Manhattan Tree Map: A Data Through Design exhibit


By Hermann Zschiegner, TWO-N

1,000,000 Trees

On January 9th of 2017, the official Twitter account of MillionTreesNYC (@MillionTreesNYC) announced that they had reached the initiative’s ambitious goal to plant and care for one million new trees across the City's five boroughs. Starting in April of 2007 as a joint venture between the city’s Parks Department, private organizations, residents, and community organizations, it took almost 10 years to increase New York City’s urban tree population by an astounding 20%.

As of today, there are 5.2 million trees and 168 different species in New York City, providing numerous environmental, economic, and social benefits for all. Trees have been shown to lower surface air temperatures by providing shade, absorb and retain stormwater, and remove air pollutants.

The Parks Department, with the help of legions of volunteers, conducts a decennial census of the City's street trees: those that line sidewalks and roads, as opposed to those inside parks. The 2015 Street Tree Census, a dataset publicly available on the NYC Open Data Portal provides an inventory of the 683,788 street trees across all five New York City boroughs. Each tree is geo-coded and classified by its species, health, and maturity. This data is the backbone of the Park Department’s internal forestry management database.

Raw data

At TWO-N we almost exclusively focus on interactive, browser-based data visualizations. We are graphic designers and coders – visual communicators – encoding data as visual objects (dots, lines, bars) and creating a framework to dynamically interact with the data (filter, zoom, animate). We deliver a visual representation and give form to data, providing a sensory framework to experience intangible or nonmaterial information.

With our submission for the Data Through Design art exhibit we decided to take a different approach, and we designed a data visualization that was interactive and haptic in nature. The challenge was to create a touchable, physical object that would embody the data and allow for a different way to interact with it.

We picked the NYC Street Tree Census data as our data source, driven by the somewhat poetic idea to build this data object out of the raw data - wood samples - described in the dataset. We wanted to enable the audience to engage with the “data” by touching a real wood/data artifact, allowing a user to smell the wood, feel its weight and texture, and explore the subtle differences in color and density.

Tree map

We decided to create a three dimensional map of Manhattan – a hybrid of a choropleth map, a bar chart, and an interactive game – that would offer a chance to experience some of the tree census data. Each neighborhood of Manhattan is represented by a removable wooden block, with the height of each block signifying the total amount of trees planted during the Million Tree Initiative. The wood used for each block is based on the most predominant tree species found in each neighborhood. The resulting object thus encodes 3 individual data-points from the source data:

1. Block outline > area (shape) for each neighborhood

2. Block height > total number of street trees for each neighborhood

3. Block material > main tree species for each neighborhood

The wooden blocks sit on a base with additional information laser-cut into the board, with each individual tree printed onto the base to be uncovered as a user removes a city-block from the model.

Data (wood) processing & sourcing

While we are used to sourcing and cleaning data as part of our everyday workflow, sourcing the wood samples for our model quickly turned out to be way more challenging as anticipated.

Not surprisingly, the street trees used in the Million Tree project were chosen for fast growth, aesthetics, and ability to withstand the urban setting. However, most of these trees do not have a wide commercial market, including the number one tree planted since 1995: the Honeylocust.

Honeylocusts produce a high quality, durable wood that polishes well, but the tree does not grow in sufficient numbers to support a bulk industry.

In addition to the Honeylocust, we needed samples of Callery Pear, London Planetree, Pin Oak, and the Japanese Zelkova.

It took repeated trips around a number of lumberyards and wood specialists to finally find a source for the wood samples we needed for our project.


First, we had to mill the wooden planks to smooth the surface so they could be glued together later to achieve the different heights for each block. The height for the various blocks varied between 4-inches (Upper West Side) to 1/3-inch for the 447 trees in Stuyvesant Town.

The shape of each neighbourhood was then CNC-ed out of the various wood samples and then glued to size.

Finally, each block was hand sanded and oiled for a smooth feel to the touch.

The base for the wood blocks was made from white melamine laminated MDF with the name and predominant trees for each neighborhood laser-engraved onto the surface. All 65,423 individual trees were printed on vinyl and applied to a plywood baseboard.

Finally, all pieces were ready for assembly.

Data Through Design

Our Manhattan Tree Map project was commissioned for the Data Through Design art exhibition, part of the ongoing Open Data Week. The exhibition is co-organized by the Pratt SAVI, CARTO, Enigma, and will be hosted at the Made in NY Media Center until 10 March 2018.

Project team

Hermann Zschiegner – Creative Director - TWO-N,Inc

Katrin Bichler – Lead Designer

Alec Barrett – Data Analysis

Natalie Erdem – Project Manager

Nodus Living – Wood Fabricator

Singh Hardwood – Wood Source

Ponoko – Laser Cutting  

About the author

Hermann Zschiegner is the principal of TWO-N, a New York based data visualization design agency. His obsession for visualizing data, combined with his passion for interaction design, is rooted in his background in Architecture. For the past 15 years he has designed data-driven user interfaces and visualizations for a number of clients including Bloomberg, the New York Stock Exchange, and the NBA.

In addition to his role as head of design at TWO-N he published a number of Artist Books and his work was shown at Rencontres d’Arles, the Cleveland Museum of Art, the Gagoisan Gallery in New York and Paris, the FotoMuseum in Antwerpen, as well as at the Museum Brandhorst in Munich.

Visit the exhibit's page here.