involves the reduction of the height and spread of the tree proportionally, while retaining the crown structure, effectively making the crown smaller. This can be used to:
- manage a tree growing in a limited physical space, reduce wind loading on a tree where biomechanical integrity is a concern
- help manage the water uptake of a tree (when repeated on a regular cycle)
- rejuvenate older trees (retrenchment pruning/reduction) by developing a smaller crown
It should be noted that not all tree species are suited to crown reduction works, and the physiological condition of an individual tree is also essential to consider before undertaking crown reduction work. Crown reduction is very often a cyclical operation as healthy trees will react by producing reaction growth to replace the lost branches. Cyclical reduction involves repeated removal of regrowth, back to the original reduction point, and timing of these operations will vary between tree species and locations. Reshaping the crown may involve the reduction in length of certain branches or sections of the crown only, e.g. to cut back from a building or structure, or to suit a particular location or tree.