This dataset comprises of the boundaries of Ancient Woodland sites in Wales. Each site is categorised as either Ancient Semi Natural Woodland (ASNW), Restored Ancient Woodland Site (RAWS), Plantation on Ancient Woodland Site (PAWS) or Ancient Woodland Site of Unknown Category (AWSU). Initially all woods greater than 2 ha shown on the Ordnance Survey (OS) 1:25 000 1st Series maps surveyed between 1880 and 1960 were considered. Evidence as to which of these were ancient was provided by presence on the earlier 19th century OS 1st Edition Maps (surveyed 1805 - 1873; scale 1:63 360). The general presumption was that woodland on 1800s maps was ancient, unless there was other evidence that the wood originated between 1600AD and 1800. Supportive indications of ancient status included the woo
d's name, its situation in the landscape, and the nature of both the surrounding pattern of enclosure and the pattern of boundaries within the wood. Where available, field survey data such as the presence of indicator species, or other historical maps and documents were also used. In mountainous areas such as Wales the first edition Ordnance Survey 1 inch maps were hard to interpret because the heavy hatching used to indicate steep slopes tended to obscure tree symbols.
The 2021 update to the ancient woodland inventory includes changes to the 2011 version resulting from the provision of additional evidence presented to NRW through public enquiries. This includes private estate maps, tithe maps, management records and photographs. The evidence has been considered by a panel of NRW experts and the inventory amended if the evidence indicates that a site has had another land use for a significant period, i.e. woodland is absent from the site in two consecutive epochs of OS historic maps, or there has been significant ground disturbance to the site, e.g. quarrying, mining or development.
Amendments include removal of sites from the inventory, adjustments to boundaries or changes to the ancient woodland category of sites.
The 2011 version remained static until it was replaced by the 2021 version
The 2021 version is being updated at least annually as new evicence becomes available.
An older 2004 version of the dataset also exists - please see metadata for dataset number NRW_DS125363 - Ancient Woodland Inventory for Wales 2004 (AWI2004) https://libcat.naturalresources.wales/folio/?oid=125363