Assessing urban forest effects and values

An analysis of trees in Chicago, IL, reveals that the city has about 3,585,000 trees with canopies that cover 17.2 percent of the area. 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 valued at $14.8 million. In addition, these trees remove about 25,200 tons of carbon per year ($521,000 per year) and about 888 tons of air pollution per year ($6.4 million per year). Trees in Chicago are estimated to reduce annual residential energy costs by $360,000 per year. The structural, or compensatory, value is estimated at $2.3 billion. 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.