Summary of results

Removing branches from the crown of live oak reduced trunk movement. Reduced motion likely resulted in lesser forces transferred to the trunk and roots and reduced likelihood of trunk failure in wind. This effect is likely a combination of mass damping, reduced sail area, and reconfigured crown shape. Thinning and reduction appeared most effective at reducing trunk movement in the upper crown. Lions tailing (crown raising) appears ineffective at reducing trunk movement in wind storms. Much more research is needed, including the testing of different species, different pruning doses, larger trees, gusty winds, and testing the effect of wind for longer durations. In addition, we know nothing about how long the pruning effect on movement described above will last.

Means in a column followed by the same letter indicate no difference.