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Special Areas of Conservation

Eryri/ Snowdonia

Designated Special Area of Conservation (SAC)
Country Wales
Unitary Authority West Wales and The Valleys
Centroid* SH695658
Latitude 53.17333333
Longitude -3.953333333
SAC EU Code UK0012946
Status Designated Special Area of Conservation (SAC)
Area (ha) 19732.98
* This is the approximate central point of the SAC. In the case of large, linear or composite sites, this may not represent the location where a feature occurs within the SAC.
Location of Eryri/ Snowdonia SAC

General site character

  • Inland water bodies (Standing water, Running water) (2%)
  • Bogs, Marshes, Water fringed vegetation, Fens (15%)
  • Heath, Scrub, Maquis and Garrigue, Phygrana (19.7%)
  • Dry grassland, Steppes (34%)
  • Alpine and sub-Alpine grassland (1%)
  • Broad-leaved deciduous woodland (0.3%)
  • Inland rocks, Screes, Sands, Permanent Snow and ice (27%)
  • Other land (including Towns, Villages, Roads, Waste places, Mines, Industrial sites) (1%)

Download the Standard Data Form for this site (PDF <100kb)

Note When undertaking an appropriate assessment of impacts at a site, all features of European importance (both primary and non-primary) need to be considered.

Annex I habitats that are a primary reason for selection of this site

  • Llyn Idwal, in the mountains of Snowdonia, represents oligotrophic waters (Type 3) in north Wales. It is a relatively small, shallow, upland corrie, in contrast to Llyn Cwellyn, also in Snowdonia, and complete ice cover has been recorded in winter. No overall change in the lake’s water chemistry has been found since the mid-19th century, and the water quality is considered to be high. The site has a good representation of typical plant species, including quillwort Isoetes lacustris, water lobelia Lobelia dortmanna, shoreweed Littorella uniflora, bulbous rush Juncus bulbosus, alternate water-milfoil Myriophyllum alterniflorum and intermediate water-starwort Callitriche hamulata. Bog pondweed Potamogeton polygonifolius has been recorded from stream inlets, and pillwort Pilularia globulifera is reported from this site. Emergent and floating vegetation is mainly confined to the shallow sub-basin at the south end of the site, where floating bur-reed Sparganium angustifolium forms extensive mats, alongside stands of common reed Phragmites australis, water horsetail Equisetum fluviatile and bottle sedge Carex rostrata.

  • Snowdonia has the best-developed and most extensive areas of Siliceous alpine and boreal grasslands in Wales and is the largest example of the habitat type south of Scotland. The principal sub-type present is U10 Carex bigelowiiRacomitrium lanuginosum moss-heath, but there are also fragments of U7 Nardus strictaCarex bigelowii grass-heath. This site is representative of the more impoverished southern variants of the habitat type.

  • Snowdonia is the most southerly site selected and contains the most extensive and diverse examples of hydrophilous tall herb fringe communities in Wales. Fragmentary stands of the habitat type occur on pumice tuff and other base-enriched igneous rocks at a range of altitudes throughout the site. The vegetation is floristically somewhat impoverished compared with Scottish examples but includes many of the species found further north, such as globe-flower Trollius europaeus, wild angelica Angelica sylvestris and holly-fern Polystichum lonchitis. It is important as a southern outlier for arctic-alpines such as alpine saw-wort Saussurea alpina and black alpine-sedge Carex atrata. There are also some southern species, which are absent further north, for example Welsh poppy Meconopsis cambrica.

  • Snowdonia is the largest site in Wales representative of siliceous scree. The site has extensive screes of igneous rocks with large stands of U21 Cryptogramma crispaDeschampsia flexuosa vegetation; associated species include fir clubmoss Huperzia selago. Bryophyte and lichen-dominated screes are also well-represented and include important populations of rare and local montane and oceanic species, such as Marsupella adusta, Marsupella stableri and Cornicularia narmoerica.

  • Snowdonia is representative of Calcareous rocky slopes with chasmophytic vegetation at one of its most southerly outposts in the UK, and contains the most extensive and diverse examples of these communities in Wales. Crevices in base-rich igneous rocks support a characteristic assemblage of plants, with a large number of arctic-alpine species. These include a number of nationally rare species, such as alpine saxifrage Saxifraga nivalis, tufted saxifrage S. cespitosa, alpine meadow-grass Poa alpina and alpine woodsia Woodsia alpina. A species of particular interest is the Snowdon lily Lloydia serotina, which in the UK occurs only in Snowdonia, in rock cracks and crevices on calcareous and more siliceous substrates, and is here at its northern limit in western Europe.

  • Snowdonia, north Wales, is representative of Siliceous rocky slopes with chasmophytic vegetation at the southern edge of the range of the habitat type. Acidic crevice communities occur throughout the site on igneous outcrops and include populations of stiff sedge Carex bigelowii, fir clubmoss Huperzia selago and forked spleenwort Asplenium septentrionale. Atlantic species, including Wilson’s filmy-fern Hymenophyllum wilsonii and a wide range of bryophytes, are also well-represented.

Annex II species that are a primary reason for selection of this site

  • 1393 Slender green feather-moss Drepanocladus (Hamatocaulis) vernicosus

    This is an upland site in north Wales for Slender green feather-moss Drepanocladus vernicosus, which has been recorded in flushes up to an altitude of 450 m.

  • 1831 Floating water-plantain Luronium natans

    Snowdonia in north Wales is an example of a montane lake habitat supporting floating water-plantain Luronium natans. Records date back to the 18th century, indicating that habitat conditions are particularly favourable for this species.

Annex II species present as a qualifying feature, but not a primary reason for site selection

  • Not Applicable

Many designated sites are on private land: the listing of a site in these pages does not imply any right of public access.