It looks like something is eating it..
savanna is right! looks like a groundhog for sure..they do it to all my smaller tree trunks...ive shot about 5 with my crossbow just this year, scott can borro if hed like lol
Somebody is nibbling your tree. You can buy tree tape and you might have to put up chicken wire around it.
Thanks for all of your help. I have a plan of action! I just hope it's not too late for the poor little tree.