Table 1.

Mean reduction in wind load at three velocity levels (11, 16, and 20 m/sec [25, 35, and 45 mph]) for each pruning type or for trees with all of the foliage stripped off of the branches.

Pruning typeVelocity (m/sec)Velocity (mph)Reduction in wind loadz (N)P-value
Lion tailed1125  78< 0.01*
Lion tailed1635140< 0.01*
Lion tailed2045200< 0.01*
Reduced1125  96< 0.01*
Reduced1635130< 0.01*
Reduced2045144< 0.01*
Stripped1125136< 0.01*
Stripped1635209< 0.01*
Stripped2045270< 0.01*
Thinned1125  45< 0.01*
Thinned1635  78< 0.01*
Thinned2045103< 0.01*

  • ↵z Reduction in wind load (measured in newtons, N) is the difference between wind load before pruning and wind load after pruning.

  • ↵* Highly significant difference in wind load before and after pruning or stripping foliage.