Root Crown Excavation
problem can be caused by planting a tree too deeply or by adding fill soil over the natural grade and root flares at the base of the trunk. Adding fill soil over the tree roots within the dripline is often detrimental to tree health. But fill soil added to the base of a tree is especially damaging over the long term. The fill soil over the root flares can cause the bark and cambium layer in the trunk and root flares to decay. The trunk cannot tolerate constantly moist soil like root tissue can. No root flares are evident in the photo above indicating fill soil has been added. In the photo fill soil along with the restricted root space and the very probable construction damage do not provide a good prognosis for the long term survival of the tree.
Another problem caused by fill soil over the root flare is the formation of stem girdling roots that can cut off circulation in the root flares and portions of the trunk.