The following are lists of terms used in connection with the British National Vegetation Classification, together with their meanings.
Communities, subcommunities and variants • A
community is the fundamental unit of categorisation for vegetation. • A
subcommunity is a distinct recognisable subdivision of a community. • A
variant is a further subdivision of a subcommunity.
Constant species • A
constant species in a community is a species that is always present in any given stand of vegetation belonging to that community. For a list of the constant species, and the NVC communities in which they are present, see
List of constant species in the British National Vegetation Classification.
Rare species • A
rare species is a species which is associated with a particular community and is rare nationally. :The sources used by the authors of
British Plant Communities for assessing rarity were as follows. :a) for
vascular plants, two sources were used: ::*Perring, F. H. and S. M. Walters (1962)
Atlas of the British Flora – a species was regarded as rare if it was given an "A" rating in this work (these were plants which Perring & Walters judged to be sufficiently rare to merit a special search in order to ensure all records were included in the atlas). ::*Any species included on lists compiled by the
Nature Conservancy Council of plants found in less than 100
hectads. :b) for
bryophytes, the source used was Corley, M. F. V. and M. O. Hill (1981)
Distribution of bryophytes in the British Isles. This lists the species and the
vice-counties in which they are recorded; presence in under 20 vice-counties was the criterion used for selection as rare. :c) for
lichens, no source was available, and the authors used their own selection of species. For a list of these rare species, and the NVC communities in which they are present, see
List of rare species in the British National Vegetation Classification. == Communities by category ==