woodworkingboy
TreeHouser
What one article has to say about it:
Topping:
Common, but inappropriate;
Stem diameter and age not considered;
Practiced on any trees of any age;
Return pruning may not happen;
Causes decay in cut branches;
Creates weak attachments that may become dangerous;
Can decrease the tree life span.
Pollarding:
Rare, but appropriate technique;
Begins when tree is young;
Applied every one or two or three years;
All shoots are removed each time;
Shoots are only 1-inch diameter when removed;
Does not cause trunk decay;
Creates good structure;
Can have extended life span.
Topping:
Common, but inappropriate;
Stem diameter and age not considered;
Practiced on any trees of any age;
Return pruning may not happen;
Causes decay in cut branches;
Creates weak attachments that may become dangerous;
Can decrease the tree life span.
Pollarding:
Rare, but appropriate technique;
Begins when tree is young;
Applied every one or two or three years;
All shoots are removed each time;
Shoots are only 1-inch diameter when removed;
Does not cause trunk decay;
Creates good structure;
Can have extended life span.