Can Urban Trees Fight Crime?

Trees do more than provide shade.

Is the oak tree outside your home the next Superman? New research suggests that it may be more protective than it appears. Geoffrey Donovan conducted a study in Portland, Oregon, which showed a negative correlation between tree size and crime rates. The larger the crown area of trees, the lower the crime rates.

Well-established trees may deter potential burglars by creating the impression that an area is well cared for, and subject to effective authority. Donovan’s study controlled for a number of factors, including the ethnic makeup of the neighborhoods and the value of homes. However, Donovan also admits that areas with larger trees were probably historically well maintained, which resulted in lower crime rates.

This makes sense, as there is also a strong correlation between tree cover and income level. According to a study on the demand for urban forests, for every 1 percent increase in per capita income, there was a 1.76 percent increase in demand for forest cover. When income dropped by the same amount, demand for forest cover dropped by 1.26 percent. You can see this inequality from space (or Google maps).

If the ability to fight crime doesn’t seem like enough of a reason to plant trees, don’t forget the other valuable functions of urban trees. Urban trees keep your home cool by providing shade, scrub the air of toxins (and greenhouse gases!), and decrease storm runoff.


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By Laura Hayden/image courtesy of Google Maps

Laura Hayden is an editorial intern at SIERRA Magazine. She is a rising senior at Mount Holyoke College, where she is pursuing a major in Environmental Studies, and a minor in Journalism. She has a passion for all things pertaining to growing (and eating) food, and renewable energy.

Image: Ed Coyle Photography