Pollarding
From Wikipedia, the free encyclopedia
Pollarding is a woodland management method of encouraging lateral branches by cutting off a tree stem or minor branches two metres or so above ground level. The tree is given a year to regrow, after the initially cutting, but once begun, pollarding require annual maintenance by pruning. This will eventually result in a somewhat expanded (or swollen) nodes topping the tree trunk with multiple new side and top shoots growing from it.
A tree that has been pollarded is known as a pollard. A tree which has not been pollarded is called a maiden or maiden tree; which also refers to the fact that pollarding is normally first undertaken when the tree is quite young. Pollarding older trees usually result in the death of the tree. Pollarding is sometimes abused in attempts to curb the growth of older or taller trees. However, when performed properly it is useful in the practice of arboriculture for tree management.
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[edit] Practice
As in coppicing, the tradition of pollarding is to encourage the tree to produce new growth on an annual basis in order to maintain a supply of new wood for various purposes, particularly firewood.
Pollarding was preferred over coppicing in wood-pastures and grazing areas where growth from the ground upwards was less practicable, since grazing animals would browse the regrowth.
An incidental effect of pollarding is the encouragement of underbrush growth due to increased levels of light reaching the woodland floor. This can increase species diversity. However, in woodland where pollarding was once common but has now ceased, the opposite effect occurs as the side and top shoots develop into trunk-sized branches. An example of this occurs in Epping Forest in London/Essex, UK, the majority of which was pollarded until the late 19th century. Here, light levels on the woodland floor are extremely low due to the thick growth of the pollarded trees.
[edit] Species
Good examples of trees which are regularly pollarded are willows in areas surrounding meadows. The technique is also used in Africa for Moringa trees, to bring the nutritious leaves into easier reach for harvesting. Pollarding is also used in urban forestry in certain areas for reasons such as tree size management, safety and health concerns. It removes rotting or plagued branches for the overall health of the tree, living and dead branches that could harm property and people, as well as expanded foliage in spring for aesthetic, shade and pollution concerns.
Oak trees, when very old, can form new trunks from the growth of pollard branches - i.e. surviving branches which have split away from the main branch naturally.
