Data included in the Dictionary

The NBN Habitats Dictionary includes information on 16 classifications in use in UK. In some cases there have been updates to these classifications, and the Habitats Dictionary gives priority to the most recent update while also providing information about earlier versions which might have been used in the past. 7 such obsolete versions are included in the dictionary and are clearly labelled as 'OBSOLETE'.

The main secondary sources of data are the ‘Biotopes Dictionary' of Recorder 2002 and the European Nature Information System (EUNIS) habitat classification. Tables of relationships between classifications have been supplied by JNCC and the EUNIS project.