Design for Living: New York’s urban tree map

Individual details for a New York tree.

For the last seven years, New York has had an interactive tree map. Every street tree in the five boroughs is identified by a dot. Click on one of them, and you get the tree’s history, current status and ecological contribution, along with botanical information about the species, the nearest address and a photo. Last year, 150,000 trees in parks were added.

It’s a world first. All up, the New York City Tree Map contains about 800,000 trees.

The dots are colour-coded for each species and sized to show trunk circumference. The map lists each tree’s contributions to stormwater interception, removing air pollutants, conserving energy and consuming carbon dioxide. It shows the annual financial value of all that.

You can also access this data in larger units: on a neighbourhood or borough-wide basis. Zoom in for particular details, zoom out to see the patterns of tree cover in different parts of the city. The largest borough, Queens, has the most mapped trees (290,000), followed by Brooklyn (228,000). On Manhattan Island, there are more trees south of Union Square, despite its being very built up, than there are in the Harlem precincts, with a roughly similar size.

Wide detail of the New York Tree Map.

The map and its data bring the ecological benefits of trees into stark relief. A single large tree might be sequestering 25,000 tonnes of carbon, lowering energy needs in nearby buildings and in general providing over half a million dollars’ worth of benefits to the city.

The message is plain: the “urban forest”, or “urban ngahere”, as it’s called in Auckland, has the potential to make a very substantial contribution to the quality and cost of living in cities, not to mention to fighting climate change.

Gathering the data was the work of 2300 volunteers, working under the direction of NYC Parks and Recreation. And the voluntary work continues: if you water a tree or clean up around it, you can input that information to the database. If a tree needs expert attention, you can log that, too, or even get involved with one of the local groups that train residents in tree care. The map has become, like the trees themselves, a tool for building communities.

Trees line a street in Greenwich Village, Manhattan.

Central Park, as shown in the updated New York Tree Map.

Design for Living appears weekly in Canvas magazine.