Please note: the content of this PDF file is taken from archive holdings, and has been rendered to produce the best possible output. However, you may experience fluctuations in quality due to these files not being created from electronic originals. The Habitats Directive: selection of Special Areas of Conservation in the UK JNCC Report No. 270 Edited by A.E. Brown, A.J. Burn, J.J. Hopkins & S.F. Way Joint Nature Conservation Committee Monkstone House City Road Peterborough PE1 1JY United Kingdom JNCC 1997 Contents Preface ................................................................................................................................................. 5 Acknowledgements .............................................................................................................................. 6 Notes on nomenclature ........................................................................................................................ 7 Part 1: Background to site selection ............................................................................................................... 8 1.1 Introduction .................................................................................................................................. 9 1.2 Establishment of SACs ................................................................................................................. 9 1.3 The EC process and criteria for site selection............................................................................... 10 1.4 The Atlantic Biogeographical Region .......................................................................................... 11 1.5 Summary of site selection principles in the UK ............................................................................ 12 1.6 Habitat types of Community Interest in the UK ........................................................................... 14 1.7 Species of Community Interest in the UK .................................................................................... 15 1.8 Considerations in the UK approach to site selection .................................................................... 16 1.9 Process adopted for site selection in the UK ................................................................................ 18 1.10 UK interpretation of site selection principles ............................................................................ 19 1.10.1 Selection principles for Annex 1 habitat types ........................................................ 19 1.10.2 Selection principles for Annex II species ................................................................ 21 1.10.3 General principles .................................................................................................... 22 1.11 Identifying boundaries .............................................................................................................. 24 Part 2: Annex I habitat type accounts ........................................................................................................... 31 Section 2.1: Coastal and halophytic habitats ....................................................................................... 32 2.1.1 Sandbanks which are slightly covered by sea water all the time (11.25) ................. 32 2.1.2 Estuaries (13.2) ........................................................................................................ 35 2.1.3 Mudflats and sandflats not covered by seawater at low tide (14) ............................ 39 2.1.4 *Lagoons (21) .......................................................................................................... 42 2.1.5 Large shallow inlets and bays (12) .......................................................................... 47 2.1.6 Reefs (11.24) ........................................................................................................... 50 2.1.7 Annual vegetation of drift lines (17.2) ..................................................................... 55 2.1.8 Perennial vegetation of stony banks (17.3) .............................................................. 57 2.1.9 Vegetated sea cliffs of the Atlantic and Baltic coasts (18.21) ................................. 59 2.1.10 Salicornia and other annuals colonising mud and sand (15.11) .............................. 63 2.1.11 Spartina swards (Spartinion) (15.12) ...................................................................... 65 2.1.12 Atlantic salt meadows (Glauco-Puccinellietalia) (15.13) ....................................... 66 2.1.13 *Continental salt meadows (Puccinellietalia distantis) (15.14) .............................. 69 2.1.14 Mediterranean salt meadows (Juncetalia maritimi) (15.15) .................................... 70 2.1.15 Mediterranean and thermo-Atlantic halophilous scrubs (Arthrocnemetalia fructicosae) (15.16) ................................................................................................. 71 Section 2.2: Coastal sand dunes and continental dunes ....................................................................... 72 2.2.1 Embryonic shifting dunes (16.211) ......................................................................... 72 2.2.2 Shifting dunes along the shoreline with Ammophila arenaria (white dunes) (16.212) 75 2.2.3 *Fixed dunes with herbaceous vegetation (grey dunes) (16.221 to 16.227) ............ 78 2.2.4 *Decalcified fixed dunes with Empetrum nigrum (16.23) ....................................... 81 2.2.5 *Eu-Atlantic decalcified fixed dunes (Calluno-Ulicetea) (16.24) ........................... 83 2.2.6 Dunes with Salix arenaria (16.26) .......................................................................... 86 2.2.7 Humid dune slacks (16.31 to 16.35) ........................................................................ 89 2.2.8 Machair (1.A) .......................................................................................................... 92 2.2.9 *Dune juniper thickets (Juniperus spp.) (16.27) ..................................................... 94 2.2.10 Open grassland with Corynephorus and Agrostis of continental dunes (64.1 x 35.2) ............................................................................................................ 95 Section 2.3: Freshwater habitats .......................................................................................................... 96 2.3.1 Oligotrophic waters containing very few minerals of Atlantic sandy plains with amphibious vegetation: Lobelia, Littorella and Isoetes (22.11 x 22.31).......... 96 2.3.2 Oligotrophic waters in medio-European and perialpine areas with amphibious vegetation: Littorella and Isoetes or annual vegetation on exposed banks (Nanocyperetalia) (22.12) + (22.31 & 22.32) ................................. 98 2.3.3 Hard oligo-mesotrophic waters with benthic vegetation of Chara formations (22.12 + 22.44) ...................................................................................... 101 2 2.3.4 Natural eutrophic lakes with Magnopotamion or Hydrocharition-type vegetation (22.13) .................................................................................................... 103 2.3.5 Dystrophic lakes (22.14) ......................................................................................... 105 2.3.6 *Mediterranean temporary ponds (22.34) ............................................................... 107 2.3.7 Floating vegetation of Ranunculus of plain and sub-mountainous rivers (24.4) .................................................................................................................. 108 Section 2.4: Temperate heath and scrub .............................................................................................. 110 2.4.1 Northern Atlantic wet heaths with Erica tetralix (31.11) ........................................ 110 2.4.2 *Southern Atlantic wet heaths with Erica ciliaris and Erica tetralix (31.12) .......... 113 2.4.3 Dry heaths (all subtypes) (31.2) ............................................................................... 114 2.4.4 *Dry coastal heaths with Erica vagans and Ulex maritimus (31.234) ..................... 119 2.4.5 Alpine and subalpine heaths (31.4) ......................................................................... 120 2.4.6 Sub-Arctic willow scrub (31.622) ........................................................................... 125 Section 2.5: Sclerophyllous scrub (Matorral) ...................................................................................... 128 2.5.1 Stable Buxus sempervirens formations on calcareous rock slopes (Berberidion p.) (31.82) .......................................................................................... 128 2.5.2 Juniperus communis formations on heaths or calcareous grasslands (31.88) .......... 129 Section 2.6: Natural and semi-natural grassland formations ................................................................ 132 2.6.1 Calaminarian grasslands (34.2) ............................................................................... 132 2.6.2 Siliceous alpine and boreal grassland (36.32) ......................................................... 134 2.6.3 Alpine calcareous grasslands (36.41 to 36.45) ........................................................ 138 2.6.4 Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) (34.31 to 34.34) ...................................................................