@Hillbillyhort and all who responded.
Thanx for the input.
I now do suspect that it was either the voles or chipmunks because I have not found any info that says that chipminks go after bark and as we all know there is plenty information that voles (mice) and rabbits do .
As to the landscape fabric, I know that it is a habitat, because during the last winter (2019) the wind got under portions of the fabric and lifted it off and there were tunnels galore under the fabric. But, there was no tree damage and I suspected that this was the work of the chipmunks. During the 2020 growing season I put out bait blocks at the above ground tunnel openings and I again suspected chipmunks as I also put the bait around the perimeter of the orchard and I had extremely minimal damage to any hanging fruit. I did NOT leave any bait out over this winter (2020)
So this Saturday I will be trying my rescue bridge grafting skills, but as a precaution, 3 weeks ago, I took muliple scion cuttings from the affected trees. I am also deep into planning for hardware cloth and othe remediation for this issue for next year.
As they say " If its not this thing then its that thing that keeps you up at night"
Once again, thanx to all who offered insight.