When grading occurs, the fibrous roots of the trees are damaged by ripping or tearing. This decreases the tree's oxygen intake and changes the water table.
When grading is necessary it is recommended that the tree's roots are pruned.
Root pruning consists of using a special high velocity air tool to remove the dirt. The dirt around the tree's base and within the CRZ is airspaded. The roots are then selectively hand pruned and cut back to prevent tearing of the root systems during grading. Hand pruning will allow for clean cuts rather than tearing of the roots.
The tree preservation plan should include how grading will affect the tree and what procedures should be taken.