Benefits of Trees

Environmental

-Trees absorb carbon dioxide to use in their photosynthesis process. A mature tree can absorb CO2 at an incredible rate of 48 lbs/year. (1)

-Trees absorb pollution in the form of particle matter. There is up to a 60% reduction in street level particulates with trees. (2) Trees further their cleansing work by
absorbing gaseous pollutants into their leaves and trapping and filtering particulates on
and through their leaves, stems, and twigs. (3)

-Trees release oxygen into the atmosphere. Each mature tree releases enough oxygen to support two adults. (1)

-Trees can reduce cooling needs by as much as 30%.  Urban areas develop what are known as “heat islands”, where the prevalence of dark, developed surfaces such as parking lots take on very high temperatures when exposed to sun. Trees help assuage this problem by shading heat islands, as well as shading buildings from sun.  (4)

-Tree canopies, trunks, and roots all help to lesson flooding effects during a downpour by slowing the water’s descent. Research indicates that 100 mature trees intercept about 100,000 gallons of rainfall per year in their crowns, reducing runoff and providing cleaner water. (3) They also filter particulate matter that ends up in sewers and eventually streams, reducing water pollution. (5)

-Tree roots hold soil in place. Decaying leaves form an organic layer on the ground that allows water to percolate into the soil, which also reduces runoff and soil erosion. (3)


Social/Economic

-Trees can increase property values as much as 10%, according to studies done by the Realty Association of America (7)

-Trees provide many intangible benefits to a community, such as enhancing a community’s sense of self-esteem and ownership. Tree plantings project a visible sign of change and often initiate other community renewal and action programs. (3)

-Trees can even help hospital patients recover more quickly than those who have no view of greenery. (3)

-Trees reduce street noise and provide a visually-pleasing buffer from manufactured urban sites, such as road medians and concrete walls. (7)

-In a University of Illinois study, researchers Kuo and Sullivan found some amazing effects of trees on residents of public housing projects:
-In areas of more visible green space, domestic violence and child abuse decreased and social service budgets were reduced.
-Neighborly relationships were strengthened and improved in treed areas. (6)


Sources:
(1) McAliney, Mike. Arguments for Land Conservation: Documentation and Information Sources for Land Resources Protection, Trust for Public Land, Sacramento, CA, December, 1993

(2) Coder, Dr. Kim D., “Identified Benefits of Community Trees and Forests", University of Georgia, October, 1996.

(3) Southern Center for Urban Forestry Research & Information: USDA Forest Service; Athens, GA; 2004 (16).

(4) Michigan State University Extension, Urban Forestry #07269501, “Benefits of Urban Trees”

(5) American Forests Magazine, "Trees Tackle Clean Water Regulations", Summer 2000.

(6) http://www.coloradotrees.org/benefits.htm

(7) Jaluzot, A. City of Chicago Dept. of Planning and Development- Zoning and Land Use Division, October 25, 2005.