Coppicing and pollarding
When visiting a wood you should look for signs, particularly in the shape of the trees, that tell of the history of the wood and what it has been used for.
Trees with multiple stems are a sign of the commonest management practice, ‘coppicing’. This uses the fact, well known to all gardeners, that most broadleaved trees are not killed by being felled: the stump sends up shoots and becomes a ‘stool’ from which an indefinite succession of crops of poles can be cut at intervals of years. Aspen, cherry and most elms do not coppice; instead they send up shoots called ‘suckers’ from the root system.
Woods traditionally yield two products, timber and wood. ‘Timber’ is the large material suitable for planks, beams and gateposts; ‘wood’ is the smaller material suitable for light construction or firewood. A typical wood consists mainly of ‘underwood’ stools, felled every five to 25 years and allowed to grow again; among these stools is a scattering of ‘standard’ trees, grown to timber size. The standard trees are nearly always oak or ash. Chosen for this purpose because of their value as timber. The underwood may also be oak or ash but is often of a wide range of other trees. A ‘coppice’ is a wood managed in this way; but the term is also applied by modern writers to the underwood itself, whether standing or felled.
A year or two after a coppice has been cut the ground vegetation flourishes and encourages a rich diversity of insects. Later on, the underwood forms a dense thicket which casts an intense shade and the vegetation declines; at this stage, however, the thicket provides cover for nesting birds such as the whitethroat and blackcap.
An alternative to coppicing is ‘pollarding’. The trees are cut like coppice stools to produce successive crops of wood, but at a height of 2-4.5m (6-15ft) above ground so that grazing animals cannot reach the young shoots. Pollarding is practised on wood-pasture and hedgerow trees rather than those in woods.
In theory a coppice of 100 acres might contain 50,000 underwood stools and 2000 standard trees. Every year, the underwood on 10 acres would be felled, together with 20 of the 200 limber trees on those 10 acres. To replace the timber trees, 50 self-sown saplings or coppice poles of oak or ash would be left standing, in the expectation that 20 would eventually survive to reach timber size. In this way the whole wood would be felled on a ‘coppice cycle’ often years and would continue to yield the same produce forever. This is an illustration of what is rarely so simple or so regular in practice. Woods can vary in any proportion from all standard trees and no underwood to all underwood and no timber.
The character and continuity of a wood are maintained by the coppice stools, which (like pollards) live indefinitely. Timber trees come and go at the whims of owners, but the underwood remains.
In the past wood was usually more highly-regarded than timber and it may yet be so again in the future; but over the last 150 years — a period of cheap fuel — such woodmanship as there has been tended towards timber rather than underwood production. Most woods, where they still exist, have been left standing for between 40 and 150 years, a much longer interval than would normally elapse between fellings.