Maple tree losing its bark
It appears the cracks in the bark have allowed the tree’s living tissue just below it to die and so the bark lets go and falls off.
The tree has been planted too deep ( there is no root collar showing as it should) and the mulch against the bark and roots keeps the bark too moist, encouraging rot. The deep planting and mulch also restrict oxygen to the roots and encourage roots to grow in a circle, which may be girdling the tree.
I would have an arborist out to examine the whole tree, especially the root zone. These professionals have taken training in care, diseases, pests and passed certification tests. He/she will come on site and give a complete diagnosis and a plant care plan, or recommend replacement if necessary. He/she can remove a girdling root where possible, expose the root collar, and suggest other things that may help. Find certified arborists by zip code here—-
What you can do-
Pull back the mulch from the trunk a few inches. Look for any sign of rot or a thick root growing tightly against the trunk. Keep the tree watered during dry times, watering from below so leaves don’t get wet. If this tree seems to be surviving despite the damage, protect the trunk in late fall and winter by wrapping the trunk loosely with a tree wrap. Remove the wrap each spring. This may help reduce cracking and sunscald.
Here are some references that describe tree care and winter protection-
See pages 11, 14 and 15 here for mulching, guards, and girdling root-
See this for protection from sunscald over winter-
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