Question
I have 3 Shagbarks that are rotting at the base of the trunk - it is about 15 degrees of the circumference and does not seem to effect the strength of the tree. I have been told to cut them down and I have also been advised that they are fine and do not pose a danger and will not fall down at any moment. Ca you assist me on making a determination on what action to take if any on these trees... Thank you.

Answer
Decay fungi infect wounds on trees and over time will decay the woody part of the tree. These cells are dead and their decay causes no real health problem to the tree except for the possibility of wind breakage. A hollow pipe is about as strong as a solid bar. Over time the decay may reach into the limbs and these may break off during wind storms. Hickory is a hard wood and not easily decayed and the fungi will be slower than if the wood were softer. If the foliage is green and healthy looking I would not cut the tree. If in years ahead some of the large limbs break at the trunk then depending on the location of the Tree you might consider replacing the tree. This will either be many years down the road or not at all. Since these are hickories I see no need to remove them at this time.