Research published in 2002, from Dr. Frances Kuo, University of Illinois Human Health and Landscape Laboratory, revealed trees were found to be directly correlated with more sociable, less aggressive and safer communities.
Additionally, a plethora of research also indicates the important environmental role urban trees and greenspaces play. They ably reduce stormwater runoff; they clear the air of particulate matter that impairs human health; they capture carbon and cool temperatures in cities, which have remarkable local and global effects.
In 2005, Dr. Kathleen Wolf published research regarding business districts and trees, finding that trees and well-kept landscapes were much preferred over sparse landscapes by consumers. The research made a direct connection between general perceptions of retail locations; the quality of products within those places; and even the duration of consumer visits to those places.