There is an old adage that growth follows the knife. Which in normal parlance means the tree will have developed a root system in balance with the canopy. If you suddenly chop off more than a third of the canopy the tree will try to regrow frantically to "re-balance" itself. This is particularly true if you do it in late winter early spring. If you watch last night's GW you will see Monty pruning a pear tree and talking exactly about this topic.
Posts
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.