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You are here: NRS Home / Research Programs /Urban Natural Resources Stewardship / Monitoring and assessment of urban forests and trees / UFORE/i-Tree Eco Analysis of Chicago’s Urban Forest
Urban Natural Resources Stewardship

UFORE/i-Tree Eco Analysis of Chicago’s Urban Forest

[photo:] UFORE/i-Tree Eco crewmember using a laser range finder.Research Issue

Urban foresters, city planners, and municipal officials often lack a comprehensive overview of the city’s urban forest.  UFORE (now called i-Tree Eco) is a tool for collecting sampling data about a city’s trees and using it to estimate the urban forest’s composition, distribution, and effects on energy usage.

Our Research

The USDA Forest Service worked with the City of Chicago, the Chicago Park District, and WRD Environmental to conduct a UFORE (Urban FORest Effects, now called i-Tree Eco) analysis of Chicago's urban forest in the summer of 2007. The UFORE/i-Tree Eco model developed by the Forest Service uses on-the-ground sampling data to understand the composition of the urban forest and calculate the forest's impacts on air pollution and energy use.

UFORE/i-Tree Eco Chicago involved visiting 750 tenth-acre (0.1 acre) plots that were randomly distributed across all land uses and the entire city. Over a 4-month period, three dedicated field crews collected data on every tree >1 inch in diameter on every plot as well as more general plot information like ground cover and land use.

The UFORE/i-Tree Eco model estimated that there are about 3,585,000 trees in Chicago with canopies that cover about 17.2 percent of the city. The most common tree species are white ash, mulberry species, green ash, and tree-of-heaven. Chicago's urban forest currently stores about 716,000 tons of carbon. In addition, trees remove about 25,200 tons of carbon and about 888 tons of air pollution per year. Chicago’s trees reduce annual residential energy costs by an estimated $360,000 per year. The structural, or compensatory, value of Chicago’s urban forest is about $2.3 billion.

Many other cities and municipalities have also conducted UFORE/i-Tree Eco analyses.  Comparisons of the statistics from different cities and regions are available in the Chicago report.

Expected Outcomes

Information on the structure and functions of the urban forest can be used to inform urban forest management programs and to integrate urban forests within plans to improve environmental quality in the Chicago area.

Research Results

Nowak, D. J.; Hoehn III, R. E.; Crane, D. E.; Stevens, J. C.; Fisher, C. L. 2010. Assessing Urban Forest Effects and Values: Chicago’s Urban Forest. Resour. Bull. NRS-37. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 27 pp. 

Fisher, C. L.; Nowak, D. 2010. UFORE (i-Tree Eco) Analysis of Chicago. Illinois Trees (the Illinois Arborist Association Newsletter) 25(1): Winter, pp. 5, 8-9.

Research Participants

Principal Investigators

Research Partners

  • City of Chicago, Department of Environment
  • Chicago Park District
  • WRD Environmental
  • City of Chicago, Department of Streets and Sanitation, Bureau of Forestry

Last Modified: 10/18/2010

Featured Product

Nowak, D. J.; Hoehn III, R. E.; Crane, D. E.; Stevens, J. C.; Fisher, C. L. 2010. Assessing Urban Forest Effects and Values: Chicago’s Urban Forest. Resource Bulletin NRS-37. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 27 pp.