San Francisco’s open-source tree maps

Trees are important assets – not just for forests, but also for cities. In the small San Francisco suburb where I live, the city government is adamant that if you have to cut down a tree, you have to justify it with a good reason (like, the tree is sick and dying), and you have to replace it with another one.

The City of San Francisco, a few minutes to the north, takes its arboreal assets seriously, and this month embarked on an ambitious urban forest mapping project to inventory and map all the trees within the city limits. Two organizations, the city’s Bureau of Urban Forestry and the non-profit Friends of the Urban Forest, are helping the city with this – and they’re using interesting software tools, based on open-source software.

The software that San Francisco is using is called STRATUM, or Street Tree Resource Analysis Tool for Urban Forest Managers – that’s a mouthful. STRATUM was build by the U.S.D.A. Forest Service Center at U.C. Davis. It’s based on MapGuide Open Source, an LGPL-licensed “corporate” open source program started by Autodesk. The company spun the open source project out of a commercial version of the product. The project is run by the Open Source Geospatial Foundation, which Autodesk set up and exercises a great deal of influence over (if not outright control).

San Francisco isn’t the only city to inventory its trees using STRATUM; others include Chicago, Fort Collins, Colo. and Modesto, Calif. However, it’s the first one I heard about, and because it’s local it’s more interesting to write about. San Francisco’s trees, not only in Golden Gate Park and the Presidio, but also in greenways and neighborhoods all around the City, are as much as part of its charm as the Golden Gate Bridge, Fisherman’s Wharf, cable cars and famously crazy crooked streets.

The urban forest map is available to everyone, not just to the San Francisco City government. Anyone can search for trees by species, address, neighborhood, planting date of the tree, and other factors. The Web-based map itself is very visual and interactive, and you can select different overlays that show soil conditions, the location of water sources and parks, who put the tree there (such as different non-profits or the city itself). You can also overlay satellite images or elevation lines. You’re even supposed to be able to use the STRATUM application to communicate back to the City, such as if you find that there’s a problem with a tree, though I couldn’t get that to work.

In my exploring the application, it seems a bit buggy, and occasionally goes unresponsive. Attempts to pan the map by click-and-drag, or learn information about an object by hovering the mouse pointer, did not work properly. The overlays also didn’t work consistently. With luck, the bugs will get worked out soon.

Despite those “version 1.0” flaws, it’s a pleasant change to encounter open-source successes that are applications, not infrastructure or software developer tools. Normally, we see the likes of Linux, Eclipse, NetBeans, Apache Tomcat, Hibernate and so-on. It’s good to see examples of how ordinary people can use open source software.