Biological components of Sites of Special Scientific Interest in Wales

Abstract

The designation of Sites of Special Scientific Interest (SSSIs) is one of the major statutory measures for wildlife protection in Britain. In this account, procedures for selecting SSSIs are outlined, and the representation of habitats and species in different taxonomic groups which qualify 731 SSSIs notified in Wales (in November 1994) are summarized. Biological SSSIs occupy approximately 9.6% of the total area of Wales. There are significant differences in the numbers and sizes of sites characteristic in the uplands (few large), lowlands (many small) and coast (intermediate). Over 70% of the biological SSSIs have more than one qualifying feature. Most sites (663, 90%) have been selected for one or more habitats, and many sites (328, 45%) have particular species attributes. In relation to their total extent in Wales, some habitats (including ombrotrophic peatland, dwarf-shrub heathland, rich fen and sand dune) have greater proportional representation in SSSIs than others (such as upland grassland, woodland and scrub). These differences reflect conservation priorities for Welsh habitats which are related to the wider British context. As expected, birds and vascular plants contribute to notification of a greater number of sites than other groups; invertebrates, lichens and bryophytes qualify in some sites and require further evaluation in others; except for bats, mammals are comparatively poorly represented as special features. Birds qualify many of the largest SSSIs in Wales (breeding assemblages in the uplands and overwintering wildfowl and waders in estuaries). Possibilities for future refinement of the SSSI series are considered. It is suggested that the establishment of conservation sites is sufficiently advanced in Britain to permit worthwhile examination of the composition and function of the network as a whole against conservation objectives.