Urban tree networks are essential for the ecological resilience and character of cities. Street trees, specifically, are an important part of the urban forest, softening the harsh building-street interface and filtering the air between pedestrians and traffic. We use tree inventory data to measure street tree diversity in eight global cities, comparing the city center with the outer areas of the city.
We measure street tree networks against the 10/20/30 rule, which suggests an urban forest should be no more than 10% of one species, 20% of one genus, and 30% of one family. We also use diversity indices — the Shannon Index and Simpson Index — to account for the abundance and evenness of the species present in the city.

Learn which tree species, genus and family are predominant in each city, and explore tree diversity on the maps below, block by block, tree by tree.

select a city

Bologna, Italy
current cityother study citiesstreet trees meet benchmarkclose to benchmarkexceed benchmark

city center most abundant organisms

Species

London Plane
Platanus acerifolia

22.87%

0%10%20%30%40%50%60%70%species benchmark

 

Genus

Plane Trees
Platanus

23.05%

0%10%20%30%40%50%60%70%genus benchmark

 

Family

Plane Tree Family
Platanaceae

23.54%

0%10%20%30%40%50%60%70%family benchmark

outside city center

Species

European Nettle Tree
Celtis australis

16.01%

0%10%20%30%40%50%60%70%species benchmark

 

Genus

Nettle Trees
Celtis

16.01%

0%10%20%30%40%50%60%70%genus benchmark

 

Family

Hemp Plants
Cannabaceae

16.12%

0%10%20%30%40%50%60%70%family benchmark

Species Taxonomy

Species Diversity (Shannon Index)

Least Diverse

Most Diverse

Diversitree

Tree diversity, on a species-, genus-, and family-level, is an important factor in securing healthy urban forests and providing ecosystem services for billions of city dwellers. Using open-source data on global tree inventories, Diversitree examines (1) the diversity of species, genera, and family of urban street trees in eight cities internationally; (2) how they score on diversity benchmarks and indices; and (3) the diversity variation inside and outside of cities’ centers. Understanding street tree diversity and spatial variation patterns across cities internationally can offer needed evidence to back up heuristic benchmarks. The methodology and open-source data used in this study are intended to enable practitioners to better target tree diversity efforts.

Publication

Galle, N., Halpern, D., Nitoslawski, S., Duarte, F., Ratti, C., & Pilla, F. (2021). Mapping the diversity of street tree inventories across eight cities internationally using open data. Urban Forestry and Urban Greening.

Press Material

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The material on this website can be used freely in any publication provided that:

  1. 1. It is duly credited as a project by the MIT Institute.
  2. 2. A PDF copy of the publication is sent to senseable-press@mit.edu

Team

Carlo Ratti, Director
Nadina Galle, Research Lead
Dylan Halpern, Researcher + Visualization
Sophie Nitoslawki, Researcher
Fábio Duarte, Research Manager
Francesco Pilla, Research Advisor

Related Project

Treepedia

Diversitree is a research project of:

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This research received partial funding from the Connecting Nature project (Grant Agreement No. 730222) under the European Community’s Framework Program Horizon 2020.



For more information, please email senseable-contacts@mit.edu

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