Don't get me wrong, I am not laughing with you.  
The concept is simple, Tree's grow and die.  Young trees grow best by far when exposed to lots of light and water. They don't get that when shadowed by the canopy of a degenerating forest. Wildlife flourishes in the areas exposed to sun and water. People feed their families by harvesting this otherwise wasted highly renewable resource. Trees grow back.  I could take you places that have been logged and tell you that you were standing in an old growth forest and someone like you would never know the difference.