Blackstairs Mountains SAC Site

wexfordhillwalkingclub 05 Jul , 2016

                                                                                                                             

Blackstairs Mountains SAC Site

The Blackstairs Mountains are located along the border of the Counties Wexford and Carlow, forming a mountain chain that runs in a north-east/south-west direction for approximately 22 km, and includes six peaks over 520 m. The range has a core of granite, and on the Carlow side, erosion has cut deeply into the dome exposing successive layers of granite, giving a steeply stepped slope. On the east side some overlying Ordovician slates and sandstones are evident.

The site is a Special Area of Conservation (SAC) selected for the following habitats and/or species listed on Annex I / II of the E.U. Habitats Directive (* = priority; numbers in brackets are Natura 2000 codes):

[4010] Wet Heath [4030] Dry Heath

The site is important for extensive areas of dry heath. The higher, steeper slopes are covered with a dense, tall carpet dominated by Heather (Calluna vulgaris) and Bilberry (Vacdnium myrtillus), with small amounts of Crowberry (Empetrum nigrum), Bell Heather (Erica cinered) and Cross-leaved Heath (E. tetralix). Occasionally Common Bent (Agrostis capillaris) and Mat-grass (Nardus stricta) are also found. Abundant moss cover is present, particularly in those areas which have escaped burning – species include Racornitrium lanuginosum, Hypnum cupressiforme, Polytrichum commune, Hylocomnium splendens and Rhytidiadelphus squarrosus. Stiff Sedge (Carex bigelowii) occurs on the stony ground on the west side of the range.

Lower down the slopes the heath is dominated by Gorse (Ulex europaeus), with some of the species listed above, along with Heath Bedstraw (Galium saxatile) and Tormentil (Potentilla erecta). Bracken (Pteridium aquilinum) is also abundant on the lower slopes, particularly on the western flanks.

Upland grassland is found on those slopes which have been heavily grazed. Grassland species include Mat-grass and Common Bent. Heath Bedstraw and the mosses H. splendens and R. squarrosus are also found.

Wet heath occurs in mosaic with dry heath towards the base of some of the steeper slopes and is also found outside the western edge of the commonage. Typical species include Purple Moor-grass (Molinia caerulea), bog mosses such as Sphagnum capillifolium and S. palustre, and sometimes Bog Asphodel (Narthecium ossifragum). There are relatively extensive tracts of a peat/heath mosaic on the gentle slopes at the east of the southern section of the site and within the commonage. Cottongrasses

(Eriophorum spp.) are dominant here, with small amounts of Purple Moor-grass and over 90% cover of bog mosses. Some very wet patches with Soft Rush (Juncus effusus) occur.

A series of lowland bogs north of Mount Leinster and around Black Rock Mountain have recently been identified which have considerable local importance. These occur around Ballycrystal, south-west of Black Rock Mountain, where the highest feeders of the Urrin River rise, and around Crann on the north of the Black Rock ridge, where feeders of the Clody River rise just south of the Wexford/Carlow border. In these bogs considerable populations of Cranberry (Vaccinium oxycoccos) occur. The Crann bogs also have abundant Bog-myrtle (Myrica gale), uncommon in the county. Other species of interest that occur in the Urrin and Clody bogs include Marsh St. John’s-wort (Hypericum elodes), Pale Butterwort (Pinguicula lusitanica) and Lesser Skullcap (Scutellaria minor). The Crann bogs include quite extensive stands of Purple Moor-grass, and Water Horsetail (Equisetum fluviatile) is widespread. The bogs are reduced to fragments bordering improved grassland or forestry.

Mount Leinster is the highest mountain of the range (795 m). On the east side of the summit a few plants with arctic or alpine affinities occur such as the scarce Starry Saxifrage (Saxifraga stellaris) and the Stag’s-horn Clubmoss (Lycopodium clavatum).

The headwaters of the Urrin River are included within the site. Habitats along it include patches of deciduous woodland dominated by Downy Birch (Betula pubescens). Further south the woodland becomesTnore dense and consists of Alder (Alnus glutinosa), willows (Salix spp.), Hazel (Corylus avellana) and Holly (Ilex aquifolium). The woodland in the south of the area is comprised of Sessile Oak (Quercus petraea). There are also patches of peaty marsh, with species similar to those listed for the lowland bog.

The scarce species Ivy-leaved Bellflower (Wahlenbergia hederacea) and Mountain Fern (Thelypteris limbosperma) occur along the Urrin River, while Cowberry (Vaccinium vitis-idaea), also a scarce species, is found in heath in a number areas of the site. Small Cudweed (Logfia minima), a Red Data Book species that is protected under the Flora (Protection) Order, 1999), has been recorded in heathy grassland on the site. The rare, Red Data Book species Bird’s-foot (Ornithopus perpusillus) is found in dry, sandy places at Knockroe in Co. Carlow.

Small numbers of Red Grouse use the site – their numbers have declined here in recent years.

Land use within the site is centred on grazing. Overall, sheep numbers are low, though there are some pockets where high numbers are found. In these areas there are patches of bare ground, an abundance of Mat-grass and in some places upland grassland replaces the heath. Burning of the Heather is carried out on what appears to be a rotational basis. Heather is regenerating in the burnt areas. From a distance the age structure is evident in the different hues of brown to be seen. Cattle are out-wintered on the slopes just inside the boundary of the commonage. Severe poaching

is associated with this, especially where supplementary feeding is carried out. Coniferous forestry is present over much of the slopes of the mountain (outside of the site), extending to a height of 640 m north of Mount Leinster.

The Blackstairs Mountains SAC is the only example of moorland above 300 m in Counties Wexford and Carlow. It includes good examples of dry heath, a habitat listed on Annex I of the E.U. Habitats Directive. The plant and animal communities are typical of upland habitats, and the growth of Heather is particularly profuse, rivalling some of the larger areas of Heather cover in Co. Wicklow. The presence of rare and scarce species adds significantly to the conservation value of the site.