Large trees discourage criminals

WASHINGTON - Large trees seem to discourage crimes while small trees have an opposite effect, says a new study.

“We believe that large street trees can reduce crime by signalling to a potential criminal that a neighbourhood is better cared for and, therefore, a criminal is more likely to be caught,” said Geoffrey Donovan, research forester with the US Forest Service’s Pacific Northwest Research Station, reports the journal Environment and Behaviour.

Geoffrey Donovan, who led the study, added: “Large yard trees also were associated with lower crime rates, most likely because they are less view-obstructing than smaller trees.”

Conversely, their analysis suggested that small yard trees might actually increase crime by blocking views and providing cover for criminals — an effect that homeowners can mitigate by keeping trees pruned and carefully choosing the location of new trees, according to a Northwest Research Station statement.

Their study, based on a survey of 2,813 single family homes, is the first to examine the effects of trees and other factors on crime occurrence in Portland, US.

Donovan and his colleague Jeffrey Prestemon, with the Southern Research Station, US, obtained crime data from the Portland Police Bureau from 2005 to 2007 and grouped the incidents into seven categories.