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
|2120 "Shifting dunes along the shoreline with Ammophila arenaria (""white dunes"")"|
|The dunes at Crossapol and Feall Bay have the greater part of the mobile dune on Coll, maintained not only by high exposure and good sand supply but by a number of significant blowouts including three very large cauldron blowouts, one of which rises to 35 m O.D. As is frequently the case in western Scotland, there is very little foredune, and the dune front is steep with slumped turfs. Marram Ammophila arenaria dominates the dunes to the extent of being the only species present in some areas, and having only scattered creeping thistle Cirsium arvense and sand couch Elytrigia juncea; lyme-grass Leymus arenarius is absent.|
|2130 "Fixed coastal dunes with herbaceous vegetation (""grey dunes"")" * Priority feature|
|Coll Machair features the highest proportion of semi-fixed dune in western Scotland, which extends as much as 600 m inland, reflecting a combination of high exposure and high moisture levels. Blowout activity is high, perhaps linked to high rabbit Oryctolagus cuniculus numbers; this has given rise to a highly varied dune and 21A0 machair landscape with blowouts in various stages of development and restabilisation, and with the floors of some blowout scars having a high water table. The semi-fixed dune often has a high cover of mosses, mainly Tortula ruralis ssp. ruraliformis.|
|21A0 Machairs (* in Ireland)|
|Coll Machair complex is uncultivated, seasonally grazed in parts and has a high species diversity. The site is a complex of dune, wetland and machair habitats. It has a particularly diverse series of transitions to other habitats because of its complex physical structure. Coll Machair is representative of this habitat type in the Inner Hebrides and is the second-largest area of machair in this part of Scotland. On Totamore Dunes, a foredune ridge is succeeded by a series of erosion and accretion features, dominated by a mosaic of semi-fixed dune and particularly species-rich slack communities. On the landward side, Machair Mhór is the best example of a machair plain on Coll, grading from dry to wet machair and then into swamp communities. In the north the dune system has dammed a valley, resulting in the formation of Loch Ballyhaugh. The Annex II species 1833 Slender naiad Najas flexilis is present, for which the site is also selected. Semi-fixed dune communities dominate Crossapol and Gunna, interspersed with a mosaic of fixed dune communities that are particularly species-rich. On the edge there are transitions from wet machair and dune slacks to wet heath, and a complex of small, species-rich machair lochs.|
Annex I habitats present as a qualifying feature, but not a primary reason for selection of this site
|2190 Humid dune slacks|
|3130 Oligotrophic to mesotrophic standing waters with vegetation of the Littorelletea uniflorae and/or of the Isoëto-Nanojuncetea|
Annex II species that are a primary reason for selection of this site
|1833 Slender naiad Najas flexilis|
|Coll Machair represents slender naiad Najas flexilis in the southern Inner Hebrides. Within the site Loch Ballyhaugh contains a large population of slender naiad, and there is a long history of its presence at this location. The very clear water quality is favourable for the species, and the loch also supports a diverse range of other aquatic and emergent vegetation.|
Annex II species present as a qualifying feature, but not a primary reason for site selection
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