Question
I have two quaken aspens in my yard. I have
mushrooms growing all around one of them. The
other has none. The mushrooms or probably toadstools, seem to be growing out of the roots
of the tree. Have you ever heard of this, and if
you have, is there anything to do for it ?
Is it too much water. This is in the front yard
and I have a sprinkler system.
Thank you for your time.  

Answer
Sounds like what we call fairy rings. Old folk lore that fairies danced there during the night. These are really just the fruiting bodies (mushrooms) of a decay fungi probally decaying the thatch of the grass. it is a common sight where a sprinker system is used allowing the fungus plenty of moisture to produce the fruiting bodies, I have the same thing from time to time in my lawn sometines near trees or out in the lawn itself. I do not think it is a problem unless the foliage of the trees are not green and healthy (soon the leaves will be changing so the leaves may not be too green)