As a tree matures it is completely natural for it to produce dead and dying wood. The general process of ” dead wooding ” is to remove dead, dying and diseased branches throughout the crown.
A dead branch will at some point decay back to the parent stem causing abscission and fall off. This process can be quicker due to high winds and extremities of temperatures. Therefore the main reason dead wooding is carried out is safety. The situations that usually demand such removal would normally be trees that are in gardens, public areas or overhanging houses and public roads.
Another reason for dead wooding is amenity value, i.e. a tree with a large amount of dead wood throughout the crown looks more aesthetically pleasing with the dead wood removed. It will also help remove unwanted weight , wind resistance the tree carries and can help overall balance.