Known as the Elm City, New Haven is home to 32,000 street trees and parks covering 2,200 acres. Approximately 38 percent of all land is covered by tree canopy, slightly higher than the average tree canopy cover for US cities of similar size.
Results showed that for every 10 percent increase in tree canopy cover there was a 15 percent decrease in the violent crime rate and a 14 percent decrease the property crime rate. Researchers controlled for socio-economic factors, including neighborhood-level educational attainment, median household income, racial/ethnic composition, population density, vacancies and renter-occupied housing, suggesting that our results are not confounded by higher socio-economic neighborhoods having more trees. –(November 20 ) on the Alliance for Community Trees website.
AND blog post by the study authors: http://blogs.lse.ac.uk/usappblog/2015/11/20/trees-a-new-partner-in-the-fight-against-urban-crime/?utm_content=25407037&utm_medium=social&utm_source=twitter