Below are some of the main aspects of tree surgery explained.
Crown lifting involves the removal of the lower branches to a given height. The height is achieved by the removal of whole branches or removing the parts of branches which extend below the desired height. The branches are normally not lifted to more than one third of the tree's total height.
Reducing the height and or spread of a tree by selectively cutting back to smaller branches and in fruit trees for increasing of light interception and enhancing fruit quality.
Crown and canopy thinning increases light and reduces wind resistance by selective removal of branches throughout the canopy of the tree. This is a common practice which improves the tree's strength against adverse weather conditions as the wind can pass through the tree resulting in less "load" being placed on the tree. The shape is vital for the survival of the tree and lopping off the wrong sections of a tree if it has surpassed its height limit can actually be extremely damaging. This can hinder its growth or cause an overbalance.
Branches die off for a number of reasons including light deficiency, pest and disease damage, and root structure damage. A dead branch will at some point decay back to the parent stem and fall off. This is normally a slow process but can be quickened by high winds or extreme temperature. The main reason deadwooding is performed is safety.
A regular form of pruning where certain deciduous species are pruned back to pollard heads every year in the dormant period. This practice is usually commenced on juvenile trees so they can adapt to the harshness of the practice.