Question
I've just had some yard work done, and the contractor piled up earth against the trunks of two maples, about a foot high or less on one side.  He said it wouldn't hurt the trees. They are growing out of an old stone wall.  They are big and old; one is partially rotted, but looks strong and healthy enough to last a while.  Will the earth harm the trees?  I can send a digital picture.

Answer
I would disagree--the soil that was added around the tree will cause much damage to the trees root system. You can get by with adding sand but not more than 3 inches and never within a foot of the trunk.  Removing soil from around a tree will also damage the root system. I would have the soil removed back to the ordinal ground level as soon as possible.

Conspicuous symptoms of construction damage may take years to appear. Tree decline from soil compaction, for instance, may take three to seven years to appear as obvious symptoms of distress. Because of this delay, landowners often attribute tree losses to other causes. Carefully monitor affected plants and keep written records to help you recognize the less visible signs of tree stress. Remember, the most serious damage remains hidden in the root system