Ancient woodland

‘Ancient Woodland’ is a term used in the United Kingdom to refer specifically to woodland dating back to 1600 or before in England and Wales (or 1750 in Scotland). Before this, planting of new woodland was uncommon, so a wood present in 1600 was likely to have developed naturally.

For many species of animal and plant, Ancient Woodland sites provide the sole habitat, and for many others, conditions on these sites are much more suitable than those on other sites. Ancient Woodland is the UK's equivalent of rainforest, home to more rare and threatened species than any other UK habitat. For these reasons Ancient Woodland is often described as an irreplaceable resource, or 'critical natural capital'.

Ancient Woodland is formally defined on maps by Natural England and equivalent bodies, and is given a degree of administrative protection.

The analogous American term is "old growth forest".

Characteristics

The definition of Ancient Woodland includes several sub-types. Ancient Semi-Natural Woodland (ASNW) is composed of native tree species that have not obviously been planted. Planted Ancient Woodland Sites (PAWS) (also known as Ancient Replanted Woodlands) are ancient woods in which the former tree cover has been replaced, often with non-native trees; features of Ancient Woodland often survive in many of these woods too, including characteristic wildlife, and structures of archaeological interest.

Species which are particularly characteristic of Ancient Woodland sites are called Ancient Woodland Indicator (AWI) species, an ecological indicator. The term tends to be applied more commonly to plant species than to animals, as they are slower to colonise planted woodlands, and are thus viewed as more reliable indicators of Ancient Woodland sites. Lists of Ancient Woodland Indicator species among vascular plants were developed by the Nature Conservancy Council (now Natural England) for each region of England – each list containing the hundred most reliable indicators for that region. The methodology used involved studying the flora of known woodland sites and analysing occurrence patterns to determine which species were most indicative of sites which existed before 1600. Although Ancient Woodland indicator species can and do occur in post-1600 woodlands, and also in non-woodland sites such as hedgerows, it is uncommon for a site which is not Ancient Woodland to host a double-figure AWI species total.

Ancient Woodland Inventories

Ancient Woodland sites over 20,000 square metres (5 acres) in size are recorded in Ancient Woodland Inventories, compiled in the 1980s and 1990s by the Nature Conservancy Council in England, Wales, and Scotland; and maintained by its successor organisations in those countries. There was no inventory in Northern Ireland until the Woodland Trust completed one in 2006.

Decline

Britain's Ancient Woodland cover has declined greatly. Since the 1930s almost half of ancient broadleaved woodland in England and Wales has been planted with conifers or cleared for agriculture. Only 3,090 square kilometres (760,000 acres) of ancient semi-natural woodland survive in Britain – less than 20% of the total wooded area. More than eight out of ten Ancient Woodland sites in England and Wales are less than 200,000 square metres (49 acres) in area, only 501 exceed 1 square kilometre (250 acres) and a mere fourteen are larger than 3 square kilometres (740 acres).

Management

Most Ancient Woodland in the UK has been managed in some way by humans for hundreds (in some cases possibly thousands) of years. Two traditional techniques are coppicing (harvesting wood by cutting trees back to ground level) and pollarding (harvesting wood at about human head height to prevent new shoots being eaten by grazing species such as deer). Both techniques encourage new growth while allowing the sustainable production of timber and other woodland produce. During the 20th century, use of such traditional management techniques has declined while there has been an increase in large-scale mechanised forestry. These changes in management methods resulted in changes to Ancient Woodland habitats, and a loss of Ancient Woodland to forestry.

Examples

* Coldfall Wood, London
* Edford Woods and Meadows, Somerset
* Forest of Dean West Gloucestershire
* Foxley Wood, Norfolk
* Grass Wood, Wharfedale, Yorkshire
* Hatfield Forest, Essex
* Highgate Wood, London
* Holt Heath, Dorset
* Parkhurst Forest, Isle of Wight
* Queen's Wood, London
* Vincients Wood, Wiltshire
* Wentwood, Monmouthshire
* Whinfell Forest, Cumbria
* Wormshill, Kent: Barrows Wood, Trundle Wood and High Wood
* Wyre Forest bordering Shropshire and Worcestershire