Nature Conservancy Council and English Nature: Ancient Woodland Inventory Dataset
Nature Conservancy Council and English Nature: Ancient Woodland Inventory Dataset
The Ancient Woodland Inventory (AWI) is an electronic dataset which identifies and records information about ancient woodland in England. For the purposes of the Inventory, 'ancient' woods are those which are believed to have been in existence since at least 1600 AD and which have only been cleared for underwood or timber production. The Inventory covers woodland sites which had an area of at least two hectares on the Ordnance Survey's First Series 1:25,000 maps. Smaller woods are excluded. It includes ancient semi-natural woodland, ancient replanted woodland and ancient woodland sites which have been cleared since the surveying for the Ordnance Survey First Series 1:25,000 maps.
The AWI covers the following types of woodland:
A single woodland site in the AWI may comprise one or more of the above types.
Three main products have resulted from the Inventory and have been used to disseminate AWI data:
Three tables (AWISITE, AWITNR and AWISTRV) record information about woodland sites, while four other tables act as lookup tables for fields in AWISITE, AWITNR and AWISTRV. AWISITE contains the main data on woodland sites and provides the following information on individual sites:
Digital boundary data relating to the AWI has not yet been transferred.
The datasets in this series are available to download. Links to individual datasets can be found at piece level.
Hardware: Before 1991, AWI data was held by the Nature Conservancy Council on a PR1ME '2255 minicomputer'. At time of transfer in 2001-2002, the database was probably available via networked PCs linked to a server.
Application software: Before 1991 the data was held in a PR1ME Information, PR1ME's database management system. By 1995 the AWI database was part of English Nature's CORDATA information system. The data was held in an Informix UniVerse database with a 'front end' provided by Informix SystemBuilder+. When the AWI was moved from CORDATA to a new information system (ENSIS) in 1995-1996, UniVerse was replaced by Oracle and SystemBuilder+ by Compuware's UNIFACE.
Logical structure and schema: At time of transfer in 2001-2002, the AWI database was held by English Nature in an information system known as ENSIS (English Nature Sites Information System). ENSIS was itself part of a wider system, TENIS (The English Nature Information System). The AWI database was integrated into ENSIS in 1995-1996 as part of the replacement of an earlier information system, CORDATA, of which the AWI database had been a component. CORDATA in turn had replaced a previous system, COREDATA.
The dataset consists of seven tables, four of which are lookup tables linked in 1:many relationships to the main AWISITE table. AWISITE is linked in a 1:many relationship to AWISTRV (ancient woodland revisions), and in a 1:many relationship to AWITNR. Of the lookup tables, SITE was only supplied in part, while NDAD did not receive the CUSTMR table which in ENSIS acted as a lookup table for the CUSTMR_ID field in AWITNR.
How data was originally captured and validated: The AWI was preceded by trials in Norfolk, Lincolnshire and Nottinghamshire. These indicated that it was feasible to identify ancient woodland sites using information from maps and existing survey data, rather than by carrying out field surveys.
The initial stage of the data gathering process involved identifying woods over two hectares on Ordnance Survey First Series 1:25,000 maps, surveyed between 1880 and 1960. These provided a 'base line' for the Inventory, and were used because they excluded afforestation which had occurred since 1945. Other sources used in conjunction with the First Series maps include:
The areas of ancient semi-natural, ancient replanted and ancient cleared woodland were measured on projections of the First Series maps using a romer dot grid overlay. For each woodland considered by the AWI, a data sheet was prepared summarising the information which had been used to determine whether the wood should be included in the Inventory. Data was input to the AWI database for those sites which had been identified as ancient.
Since the publication of the original provisional county inventories, the AWI database has been updated on the basis of more recent surveys conducted by English Nature, local authorities and wildlife trusts, and as a result of comments from the Forestry Commission and woodland owners. Revisions were also made as a result of the project to digitise ancient woodland boundaries, which led to more accurate measurements of the extent of woodland sites. Amendments to the data have included: updating data on a site's conservation status; changes to the site's ownership information; reclassification of a site from ancient semi-natural to ancient replanted woodland (and vice versa); changes to the extent of a site; the deletion of sites or parts of sites previously considered to be ancient; and the addition of sites to the AWI based on new information.
