The crown of the tree is the foliage bearing portion of the tree formed by its branches and not including any clear stem/trunk

Crown thinning – the removal of a portion of smaller/tertiary branches, usually at the outer crown, to produce a uniform density of foliage around an evenly spaced branch structure.  Normally confined to broad-leaved species. Crown thinning doesn’t alter the overall size or shape of the tree but allows more light to pass through it and reduces wind resistance and weight.

Crown lift or crown raising – the removal of the lowest branches and/or preparing of lower branches for future removal.  Again an effective method of increasing light transmission to areas closer to the tree

Crown reduction – the reduction in height and/or spread of the crown. making the tree more suited to its immediate environment.

Coppicing – the cutting down of a tree within 300mm (12 in) of the ground at regular intervals, traditionally applied to certain species such as Hazel and Sweet Chestnuts to provide stakes etc

Deadwood - non-living branches or stems due to natural ageing or external influences. Deadwood provides essential habitats and its management should aim to leave as much as possible.

Decline – when a tree exhibits signs of a lack of vitality, such as reduced leaf size, colour or density.

Dieback – where tips of branches exhibit no signs of life due to age or external influences.

Dismantling – The process of removing a tree in full or part, within a confined space with control over the timber and branches removed by methods of rigging.

Felling/Removal – The act of cutting a tree at ground level for its removal, where space and conditions allow.

Formative pruning – minor pruning during the early years of a tree’s growth to establish the desired form and/or to correct defects or weaknesses that may affect structure in later life

Lopping and Topping – terminology still included in planning legislation but generally regarded as outdated.  

Pollarding – The process of reducing a tree to back to usually a single stem for it to reshoot and produce new growth ,commonly seen in willow, poplar, limes; not all species will pollard.

Pruning – more a gardening term nowadays replaced by crown thinning, crown reduction, crown lifting above.

Tree Stump Grinding and removal - The final and often forgotten-about step in removing a tree -  the grinding of stumps to below ground level.