The reduction in height and/or spread of the crown (the foliage bearing portions) of a tree. Crown reduction is primarily performed to make a tree more suited to its immediate environment, or to reduce the effects of shading and light loss, etc. The final result should retain the main framework of the crown, and also a significant proportion of the leaf bearing structure; leave a similar, although smaller outline, and not necessarily achieve symmetry for its own sake. Cuts should be as small as possible and in general not exceed 100mm diameter unless there is an over-riding need to do so. Reductions should be specified by actual measurements, where possible, and reflect the finished result, e.g. ‘crown reduce in height by 2.0m and lateral spread by 1.0m, all round (all measurements approximate.)’. Crown reduction should not be confused with ‘topping’, an indiscriminate and harmful treatment.