These two terms are in common use, but they have specific meanings when it comes to their conservation. All ancient trees are veterans, but a tree may qualify as a veteran without being ancient. Most British trees increase in girth over their lifetimes by 2.5 cm a year. They grow faster when young, when in the open as opposed to woodland, and when in good soil rather than bad. They grow slower as they get older. Some species grow faster than average, such as Black Poplar, Plane, and Wellingtonia, and some more slowly, especially Limes and Hawthorns.
Trees are very good at vegetative reproduction, so that they are effectively eternal. Some create their own clumps, each tree being a clone. They do this by branches that arch down to the ground, root, and send up new vertical trees. The Tortworth Chestnut, which was regarded as ancient in King Johns reign, is a good example, but some of the limes on the Downs are doing this. Some trees send up new shoots from the base of the trunk which eventually replace the original tree. Many trees if cut to the ground, by storm or men, will promptly create new shoots, and this is the basis of coppicing which was a standard woodland management tool from at least Roman times. There is a Small-leaved Lime at Westonbirt Arboretum that now consists of a ring of clones about forty metres in diameter.
Ancient trees should be at least two hundred years old, and hence have a girth of more than five metres. I have measured 120 trees in Bristol with this girth, and there are many more in Ashton Court that I have not checked. They matter because they provide a range of habitats to a range of species. They are always hollow, often squat, having long since lost their upper branches, their hearts eaten out by fungi and beetles, full of nooks and crannies, and often clothed in lichens and ferns. They are most frequently Oaks, Sweet Chestnuts, Planes and Cedars.
Veteran trees are defined by their individuality. They will be mature, around 140/150 years old, about three metres in girth, mostly still standing tall. Fine, significant specimens of their species both in form and biodiversity. They are candidates to become Ancient, they may be starting to go hollow, and hence be of concern. They may need management to avoid their becoming top heavy, or developing a dangerous lean. They will stand out from other trees in their particular locality and may have planning protection as a consequence. They may also have special features of note, such as being multi-trunked.
Trees and Planning
The National Policy Planning Framework document (issued in July 2018) has the following definitions at Appendix 2: Glossary.
Ancient or veteran tree: A tree which, because of its age, size and condition, is of exceptional biodiversity, cultural or heritage value. All ancient trees are veteran trees. Not all veteran trees are old enough to be ancient, but are old relative to other trees of the same species. Very few trees of any species reach the ancient life-stage.
Ancient Woodland. An area of woodland that has been wooded continuously since at least 1600 AD. It includes ancient semi-natural woodland and plantations on ancient woodland sites.
Irreplaceable habitat: Habitats which would be technically very difficult (or take a very significant time) to restore, recreate or replace once destroyed, taking into account their
age, uniqueness, species diversity or rarity. They include…ancient woodland and ancient and veteran trees….
Paragraph 175 (at page 51) of the framework states:
When determining planning applications, local planning authorities should apply the following principles:
c) development resulting in the loss or deterioration of irreplaceable habitats (such as ancient woodland and ancient or veteran trees) should be refused, unless there are wholly exceptional reasons and a suitable compensation strategy exists;
Paragraph 2.17.6 of DM17: Development Involving Existing Green Infrastructure – part of the Bristol Local Plan echoes this:
Due to their characteristics and value, Aged and Veteran trees are considered to be of relatively greater importance than other trees and even trees of a similar species. Aged trees, by definition, have developed characteristics associated with great age and often have particular landscape and townscape value. Veteran trees are considered to have particularly important nature conservation value. Both will often have significant visual amenity, and potentially historic and cultural importance. As such their loss or harm will not be permitted, and the design and layout of development will be expected to integrate them into development.
These guidelines apply whether the tree or woodland grows in a public or a private place.
R L Bland