Normally, trees don't like having their trunks covered by soil but perhaps there is another way to overcome this. I bow to my more experienced GOY'ers. Tugbrethil has great knowledge of trees.

It's a straight no I'm afraid - nothing should be higher around the trunk of your plant than it is already, regardless whether its woodchips or soil. Probably best to remove it and replant elsewhere if possible.

There is no good way around it that I know about. At minimum, it would require a clear well around the trunk at least out to 2/3 of the way to the drip line--and that would create other problems, especially in a humid climate. In the long run, the best choice would be to transplant the tree.

7 feet isn't that big of a tree to move. The tree won't survive if you bury the trunk. The 18 inches of buried trunk will rot & decay,killing the whole tree. Also, surrounding the tree with woodchips was really bad advice. I don't recommend it at all. The decomposing woodchips will rob the tree of valuable nitrogen & will leave an air pocket below grade, causing more problems. If you want to keep this tree, you'll have to re-plant it. Do it once, do it right and never deal with it again.

Thanks for your helpful replies - I will have the tree removed and replanted, preserving as much as possible of the root ball. It is worth it for a nice tree.

It will have an extensive root system which may go down into the soil some distance after five years; it would be better to try to move it when its dormant in winter, but if you have to do it now, be prepared for the possibility it may not survive the move. You will need to reduce the topgrowth by half if you do it now, to give the disrupted roots less work to do trying to support leaves and branches, and keep it well watered after replanting.