Wildflower is published quarterly by the Wildflower Center. Its content is national in scope with articles about the conservation and use of native plants as well as news from the Wildflower Center. A subscription is provided to Wildflower Center members as a benefit of membership.
Wildflower has long advocated planting trees for the ecological benefits they provide, like helping improve air quality as well as conserving water and energy. Now it turns out that urban trees may even help fight crime.
Researchers with the U.S. Forest Service's Pacific Northwest and Southern Research Stations have published a new study suggesting that certain types of city trees may help to lower rates of property crime and violent crime.
A sample of 2,813 Portland single-family homes experiencing 394 property and 37 violent crimes between 2005 and 2007 were evaluated to explore the relationships among crime and more than two dozen variables, including the number and size of trees on a lot and the size of trees on surrounding areas. Canopy size of both street and yard trees and the number of trees growing on a lot were found to have the most effect on crime occurrence; large trees were associated with a reduction in crime, while numerous small trees were associated with an increase.
"We believe that large street trees can reduce crime by signaling to a potential criminal that a neighborhood is better cared for and, therefore, a criminal is more likely to be caught," says Geoffrey Donovan, research forester with the PNW Research Station who led the study. "Large yard trees also were associated with lower crime rates, most likely because they are less view-obstructing than smaller trees."
The latter actually were found to possibly increase crime by blocking views and providing cover for criminals – an effect that homeowners can mitigate by keeping smaller trees pruned and carefully choosing the location of new trees.
In the fall issue of Wildflower, we looked at some of America's most loved trees and the factors like disease that threaten to destroy them. In this issue of Wildflower, we encourage you to take advantage of winter rains and milder temperatures and plant a tree this season. (See "Tree's Company" on page 28 and a preview for the Center's annual Tree Talk, Winter Walk event on page 7.) You might sleep more soundly if you do.
— Christina K. Procopiou