An analysis of trees in Philadelphia reveals that this city has about 2.1 million trees with canopies that cover 15.7 percent of the area. The most common tree species are black cherry, crabapple, and tree of heaven. The urban forest currently stores about 530,000 tons of carbon valued at $9.8 million. In addition, these trees remove about 16,100 tons of carbon per year ($297,000 per year) and about 802 tons of air pollution per year ($3.9 million per year). The structural, or compensatory, value is estimated at $1.8 billion. Information on the structure and functions of the urban forest can be used to improve and augment support for urban forest management programs and to integrate urban forests within plans to improve environmental quality in the Philadelphia area.

An analysis of trees in Washington, D.C. reveals that this city has about 1,928,000 trees with canopies that cover 28.6 percent of the area. The most common tree species are American beech, red maple, and boxelder. The urban forest currently store about 526,000 tons of carbon valued at $9.7 million. In addition, these trees remove about 16,200 tons of carbon per year ($299,000 per year) and about 540 tons of air pollution per year ($2.5 million per year). The structural, or compensatory, value is estimated at $3.6 billion. Information on the structure and functions of the urban forest can be used to improve and augment support for urban forest management programs and to integrate urban forests within plans to improve environmental quality in the Washington, D.C. area.

An analysis of trees in New York City reveals that this city has about 5.2 million trees with canopies that cover 20.9 percent of the area. The most common tree species are tree of heaven, black cherry, and sweetgum. The urban forest currently stores about 1.35 million tons of carbon valued at $24.9 million. In addition, these trees remove about 42,300 tons of carbon per year ($779,000 per year) and about 2,202 tons of air pollution per year ($10.6 million per year). The structural, or compensatory, value is estimated at $5.2 billion. Information on the structure and functions of the urban forest can be used to improve and augment support for urban forest management programs and to integrate urban forests within plans to improve environmental quality in the New York City area.

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.

Much of the ecological research in the past decades has focused on rural or wilderness areas. Today, however, ecological research has been taking place in our cities, where our everyday decisions can have profound effects on our environment. This research, or urban ecology, includes an important element, trees. Trees have had a variety of environmental benefits for our environment including the sequestering carbon, reducing urban heat island effects, providing vital habitat for wildlife, and making nature accessible. These benefits have important impacts on the physical, socio-economic, and mental health of humans as well. Being exposed to trees has been shown to enhance social cohesion, improve health and recreational opportunities, and increase real estate values. In order to gain more knowledge into this urban forestry, the National Academy of Sciences (NAS) held a workshop February 25-26, 2013. The workshop brought together more than 100 people with various interests in urban forestry research to share information and perspectives, foster communication across specific areas of ecosystem service research, and consider integrated approaches that cut across these realms. The workshop specifically examined current capabilities to characterize and quantify the benefits, key gaps in our understanding, the challenges of planning urban forests in a way that optimizes multiple ecosystem services and more. Urban Forestry: Toward an Ecosystem Services Research Agenda: A Workshop Summary presents an overview of the issues discussed by the workshop's breakout groups; summarizes presentations from the four panels which included Biophysical Services of the Urban Forest; and context for the study with introductory material from the workshop.