Thank you for contacting Ask Extension. It appears that the damage is only about a foot from the ground. Not sure it is only deer causing the problem, it might also be rabbits and voles. Deer damage usually is about 1-2 feet from the ground. With what I can see, the recommendation would be to use a tree guard around the trunk or place some stakes around the entire tree and use chicken wire to encase it. That way the rabbits and deer cannot get into the tree. You can use a deterrent, but if you do, you need to verify the animal doing the damage to get the correct deterrent. It would be beneficial to move the mulch back from the trunks. Voles and rabbits do like to hide in mulch that is up to the trunk of a tree and eat away, and not be disturbed. We recommend placing mulch about 3 inches away from the trunk.

Because the damage appears to be minimal, the tree should repair itself over the course of the year and survive.

I have included some publications for your reference:

Gardeners frustrated with heavy deer damage this season - MSU Extension

Deer damage to woody ornamentals - MSU Extension

Winter deer damage heavy? Seek deer-resistant plants - MSU Extension

How to Protect Trees and Shrubs from Animal Damage Over Winter | Horticulture and Home Pest News (iastate.edu)

Effective Methods for Preventing Deer Browse Damage on Newly Planted Trees and Shubs (usda.gov)

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