Roger Dooley discusses in this post on the Future Lab blog that there is evidence that imagery of trees in green marketing actually has behavioral and psychological effects.

During his research Roger discovered that desk workers who did not have views of nature reported 23 percent more incidents of illness than those had had nature views outside of their desks.  In a different experiment settings of trees produced significant recovery to stress balances after only 5 minutes. Hospital patients who had views of trees also recovered more quickly than those who didn’t have any views. Most of these examples were taken from post-gazette now.

Marketers can learn a lot from this behavior as more and more companies are evolving towards green marketing and greener initiatives.