Tree Growth after Trenching and Compensatory Crown Pruning

The roots of pin oak (Quercus palustris) trees were severed by trenching on 1, 2, or 3 sides the tree. The distance between the trunk and the trenches was approximately equal to the trunk circumference. Half of the trees also received compensatory crown pruning. All trees survived and significant dieback was noted only on trees that were trenched on 3 sides. Generally, the more extensive the trenching, the greater the growth reduction and dieback, and the longer the reduction persisted. Compensatory pruning increased twig growth for all trenching treatments, but seems to be most beneficial in reducing dieback after severe root loss from trenching. Under certain circumstances and in the absence of other construction impacts, vigorous trees may be able to tolerate and recover from trenching in the root zone.