While this is a common recommendation, research has not supported it. Following root loss, unpruned trees seem to respond better than pruned trees. Obviously, any removal of branches will reduce the capacity of the tree to produce food in the leaves. Although the tree will probably lose some branches as a result of the root damage (if the tree survives the trauma), it is best to let the tree decide which ones. Thus, pruning should be limited to hazard reduction at first. Later, after the tree has responded to the damage, further pruning would be in order.
