Hi Steve,

The bark on young maples is soft and this happens quite often. As long as the damage doesn’t go all the way around the trunk, the tree should heal itself.

Of more concern is that the tree looks like a telephone pole going into the ground. Planting too deep is one of the top killers of maple trees because it lead to girdling roots. The tree essentially strangles itself. You should see a root flare at ground level, where the trunk widens as roots reach out.

The tree is too big to be replanted, but you can take a trowel and gently scrape mulch and soil away from the bottom of the trunk until you see the trunk widen or until you begin to hit roots coming off the trunk. 

This news story has photos that show what I mean: 

https://www.starnewsonline.com/story/lifestyle/features/2022/07/22/dont-cover-root-flare-can-harm-tree/<personal data hidden>/

If you’re nervous about doing this, consult a certified arborist for advice. You can find one here:

https://www.isa-arbor.com/

After you correct this root issue, make sure mulch doesn’t smother those roots or touch the trunk. That can lead to rot issues.

Hope this helps.