Just so you don't worry too much.

MYTH:We're running out of trees.

FACT:We have more trees today than we had in 1970, on the first Earth Day even more than we had 70 years ago. In the middle of the last century, for example, Vermont, Massachusetts and Connecticut were about 35% forested; today they are 59%.

http://bugwood.org/intensive/myths_and_facts_about_u_s__for.html