The Local Arborist

Root collar excavation can reveal why your tree is declining slowly.

Stem girdling roots choke off the flow of water and nutrients between the roots and branches and food produced in the leaves from reaching the roots.

They can also compress and weaken the trunk of a tree at or above the root collar flare (the junction between the trunk and the main roots) causing it to lean and lose its stability. Girdling roots may girdle other roots, but there is no known harm in this. Trees having stem girdling roots suffer a slow decline in health and a premature death.(Missouri botanical garden)