City dwellers can find many reasons to value neighborhood trees. The urban greenery provides relief from the built environment that many find appealing. In fact, a previous study found that a tree in front of a home increased that home's sales price by more than $7,000. Two new studies explore the measurable effects that urban trees and green spaces have a human health and crime rates.
Geoffrey Donovan, a research forester with the Pacific Northwest Research Station, used public health data, crime statistics, tax records aerial photos and other information in the two studies. He found that women who live in houses with more trees are less likely to have underweight babies. The study on crime revealed a more complex relationship. Larger trees, including trees located near the street, are associated with a lower incidence of property crimes. Larger numbers of smaller trees -- especially trees planted near the home, which may provide a screen for burglars -- are associated with higher crime.
Cities within the Portland Metropolitan Area are using this information as they rewrite street tree regulations. Likewise, local crime prevention programs and tree planting advocates are sharing the findings with urban residents.
Donovan, Geoffrey; Kirkland, John. 2011. Growing quality of life: urban trees, birth weight, and crime. Science Findings 137. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 6 p.