BIOLOGICAL COMPONENTS OF SITES OF SPECIAL SCIENTIFIC INTEREST IN WALES

The designation of Sites of Special Scientific Interest (SSSIs) is one of the major statutory measures for wildlife protection in Britain. I n this account, procedures for selecting SSSIs are outlined, and the r epresentation of habitats and species in different taxonomic groups wh ich qualify 731 SSSIs notified in Wales (in November 1994) are summari zed. Biological SSSIs occupy approximately 9.6% of the total area of W ales. There are significant differences in the numbers and sizes of si tes characteristic in the uplands (few large), lowlands (many small) a nd coast (intermediate). Over 70% of the biological SSSIs have more th an one qualifying feature. Most sites (663, 90%) have been selected fo r one or more habitats, and many sites (328, 45%) have particular spec ies attributes. In relation to their total extent in Wales, some habit ats (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 differenc es reflect conservation priorities for Welsh habitats which are relate d to the wider British context. As expected, birds and vascular plants contribute to notification of a greater number of sites than other gr oups; invertebrates, lichens and bryophytes qualify in some sites and require further evaluation in others; except for bats, mammals are com paratively 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 fu ture refinement of the SSSI series are considered. It is suggested tha t the establishment of conservation sites is sufficiently advanced in Britain to permit worthwhile examination of the composition and functi on of the network as a whole against conservation objectives.