Researchers at University of Wisconsin-Madison  state "Those places with more trees tended to be happier, and the association was "significant and sizable." The full report can be seen at 
http://www.fastcoexist.com/3029115/if-you-live-near-a-park-youre-more-likely-to-be-happy?utm_content=buffer6332f&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

Alex Pearl