The statistics presented in the Environment chapter of this release cover:
- ancient and semi-natural woodland;
- protected forest areas;
- populations of wild birds; and
- woodland vegetation.
Data sources and methodology
Ancient and semi-natural woodland and protected areas
The information in Table 5.2 and most of Table 5.1 has been reproduced from Pryor and Peterken (2001). It had been derived from a variety of sources, and is unlikely to give a wholly accurate inventory of protected areas in the United Kingdom.
The woodland categories used in Table 5.1 are:
- ASNW: Ancient Semi-Natural Woodland (both ancient and semi-natural);
- PAWS: Plantation on an Ancient Woodland Site (ancient in the sense of continuously wooded over a long period but not semi-natural);
- OSNW: Other Semi-Natural Woodland (semi-natural but not ancient).
The types of statutory protection in Table 5.2 are:
- SAC: Special Area of Conservation;
- SPA: Special Protection Area;
- NNR: National Nature Reserve;
- SSSI: Site of Special Scientific Interest (ASSI in Northern Ireland).
Data about the small amount of ancient woodland in Northern Ireland was not available in 2001, but has been added using the report "Back on the Map" (Woodland Trust, 2007).
Revised estimates for Wales were compiled for the "Woodland for Wales progress report 2001-05" (2006). In this edition of Forestry Statistics, they have been used for Wales in place of the estimates from Pryor & Peterken (2001), and the UK totals have been revised accordingly.
The UK Indicators of Sustainable Forestry (indicator B1) published in 2002 used results from a different source (Pryor & Smith 2002). This was an updated estimate of ancient woodland area derived by overlaying the 1995-99 National Inventory of Woodland and Trees digital map onto ancient woodland inventories. This gave lower figures than those published in Pryor & Peterken (2001). At the time, Pryor & Smith (2002) was thought to give the best estimates of ancient woodland area. However, further investigation of the discrepancies between the 1995-99 National Inventory of Woodland and Trees and the ancient woodland inventories suggests that some discrepancies are due to differences in spatial registration of woods, and that some areas of ancient woodland are incorrectly omitted from the totals in Pryor & Smith (2002). In consequence, the estimates from Pryor & Peterken (2001) are now recommended for use, until better information becomes available.
The Ancient Woodland Inventory datasets for England and Wales are currently being revised. New estimates for Scotland will become available from the Native Woodland Survey of Scotland.
Populations of wild birds
Population indices for wild birds are a framework indicator for sustainable development. The data published here are based on those published in the Wild bird populations in the UK 1970-2010 statistics release (Defra, November 2011), rescaled here to give year 2000 = 100 instead of year 1970 = 100.
The index for woodland specialists was recalculated in 2007 to include 4 additional species; this affected the indices for total woodland birds and (to a lesser extent) all birds.
Figures showing the overall condition and richness of flora in woodland are derived from data collected by the Countryside Survey in 2007 and previous surveys in 1998 and 1990. Results were published in late 2008 (www.countrysidesurvey.org.uk).
Please refer to the Countryside Survey website for an explanation of the vegetation richness and condition scores.
No similar samples were taken in the Northern Ireland Countryside Survey.
Department for Environment, Food and Rural Affairs (2011) "Wild bird populations in the UK 1970-2010", National Statistics Release (www.defra.gov.uk/statistics/environment/biodiversity/wild-bird-populations-in-uk-1970-2010)
Forestry Commission Wales (2006) "Woodland for Wales progress report 2001-05" (www.forestry.gov.uk/forestry/infd-87kadw)
Pryor, S.N. & Smith, S. (2002) "The area and composition of plantations on ancient woodland sites", Oxford Forestry Institute and Woodland Trust (http://visitwoods.org.uk/SiteCollectionDocuments/pdf/Area_and_Comp_report2.pdf)
Pryor, S. & Peterken, G. (2001) "Protected forest areas in the UK; a report prepared for the WWF and Forestry Commission", Oxford Forestry Institute, Oxford (www.forestry.gov.uk/pdf/ProtectedForest_AreaReport.pdf/$FILE/ProtectedForest_AreaReport.pdf)
Woodland Trust (2007) "Back on the Map" (www.backonthemap.org.uk)
Limited data are currently available on the environmental aspects of woodlands. Other than Wild Bird Populations, all of the statistics in this chapter are outside the scope of National Statistics, but are included here to give a broad indication of the woodland environment.
Statistics on the environment obtained from others are subject to revision whenever the source data are revised.
The Forestry Commission’s revisions policy sets out how revisions and errors to these statistics are dealt with, and can be found at: www.forestry.gov.uk/pdf/FCrevisions.pdf/$FILE/FCrevisions.pdf
For information on the release schedules of statistics produced by others, see relevant websites (above).
"Forestry Statistics 2013" and "Forestry Facts & Figures 2013" will be released on 26 September 2013.