Ancient trees exist in many forms and sizes, with ages ranging according to species and environment, with some lasting for hundreds of years; smaller trees, such as in orchards, can exhibit veteran characteristics after only a few decades. A girth of more than 3 meters at 1.5 meters could be used as a measure to identify if a tree is a veteran. However, other veteran tree characteristics may be taken into account, and alternative girths may be established for different tree species. Ancient trees often have features of particularly high nature conservation value, such as dead limbs, hollows, rot holes, water pools, seepages,
woodpecker holes, splits, loose bark, limbs reaching the ground, and
epiphytic plants and
lichens. Few of these features are found on younger trees, and they provide
habitats and foraging grounds for many species of animals and fungi, some of which are rare. Such features are sometimes removed or damaged by pruning or other
arboricultural practices. Ancient trees can be found in various locations, from dense woodlands to
hedgerows, village greens, and ancient parks and wood pastures. They thrive in a variety of settings, such as dense
woodland, but are more commonly found as
hedgerow trees, on
village greens, and in ancient
parks and other
wood pastures. Many of the oldest trees are
pollards, which is a method of heavily pruning trees by cutting the tree above the browse height of animals. This cultural practice has mostly died out in the UK, except for street trees. ==United Kingdom==