By Dogtown Commoner | Posted at 8:31 pm, August 25th, 2007 | Topic: environment, cities, oakland, science
Frances E. Kuo at the University of Illinois at Urbana-Champaign has done some remarkable studies on the social benefits of trees in urban settings. In a Chicago housing project, she and her colleagues compiled interviews and statistics on buildings surrounded by trees compared with nearly identical buildings in the same housing project that did not have any trees nearby. Among the findings are the following:
Trees reduce crime:
In fact, compared with buildings that had little or no vegetation, buildings with high levels of greenery had 48 percent fewer property crimes and 56 percent fewer violent crimes. Even modest amounts of greenery were associated with lower crime rates. The greener the surroundings, the fewer the number of crimes that occurred.
Trees build community:
residents of buildings with more trees and grass reported that they knew their neighbors better, socialized with them more often, had stronger feelings of community, and felt safer and better adjusted than did residents of more barren, but otherwise identical, buildings.
Most people intuitively sense that trees are an asset to a neighborhood, but I never would have expected the benefits to be so quantifiable and dramatic. The findings aren’t lost on everyone, however — the Alliance for Community Trees is a nationwide umbrella organization for groups like Urban Releaf, which was set up in 1998 to plant trees in barren neighborhoods of Oakland and Richmond. The urban agriculture movement, which is quite large and still growing in Oakland and surrounding areas, focuses mostly on food, but it dovetails nicely with the tree-planting projects. In a 2003 paper, Kuo emphasizes the parallels between natural ecosystems and what she calls the “social ecosystem”:
In urban communities, arboriculture clearly contributes to the health of the biological ecosystem; does it contribute to the health of the social ecosystem as well? Evidence from studies in inner-city Chicago suggests so. In a series of studies involving over 1,300 person–space observations, 400 interviews, housing authority records, and 2 years of police crime reports, tree and grass cover were systematically linked to a wide range of social ecosystem indicators. These indicators included stronger ties among neighbors, greater sense of safety and adjustment, more supervision of children in outdoor spaces, healthier patterns of children’s play, more use of neighborhood common spaces, fewer incivilities, fewer property crimes, and fewer violent crimes. The link between arboriculture and a healthier social ecosystem turns out to be surprisingly simple to explain. In residential areas, barren, treeless spaces often become “no man’s lands,” which discourage resident interaction and invite crime. The presence of trees and well-maintained grass can transform these no man’s lands into pleasant, welcoming, well-used spaces. Vital, well-used neighborhood common spaces serve to both strengthen ties among residents and deter crime, thereby creating healthier, safer neighborhoods.
(Photo above was taken in 1884 by Moses Chase, and shows an oak tree at 5th and Clay Sts. in Oakland, CA. More information on the photograph can be found here)