Can trees fight crime in Portland? A new study from the Pacific Northwest Research Station in the US Forest Service shows some might. But before you get out your seeds and watering can, make sure you know what kind of trees to plant.
The study, the first of its kind in Oregon, found that large trees on a front lawn were associated with an decrease in both property and violent crimes, while numerous small trees were linked to an increase in property crime.
Researcher Geoffrey Donovan says large trees may indicate to criminals that an area is well cared for, while several small trees might serve as cover for thieves.
Here’s how the Forest Service says Donovan and his colleague Jeffrey Prestemon reached their conclusions:
They got crime data from the Portland Police Bureau from 2005 to 2007 and grouped the incidents into seven categories. They examined only crimes that included a physical address and matched that information with data from aerial photographs, onsite visits, and the Multnomah County Tax Assessors Office. Their sample of 2,813 single-family homes experienced 394 property and 37 violent crimes.The researchers then conducted statistical analyses of the relationships among crime and more than two dozen variables they compiled, including the number and size of trees on a lot and the size of trees on surrounding areas.