Excessive Lifting / Thinning
Lifting trees is a common pruning practice where the lower branches of the tree are removed to provide clearance for cars, structures, etc. Over lifting, or excessive thinning of trees, is a poor pruning practice. This type of pruning causes trees to be top heavy, reduces trunk taper and increases the chances of branch breakage. It also disfigures the natural form of the tree.
Why is it bad for trees?
The center of gravity is pushed higher up into the canopy, leaving the tree vulnerable to higher wind speeds. The foliage is concentrated at the ends of branches which reduces branch taper, destroys the natural form of the tree, and it increases the likelihood of limbs breaking.
Pruning should result in the even distribution of branches throughout the entire crown, not just the top. Trees should be inspected every year. Remove dead and crossing/rubbing branches and prune to encourage good structure. Older trees that have been maintained properly do not need pruning every year.