Thie bark on the base of my Crab Apple has been gnawed off over the past few days. It isn't around the whole tree, just in two large areas from the base to about a foot above. There are squirrels, red squirrels, rabbits, voles, moles, mice, and deer in the area. So I'm not sure who the culprit is. I'm very upset as this is one of the trees that I replanted after the ice storm 10 years ago. As I bought a mature tree at the time that cost several hundred dollars, the tree is anywhere from 14-16 years old and would cost me a fortune to replace. I don't think the tree is killed though it is damaged. Is there anything I could do to repair the damage besides using hardware cloth to protect the tree? Also, is there any repellant I can use to keep the culprit away?