images. All changes are immediately visible in the system, but a group of administrators at PHS and the parks department review changes and new entries to ensure accuracy.

PhillyTreeMap also estimates the impact of each tree on the urban environment, including stormwater interception, carbon sequestration, air quality and other metrics. The economic benefits are calculated using iTree, an urban forestry analysis and benefits assessment software suite developed by the USDA Forest Service, and are automatically updated each time a tree is updated in the inventory.

The application was built on open source code contributed by San Francisco-based Urban Ecos and Umbrella Consulting for the Urban Forest Map project in San Francisco. In July, the source code for PhillyTreeMap was released to the public under the name "OpenTreeMap" to allow residents, students and nonprofit organizations in other cities to work with their local agencies to map and preserve the urban forest. The code is freely available at https://github.com/azavea/OpenTreeMap.

PhillyTreeMap.org was developed using funding from the USDA National Institute of Food and Agriculture as part of the Small Business Innovation Research Program. The city and PHS invested in-kind staff time to prepare and assemble data, and Azavea paid for the cost of developing the PhillyTreeMap implementation of OpenTreeMap.

Depending on funding, PhillyTreeMap may be expanded in the future to include a smart phone and tablet version, social media integration, tools to support competitions and other methods for feeding the data into additional systems.

Project: Engaging residents in urban tree mapping
Jurisdiction: Philadelphia
Agencies: Philadelphia Parks & Recreation Department, Pennsylvania Horticultural Society and the Delaware Valley Regional Planning Commission
Vendor: Philadelphia-based Azavea
Date launched: April 2011