In the past coppice has been an important renewable source of wood but as timber extraction has become more industrialized and competition from sources abroad has grown, coppice woodland has become less economic to manage and has been left to become derelict or has been replaced by conifer woodland. Many species that depend upon this valuable habitat have suffered as a result.
What is coppice?
Coppice is woodland where the trees are cut periodically, and are left to regrow from the cut stumps, known as stools often producing multiple stems. The word coppice is derived from the French 'couper', meaning to cut. It is a highly sustainable method of producing rapidly growing useful wood without the need to replant. Although most native hardwood trees in Britain such as oak, ash, willow and birch will coppice freely, those coppiced in the High Weald are Hornbeam, Hazel and Sweet Chestnut. Today Sweet Chestnut has largely taken over from Hornbeam as it is more economically viable as a crop because it grows more quickly and therefore can be cut more regularly ie at shorter intervals.
How does coppicing work?
Traditionally, coppice was grown as a wood containing coppiced trees (underwood) and scattered timber trees (standards). Occasionally woods consist purely of underwood and these are termed 'simple coppice'. Standard trees are usually oak but ash is also common. In an actively coppiced wood, an area of the underwood is cut each winter between October and March, before the sap starts to rise in response to the onset of spring.
Within a single wood, coppicing usually gives rise to an irregular patchwork of woodland with trees (ranging in size from a half to three hectares) at different stages of growth. The regrowth from the cut stools can be remarkably fast and it is quite normal for many species to reach two metres after their first year. The interval between cuts (the rotation length) depends on the species and the intended product. Hazel is usually cut every 7 - 10 years, sweet chestnut usually at about 15 years (except where it is cut as young as 3 years to make walking sticks) and slower-growing species such as Hornbeam are cut every 25 - 35 years.
How does wildlife respond to the coppice cycle?
Every time a coppice cycle is initiated, a sequence of changes is set in motion and develops in the following way. In the first summer after cutting, the woodland floor usually has a fairly sparse covering of vegetation, however by the second year the ground vegetation is very prominent with spring flowers and other plants. In midsummer, the woodland floor is flooded with light and this triggers a rapid change in its appearance. Seeds which have lain dormant, sometimes for many years, germinate in response to this additional light.
The coppice in the first 3 - 4 years is still very open, allowing species such as birch and bramble to establish themselves, the result is usually an almost impenetrable tangle of low foliage which will normally persist until the leaf canopy closes at around 5 - 8 years after being cut. The increase in shading at this stage rapidly eliminates the vegetation beneath the canopy and until the next cutting very few changes take place other than continued growth of the coppice stools. Under the shade of mature coppice the ground layer is normally very sparse.
Small mammals such as wood mice, shrews and bank voles are also strongly influenced by coppice cycle. Once again, when coppice has been cut there is an increase in these mammals and a third year after cutting a coppice woodland can support double the density of small mammals than at any other stage of coppice growth. Numbers then decrease, but remain fairly stable until the next cutting. Coppiced woodland in the south and west of England is one of the most important habitats of the Common Dormouse in Britain. Without a continuous coppice canopy the animal is severely restricted in its ability to move about the wood and as such as a protected species.
Coppiced woodland traditionally provided two main crops - poles cut from the underwood and timber obtained from the standard trees. The poles cut from coppice wood are used for many different purposes ranging from firewood to fence panels, depending on the species and the age at which the poles are cut. For instance seven year old hazel is ideal for hurdles while fifteen year old growth is more suitable for hedge stakes and five year old Sweet Chestnut poles are ideal for trugs but fifteen year old growth is used for fence poles.
Some of the local producers and craftsmen based in and around the High Weald still use some of the abundant Sweet Chestnut for items such as hurdles, bird boxes, fencing materials, stakes, walking sticks, trugs, rustic furniture and charcoal.
The economic value of coppice woodland is slowly increasing as more derelict coppice is brought back into rotation and worked again. There may be grants available which can help to pay towards restoring coppice woodland.