Y Twyni o Abermenai i Aberffraw/ Abermenai to Aberffraw Dunes
|Unitary Authority||West Wales and The Valleys|
|SAC EU Code||UK0020021|
|Status||Designated Special Area of Conservation (SAC)|
|* 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.|
General site character
Coastal sand dunes, Sand beaches, Machair (55%)
Shingle, Sea cliffs, Islets (2.9%)
Inland water bodies (Standing water, Running water) (2.6%)
Bogs, Marshes, Water fringed vegetation, Fens (0.3%)
Heath, Scrub, Maquis and Garrigue, Phygrana (1.4%)
Coniferous woodland (37.8%)
Download the Standard Data Form for this site as submitted to Europe (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
Abermenai to Aberffraw Dunes is one of two sites selected to represent Embryonic shifting dunes in north Wales. Embryonic dunes form a zone across a broad part of the beach/dune interface, making this site one of the most extensive examples of this habitat type in the UK. It is a site where, in contrast to some others in north Wales, recreational damage is minimal.
Abermenai to Aberffraw Dunes is one of two sites selected in north Wales. It contains one of the largest areas of lyme-grass Leymus arenarius shifting dune community in Wales. The mobile dunes at the southern end of the site support an abundance of sea-holly Eryngium maritimum, and there is well-developed zonation of dune types, including both seaward transitions between mobile dune and foredune, and landward transitions to fixed dune and dune slack.
2130 "Fixed coastal dunes with herbaceous vegetation (""grey dunes"")" * Priority feature
Within this dune complex in north Wales are extensive areas of both fixed dune vegetation with red fescue Festuca rubra and lady’s bedstraw Galium verum and semi-fixed dune grassland with marram Ammophila arenaria and red fescue. Despite the fact that a large proportion of the open vegetation has been afforested, the remaining communities retain considerable interest. Notable species of the site include early sand-grass Mibora minima. On the south side of Menai Strait, the dunes at Morfa Dinlle include a lichen-rich community with Coelocaulon aculeatum (SD11), a type of vegetation which is very rare in Wales.
Abermenai to Aberffraw Dunes in north Wales comprises an extensive area of dunes with a complete range of dune vegetation, including substantial areas of slack vegetation dominated by creeping willow Salix repens ssp. argentea. Despite the extent of afforestation, the dune aquifer retains its overall integrity, although changes in water table, partly attributable to the growth of the forest, have influenced the development of the dune slacks. There is long-term potential for further improvement.
2190 Humid dune slacks
Abermenai to Aberffraw Dunes represents Humid dune slacks in north Wales. There are large areas of open dune vegetation and many Humid dune slacks remain, although there have been changes in the water table that are partly attributable to the growth of the commercial forest. The changes have influenced the development of humid dune slacks, which nonetheless retain most the essential features of the habitat type.
Annex I habitats present as a qualifying feature, but not a primary reason for selection of this site
Annex II species that are a primary reason for selection of this site
1395 Petalwort Petalophyllum ralfsii
Abermenai to Aberffraw Dunes is an extensive complex of sand dunes, dune slacks, marsh, shingle and cliffs in south-west Anglesey, north Wales. There is a large population of petalwort Petalophyllum ralfsii here that was first recorded in 1828. This historical continuity indicates that the site is especially favourable for the survival of this species. Although partly afforested, the open dunes have a very rich bryophyte flora, including the mosses Amblyodon dealbatus, Catoscopium nigritum and the liverwort Southbya tophacea, particularly in damp, calcareous slacks and flats.
1441 Shore dock Rumex rupestris
Abermenai to Aberffraw Dunes in north Wales is important as it represents shore dock Rumex rupestris at the far north-west of its geographical range. It is remote from other known sites for this species, and shore dock occurs in an unusual situation: along a small stream bed and on damp pond edges, formerly in duneland, now in a clearing in a conifer plantation. There are two small colonies, which held 21 flowering plants in 1994, 26 in 1995 and 53 in 1996.
Annex II species present as a qualifying feature, but not a primary reason for site selection
- Not Applicable
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