Ancient Semi-Natural Woodland (including PAWS and RNWAS) (definition)

Durham Lowland Priority Habitats
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Ancient Semi-Natural Woodland (including PAWS and RNWAS) Habitat Definition


Identification & Mapping

Ancient woodland includes all woodland sites with evidence of continuous wooded cover since 1600 AD. The definition includes Planted Ancient Woodland Sites (PAWS) and restored Native Woodland on Ancient Sites (RNWAS)..

Planted Ancient Woodland Sites (PAWS) are woodland sites which contain evidence of former ancient woodland, or for which there is recorded evidence of former ancient woodland, and which have subsequently been planted with coniferous or broadleaved trees.

Restored Native Woodland on Ancient Sites (RNWAS) are PAWS sites as above which have been restored to native woodland. A PAWS site can be defined as restored if re-establishment of a functioning native woodland ecosystem has been undertaken, both in terms of the woodland structure and its composition. This is undertaken by (as defined by the Forestry Commission 2003):

  • Securing features from the former ancient semi-natural woodland.
  • Removing introduced species of trees, shrubs, and other plants.
  • Encouraging the re-establishment of native species.
  • Initiating or enhancing ecological processes which may be absent or damaged (such as appropriate grazing regimes).

There is a current inventory of ancient woodlands (and PAWS) over 2ha in extent. There are known to be inaccuracies in this inventory and further work is planned to revisit these sites and update the inventory.

Condition Assessment

There is a standard condition assessment for Ancient Woodlands (JNCC 2004*)

Durham BAP has also developed its own ASNW condition assessment based on revised Forestry Commission guidelines and used during the Derwent Valley Ancient Woodland Inventory.

To be in ‘favourable condition’ an ASNW must meet all the conditions below:

  • No loss of woodland area.
  • More than 50% canopy cover.
  • More than 90% native species.
  • More than 20% shrub cover.
  • More than 90% native shrub species.
  • At least 3 fallen trees of >20cm diameter per hectare
  • At least 4 standing dead trees of >20cm diameter per hectare
  • Sufficient young plants to replace the tree cover
  • 90% expected NVC.
  • Veteran Trees to be present.
  • Presence of particular indicator plants
  • Some topographical features to be present.

There will be a baseline for condition for all sites surveyed, but it will be difficult to repeat this work regularly. For sites recorded in unfavourable condition, records of current positive interventions will give the site ‘recovering’ status. (Note: This will only be applied retrospectively once the results of any interventions are known)

*JNCC, (2004) Common Standards Monitoring Guidance for Woodland, Version February 2004, ISSN 1743-8160