Topping Trees is a crime against nature
An article that a large amount of so called tree surgeons, and I use the term very loosely, should read as well as those with trees. There's a huge difference between pollarding, which should be carried out when trees are immature, and topping. If your arborist/tree surgeon recommends this, and claims to work to bs3998:2010, then you really need to be looking for someone else. Not only is it contradictory to the standard it's really poor for the trees health. http://www.thedailynewsonline.com/curr/topping-trees-is-a-crime-against-nature-20151121