If the bark has been removed entirely around the tree, the chances of survival are next to not at all. Got any pics?
You can make or purchase some type of tree protector. Here's one type. You can also google 'tree trunk protector' and click on 'Images' to get ideas on how to make one. Just be sure there is room for air circulation and growth of the tree.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.