Bryophyte clusters and sand dune vegetation communities

The National Vegetation Classification (NVC) is a phytosociological treatment of the British vascular and non-vascular vegetation that has been adopted widely. Since its publication between 1991 and 2000 there have been no studies which have attempted to identify clusters of bryophyte species within a site and assess their distribution in relation to NVC communities. The aim of this paper is to undertake such an approach across a variety of sand dune habitats. Detrended Correspondence Analysis (DCA) and cluster analysis utilizing percentage cover data from 97 relevés found seven bryophyte clusters distributed across the study area, which are described in terms of their bryophyte and vascular plant species composition, life-history strategies, life-forms, habitat and NVC communities. Some bryophyte clusters and NVC communities were associated strongly, while in other instances the relationships were less clear. The latter may be due to bryological gaps in the NVC data for sand dune communities and/or variation in bryophyte composition that is not correlated with changes in vascular plant communities. It is concluded that a comprehensive evaluation of the bryological quality of the NVC for habitats that are particularly important for bryophytes may be justified.