Digital boundary data: By 1994 English Nature had digitised the boundaries of ancient woodland sites in Nottinghamshire and Cumbria, while the Forestry Commission had digitised sites in North Yorkshire. In 1995 a joint project was initiated between English Nature and the Forestry Authority (then part of the Forestry Commission) to digitise the remaining boundaries of ancient woodland in England as part of the Forestry Commission's National Inventory of Woodland and Trees. The digitisation was carried out by the Forestry Authority at 1:25,000 scale using the 1:50,000 maps in the provisional county inventory reports. For some counties 1:25,000 maps were used where available.
The digitisation project is thought to have been completed in 1999. When the first AWI dataset was transferred in 2001-2002, AWI digital boundaries and associated data from the AWI database could be downloaded from English Nature's web site as 26 separate files based on Ordnance Survey grid letters. Each file could be split into up to four sub-files based on 50 km x 50 km Ordnance Survey 'tiles' or quadrants.
Constraints on the reliability of the data: The general limitations of the AWI are discussed in the report by Spencer and Kirby, 'An Inventory of Ancient Woodland for England and Wales' (found in the dataset documentation catalogue). The limitations of the digital boundary data are discussed in English Nature Research Report 313. In particular, it should be noted that the AWI's approach has been to include rather than exclude borderline sites. Sites have been retained in the Inventory even if there is uncertainty over whether they should be classed as ancient, on the grounds that this will allow their status to be re-appraised when more information becomes available.
A dataset relating to the National Inventory of Woodland and Trees can be found in: F 45
|Held by:||The National Archives, Kew|
|Former reference in The National Archives||CRDA/43|
|Legal status:||Public Record|
English Nature, 1991-2006
Nature Conservancy Council, 1973-1991
|Physical description:||2 datasets and documentation|
|Restriction on use:||The copyright of the AWI dataset and dataset documentation belongs to English Nature. Copies may be made for private study and research purposes only.|
|Immediate source of acquisition:||In 2010 the United Kingdom National Digital Archive of Datasets|
|Custodial history:||Originally transferred from English Nature in 2001. The United Kingdom National Digital Archive of Datasets (NDAD) then held the dataset until 2010 when it was transferred to The National Archives (TNA).|
|Selection and destruction information:||AWI data and related documentation was selected for preservation under section 126.96.36.199 of the PRO's Acquisition Policy, the impact of the state on the physical environment.|
|Accruals:||It is anticipated that further accruals will occur.|
|Publication note:||A number of publications relating to the AWI have been produced by the Nature Conservancy Council and English Nature, including: provisional county inventories, consisting of a report and an accompanying printout of data for each county; English Nature Research Reports listing amendments to the AWI since the publication of the provisional county inventories and any previous updates and English Nature Research Reports which provide general information about the AWI.|
|Unpublished finding aids:||Extent of documentation: 114 documents, Dates of creation of documentation: c.1995-c.1996|
|Administrative / biographical background:||
The Ancient Woodland Inventory (AWI) grew out of recognition in forestry circles, by the late 1970s, of the importance of ancient woodland in nature conservation. Studies by George Peterken and Oliver Rackham emphasised the distinctive nature of woods which had existed since medieval times, as opposed to woods which had been planted or grown up naturally in the last few centuries. Ancient woodland sites often contain communities of animals and plants which are confined to, and dependent for their existence upon, ancient semi-natural woodland. Many natural characteristics of such sites, such as woodland composition and soil profile, are important to nature conservation and may be relics of the original natural forest cover. Ancient woodland can also contain historical landscape and archaeological features which are important in their own right. It was recognised that ancient woodland was subject to particular pressures and was declining, particularly in eastern England, due to the conversion of semi-natural woodland to plantations and farmland.
The original aims of the AWI were to:
When it was launched in 1981 by the Nature Conservancy Council, the AWI was intended to be an inventory of woods in Great Britain as a whole. Parallel inventories were carried out in Wales and Scotland as well as in England. In 1991 the Nature Conservancy Council was replaced by English Nature. English Nature dealt with nature conservation in England only, and inherited responsibility for the English part of the AWI. Scottish Natural Heritage and the Countryside Council for Wales were established to cover Scotland and Wales, respectively, and appear to have taken over the inventories in their countries.
Context of this recordBrowse by Reference
- FT - Records created or inherited by the Nature Conservancy, the Nature Conservancy Council and English Nature
- Records of the Nature Conservancy, the Nature Conservancy Council and English Nature: Headquarters Records
- FT 43 - Nature Conservancy Council and English Nature: Ancient Woodland Inventory Dataset