Umbrella tree as a pollard, interesting idea, hopeless common name should be umbrella shrub with tree envy
Totally agree Ekka very poor compartmentaliser from your shots its clear that no pollard head has formed, and that the subsequent cuts have not been made with no clear intention of developing a pollard head.
To be honest though its probably an acceptable way of managing what is a very untidy sprawling shrub with grossly elogated branches that break very easily.
Tree-surfer there are some truely magnificent ancient pollards in the Midlands and Northern counties in the UK, well worth a day or two driving around to visit (though perhaps not enough to make me move back there!) In strong agreement with you re the many animals and fungi that survive in the decay columns in these ancient trees and feel that often they are more important to the ecosystem as a whole than the tree is. There is some variety in form from stem pollards (which presumably is what the photo is, although the tree looks almost too old for that treatment) to branching pollards, which are what most people are familar with as the pollarded street trees in larger European and American towns and cities. As you alluded to it is the maintenance of the pollarding cycle that is critical to the longevity of the tree.
Sean