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| Ancient Woodland Inventory (Provisional) for England
- Digital Boundaries. |
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| Introduction |
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| The following information is designed to help you understand the Ancient Woodlands Inventory dataset, its limitations and conditions of use.
Natural England would be pleased to receive information regarding proposed amendments to the Inventory Database or digital boundaries, where these are based on new survey, map or other information. Contact details are given at the end of this document.
If you wish to view the ancient woodland inventory, it is possible to do this online, without downloading it. This can be done from the MAGIC website, www.magic.gov.uk. To view the ancient woodland inventory, follow the link for "Interactive Map", and under Step 1, select "Habitat Inventories". Under step 2, you can choose where you want to look; when the map appears, if you have selected a whole county, you may have to "zoom in" before the ancient woodland layer is visible.
Natural England has some guidance for Local Authorities referring to ancient woodland and planning, which is available here. |
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| Changes to the Digitised Maps |
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The Ancient Woodland Inventory has now been available online since 1999, and in that time usage has been very high. Users have informed Natural England, via the feedback form, of errors in the digital dataset. This has been investigated, and serious errors were identified.
A project to update the Ancient Woodland Inventory boundaries has been completed, and includes recent county updates from Dorset (2001; ENRR 558) and Kent (2002), and surveys of the Forest Enterprise estate across England (1999), as well as matching the older data to the Forestry Commission?s more recent National Inventory of Woodland and Trees. The boundaries are now in line with OS MasterMap, and will be more consistent with other habitat datasets.
Natural England anticipates that this new dataset will require user-verification, and believes that the biggest issue will be the classification of the data into ancient semi-natural woodland or plantation on ancient woodland sites (see definitions, below). Natural England welcomes your feedback on this issue.
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| New project data |
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The ancient woodland inventory has taken two hectares as the minimum area that has been mapped, although where areas have been lost, the remaining area, albeit less than two hectares, has remained on the inventory.
The Weald Ancient Woodland Survey in Sussex has recently remapped all the ancient woodland, taking into account survey and historic maps, and crucially, has also included areas under two hectares. This dataset has not yet been incorporated into the Ancient Woodland Inventory online data; however, it is the intention to include all of it shortly. Other projects that may seek similar aims should contact Emma Goldberg in the first instance to discuss the data specification that Natural England will require to incorporate the data. |
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| Definitions |
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Ancient Woodland
Land that has had continuous woodland cover since at least 1600 AD and may be:
Ancient semi-natural woodland - ancient woodland sites that have retained the native tree and shrub cover that has not been planted, although it may have been managed by coppicing or felling and allowed to regenerate naturally.
Ancient replanted woodland - ancient woodland sites where the original native tree cover has been felled and replaced by planting, usually with conifers and usually this century. |
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| The Ancient Woodland Inventory for England |
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| The inventory identifies over 22,000 ancient woodland sites in England. Ancient woodland is identified using presence or absence of woods from old maps, information about the wood's name, shape, internal boundaries, location relative to other features, ground survey, and aerial photography. The information recorded about each wood and stored on the Inventory Database includes its grid reference, its area in hectares and how much is semi-natural or replanted. Prior to the digitisation of the boundaries, only paper maps depicting each ancient wood at 1:50 000 scale were available. |
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| Limitations of the Ancient Woodland Inventory |
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Only ancient woodland sites that were over 2 ha on the 1920's base maps are included on the Inventory.
Some of these may now be less than 2ha because of subsequent clearance. Woods that were less than 2ha on the base maps are not included even though some of these are ancient. The inventory is classed as "provisional" because it is under a constant system of review and update as new information is received or actual changes are recorded. If you have information that would help us to update the inventory please let us know. |
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| Digital Data |
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Coverage
All existing sites recorded on the Inventory Database have been digitised. Two types of boundaries are depicted: those for semi-natural ancient woodland (dark green cross-hatched) and those for replanted ancient woodland (lime green cross-hatched). |
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Data Structure
The digital woodland boundaries are recorded in a field called ?ThemeName? which has two values, Ancient Semi Natural Woodland or Ancient Replanted Woodland (now known as Plantation on Ancient Woodland Sites). A wood may have several component parts or polygons, representing different areas. There may be discrepancies between the area figures associated with the digital boundaries and those previously recorded on the Inventory Database. Such discrepancies relate to the methods used to calculate areas: digital versus manual, respectively.
