Tree Form Classification

A tree with a good clean single trunk as typically seen in woodland and for most conifers. The girth can be recorded at the standard 1.5m above ground level. Low branches do not appear to exaggerate the girth at this point.

May be described as a maiden tree but can be a pollard or a single stem arising from a coppice or part of a multi-stem. Where low branches or bumps and burrs obstruct measurement the girth may be recorded from 1.2m – 1.7m and described as a Category A tree if the tree has a well defined single trunk up to 1.5m

Where there are champions of the same species with different tree form, generally the largest Category A tree will be considered the definitive champion although it may not be visually the most impressive!

This is a tree whose smallest girth is generally recorded between ground level and 1.2m due to low branches, bumps and burrs. It includes heavily burred trees which may still be recorded at 1.5m but where the girth is clearly exaggerated by the burrs and so not readily comparable to a similar sized Category A tree.

Many ancient oak pollards fall into this category, often being measured at 1m-1.2m. May also describe a tree arising naturally as two or more stems where it appears to have a natural low fork on a single short trunk.

Where a Category B tree is larger than the largest Category A tree, this will also be shown as a champion, alongside the largest Category A tree.

Where no Category A tree is displayed, the largest Category B tree will generally be considered. the definitive champion.

This is a tree whose girth appears to be made up of two or more stems arising close to the ground or from a short stump. May arise from the same root or independently but fused together. It includes trees described as being multi-stemmed, coppice and bundles – arising naturally, from management or deliberate plantings.

The girth will be the smallest measurement recorded between ground level and 1.5m and whilst some fused bundles can be measured at 1.5m, it will frequently be close to the ground, between 0.1m-0.5m.

Where a Category C tree is larger than the Category A and B trees, this will also be shown as a champion. Category C trees often have an impressive volume and although this is not measured, these trees are often visually more impressive than Category A or B trees.

Some tree species grow naturally as this form and where no Category A or B trees are displayed, the largest Category C tree will be considered the definitive champion, although they may not always be directly comparable.

This is a tree which is often fragmented or collapsed and the measurement obtained is not comparable with anything else. The tree may often be in its developmentally ancient phase of life and be historically of great interest.

Whilst these trees may not usually be considered ‘champions’ they are ‘otherwise remarkable’ and justify being included for reasons often given in the comments field.

A tree that was once intact and a champion in the A or B categories may, over time, become a category D.

This tree is possibly a category C but its origins are unclear and a recorder may feel that more than one tree could be involved or it appears unique in appearance.

Trees that were layed and regrown in hedgerows and on historic woodbanks may fall into this category.

Always an ‘otherwsie remarkable’ tree, usually due to its unusual form.

This tree in the datbase has not been designated a tree form but is generally assumed to be either an A or B.

Photos added later may help confirm its tree form but may not have been seen by our Registrar to update the information.

If you add photos that help confirm a tree form category, please let us know.