Quite a bit of bark is peeling off of my silver maple. I have several of these trees and the most bark is peeling off the largest, but the others are starting to look like the largest one did a few years back. I thought I had read some time ago, that this isn't really a problem, but it's quite extensive, so I looked it up today, and it appears that it might be a problem. However, I don't see any fungus underneath, and the peeling is not associated with a canker. Otherwise, the tree seems healthy. Any idea of what we should do?