N.B. The POLYGONID as an attribute will not be maintained, therefore please do not use this as a linking ID to other data. |
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Scale of Data Capture
The ancient woodland boundaries are digitised to OS MasterMap. However, the maps that they are based upon include the OS 1 First Edition maps, the OS 1:25 000 and the OS 1:50 000 maps. The boundaries cannot be taken as precise, especially where they are surrounded by woodland, and are only precisely comparable with other boundaries at the 1 map scale (1:63 360). |
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MapInfo Tab format
Ancient & Semi-Natural Woodland polygons are green cross-hatched pattern.
Plantation on Ancient Woodland Site polygons are red dotted pattern.
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| Data supplied |
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| The data is available from 26 files based on the Ordnance Survey Grid Letters (sometimes referred to as "military letters"). The data has been split in such a way that the tiles do not cut through any part of any site i.e. the site will lie in whichever tile holds the majority of its area. |
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| Formats |
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MapInfo Tab (Version 8.0)
MapInfo Mid/Mif (Version 8.0)
AutoCAD DXF (Version 12)
ESRI Shp (Arcview Version 3.0) |
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| Attribute information |
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This is a short explanation of what the attributes on the polygons mean. The attribute name given in upper and lower case (e.g. Ancient_woodland_name) is as it appears in MapInfo Tab, MapInfo Mid/Mif and AutoCAD DXF formats. The attribute name given after this in brackets and upper case only (e.g. NAME) is as it appears in ESRI Shp format.
- Ancient_woodland_name (NAME): The name of the ancient woodland. This requires confirmation.
- PolygonID (POLYGONID): The ID of the polygon (this is non unique).
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Theme (THEME): The data theme, in this case it is ANCIENT WOODLAND (with other types of Natural England data download the theme might be SSSI or SAC.)
- Theme_Name (THEMNAME): Whether the area is Plantation on Ancient Woodland Sites or Ancient & Semi-Natural Woodland.
- ThemeID (THEMID): A unique identifier for the wood (not the polygon).
- ExternalID (EXTERNALID): Links to an internal database in Natural England.
- Status (STATUS): The abbreviated Theme_Name, i.e. PAWS or ASNW.
- Perimeter (PERIMETER): The perimeter of the polygon in metres.
- Area (AREA): The area of the polygon in hectares.
- GridRef (GRIDREF): The grid reference of the centroid of the polygon or of a point guaranteed to be within the polygon if the centroid does not fall in the polygon.
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| Copyright |
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The Ancient Woodland Inventory database and digital boundaries are the property of Natural England. Natural England should be acknowledged in any work using this data. The data must not be sold to other parties. Natural England accepts no responsibility for any legal action arising from the use of this data. The data is also classed by Ordnance Survey as derived data which requires you to accept the click wrap licence agreement found in the zip file. |
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| Further Information |
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A variety of publications regarding ancient woodlands are available from Natural England's Enquiries Service (0845 600 3078):
- Reid CM (1997) Guidelines for Identifying ancient woodland. English Nature booklet
- Reid CM (1997) Local Authorities and the protection and management of ancient woodland. English Nature Research Report No.250
- Reid CM (1999) Help notes for planning consultation on ancient woodland. English Nature booklet
- Reid CM, Iles VH & Isaacs J (1999) The ancient woodland inventory database and digital boundary project. An update of recent developments. English Nature Research Report No.313
- Forrest A (2001) The status and distribution of ancient woodland in Dorset Part 1: Details of methods used in updating the status and distribution of ancient woodland. English Nature Research Report 558,
- Westaway S (2006) Weald Ancient Woodland Survey; revised Ancient Woodland Inventory for Wealden District, Final Report. High Weald AONB Unit, Flimwell
- Goldberg E (2006) Ancient woodland: guidance material for local authorities.
Background to how the data was collected is contained in the following scientific paper: - Spencer J W & Kirby K J (1992) An inventory of ancient woodland for England and Wales. Biological Conservation, 62, 77-93
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| Contact details |
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- For specific enquiries regarding technical information about the digital boundaries contact Steve Edge (01733 455332)
- For other information regarding the database, digital boundaries or feedback on this Website please contact Emma Goldberg (01733 455367)
- For written enquiries contact Emma Goldberg, Natural England, Northminster House, Peterborough, PE1 1UA
You can also use our feedback form. |
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