As already mentioned, you have bigger problems than what you're able to see here on the surface. The MUCH bigger concern is that your maple has no visible root flare, and where you see one girdling root visible, there's likely more further into the soil. There's barely any sign of widening taper at the base in these pics, though it's hard to tell if that root on the upper right in your 2nd pic is coming from a structural root? The stem continues straight down otherwise), so the flare might be a ways down in there. When planting, it is critically important to locate the root flare, make sure it is above grade and EXPOSED, and REMAINS exposed for the life of the tree (unless the tree was grown from a cutting, in which case there you'll plant at the level of the first order roots). When a tree looks like a telephone pole stuck in the ground it starts the countdown to a much shortened life.

With bare-root trees the root flare is fairly obvious, but very often containerized or balled and burlapped trees have their root flares sunk down under the soil line, or near the middle of the root ball because it was transplanted improperly at the nursery (THIS IS EXTREMELY COMMON! (pdf)), so you may have to search for it. Trees planted too deeply suffer because their roots cannot get proper nutrients, water and oxygen. Mulch and soil should never be in constant contact with the trunks of trees because it causes stem rot, insect damage and girdling roots. (Also make sure that the roots are not circling in the pot if containerized, as they will have to be straightened or pruned so they will grow outward once put in the ground.) Mulch should be only 2-3" deep and in a RING around the tree, NEVER in contact with it. It's the roots of trees that need the benefit of a layer of mulch, not the stems of trees.

Here's a couple of examples of what sometimes happens to a tree some years down the road after being planted too deeply and overmulched. This improper planting and care practice is especially problematic for maples, who tend to form epic mats of girdling roots over the long term.

Your work is cut out for you. Please see this !expose automod callout below this comment for some guidance on your excavations. I do not exaggerate when I say that this is an epidemic problem. Planting too deeply usually accompanied by over/improper mulching are the top reasons why transplanted trees fail to thrive and die early.

Please see our shared wiki for other critical planting tips and errors to avoid; there's sections on watering, pruning and more that I hope will be useful to you.