Sustainable Cities Institute:
Urban trees provide numerous environmental benefits such as mitigating air pollution and greenhouse gases, reducing storm water runoff and improving water quality, and decreasing the urban heat island effect.
Research has shown that trees and green space also have mental, physical, and social benefits. For example, trees, grass cover, and green space has been shown to create stronger bonds amongst neighbors, reduce violent and property crime, enhance the sense of safety, and promote more adult supervision of children in public spaces. Studies that have examined children from a range of groups suggest that green space plays an import role in helping children develop. For example, one study has shown that interaction with nature reduces Attention Deficit Disorder symptoms.
Trees increase property values: The USDA Forest Service has found that mature trees add an average of 10 percent to a property's value.
Businesses do better on tree lined streets: A 2004 study found that consumers overwhelmingly preferred business areas with well-planted canopy-covered streets and suggests a link to the amount of time that shoppers are willing to spend in stores.
Trees can reduce heating and cooling costs for buildings: When placed strategically around buildings, trees can reduce cooling costs by 30 percent, and heating costs by 20-50 percent. By providing shade and a barrier to wind, trees cool buildings during hot weather, and limit snow accumulations during cold weather. Economically this is beneficial as it can reduce the fuel costs associated with heating and cooling.
Crime rates tend to be lower in areas with trees: Research presented at the American Association for the Advancement of Science conference (AAAS) in Chicago socio-cultural benefits showed that the presence of trees could cut crime by as much as seven per cent.
Cultural Ecosystem Services is the term used for the nonmaterial benefits for people. While these can be hard to quantify, they are essential for quality of life and overall well-being.
Trees help to define a 'sense of place' and provide desirable landscapes: The aesthetic benefit of trees is obvious. Their size and color can help to soften the often-harsh urban landscape. Perhaps less obvious are the ways in which trees can contribute to the 'sense of place' or unique characteristics that define our geographic communities. Species type, placement, and even long-standing individual trees can underscore regional history, culture, and identity.
Trees and urban forests encourage community interaction: People tend to gather more when green spaces are available.
Trees help to reduce noise pollution by absorbing and blocking urban noise: This has been shown to reduce stress for people living and working around trees.
Habitats created by urban forests provide educational opportunities for people: Urban forests provide opportunities for environmental educational programs for both children and adults. Many schools have "outdoor classrooms" with curricula designed for the natural sciences.
Tree lined streets can help improve road safety
Some studies have found trees lined streets promote safer driving by giving the impression of narrowing streets. They also provide a buffer between vehicles and pedestrians.
Tree planting can be a very valuable tool for reclaiming derelict land within cities
The management of vacant property is an ongoing problem for many local governments. Even during periods of economic prosperity, when residential and commercial real estate development is high, there often remain neglected lots and other open spaces that place a high demand on code enforcement, solid waste and other municipal services. Planting trees and shrubs can offer a cost-effective way to manage such properties on either a short- or long-term basis.