Return to Vol. 6 Issue 2, April 2011

Mapping Philadelphia’s Trees at

By in Vol. 6 Issue 2, April 2011

On April 29, as part of Technically Philly’s Philly Tech Week, we will launch, a wiki-style, web-based geography-enabled urban tree inventory application that enables the general public to collaborate with Philadelphia Parks and Recreation, the Pennsylvania Horticultural Society (PHS), and other local groups in a joint effort to map, tend, and preserve Philly’s trees.

Philadelphia, like many American cities, has a wealth of urban street trees.  These hard-working trees line the streets of Philadelphia and help improve our neighborhoods by adding shade, bettering air quality, assisting with stormwater runoff, and generally improving the look and feel of our communities.  Despite their clear benefits, calculating the exact number of street trees has been a difficult and time-consuming process for many municipalities.  With limited resources and other necessary activities, how can a city find time to inventory every single tree?

We’re hoping to make the tree inventory process easier for the City of Philadelphia starting April 29.  As part of that day’s Green Tech Showcase at Philly Tech Week, we’ll be joining with our partners Philadelphia Parks and Recreation, PHS, and DVRPC to introduce PhillyTreeMap and encourage the people of Philadelphia to join the process of growing a green future together.

Why bother with a tree inventory?  Having an up-to-date inventory enables organizations to better maintain these important trees and plan future planting and renewal efforts.  To get started with the process, we’ve loaded the database with existing inventories from PHS, the City, and the Township of Lower Merion and created a series of checks to eliminate duplicate entries.  Each tree is associated with a particular location and may include information such as species, diameter, a photograph of the tree, and yearly eco impact numbers. will be available on April 29

To contribute to the inventory, users can create a free account and then edit existing tree details, upload an image of the tree, or add a new tree to the system.  They can also get help to identify the species of a tree using the handy tree key available on the site.  All changes are available to the general public although a group of trained administrators will review the site for inaccurate or inappropriate changes.  The database will accept additions for trees within the larger thirteen county/three state region surrounding Philadelphia, the same region as the recently announced Plant One Million campaign.

Collaboration is an important part of PhillyTreeMap. The website is built on open source code contributed by the Urban Forest Map project in San Francisco, a group with whom Azavea will continue to work in the future. We hope that the combination of members of the public, non-profit groups, and local government and businesses will result in a dynamic and exciting project that leads to a more complete tree inventory for our nation.

Azavea developed PhillyTreeMap using funding received from the USDA National Institute of Food and Agriculture as part of the Small Business Innovation Research Program (Grant Number 2010-33610-20937).  PhillyTreeMap serves as the prototype of a larger OpenTreeMap project for which we’re currently pursuing further grants in order to implement additional features that may be of use to other municipalities nationwide.