I speak for the trees for the trees have no tongues

- The Lorax, Dr Seuss

Have you ever looked at trees and thought they just stand there and do nothing? It may seem that way, but in fact they are very busy doing a mixture of jobs that are really important.

What they are doing can be described as ecosystem services. Animal houses, air, rain and shade makers (If trees didn't breathe, neither could we. The health of our air, soil and water all relies on trees to keep it clean.) and even dead trees play an important role. Fallen trees provide shelter and food for many animals. See  

http://www.acfonline.org.au/articles/news.asp?news_id=3459 to read more