In the following account of this LCA it should be noted that for consistency, the biodiversity section follows the standard order for all LCAs even though some of the communities discussed later may have more importance for biodiversity than those discussed earlier
Key CharacteristicsPartly because of the exposed conditions of this coastal and island LCA, woodland is scarce; it accounts for only around 1% of the land cover. A small fragment of Clare Wood (Forest Service) extends into the LCA near Craiganee. This is entirely of lodgepole pine. Elsewhere in the coastal strip, conifer plantations are small and often act as shelterbelts. At Cregganboy a number of small plantations are scattered through the farmland; Sitka spruce is dominant but there are some broadleaves intermixed, principally ash, sycamore and rowan which grade into the hillside scrub and willows where the soil becomes wetter. On Rathlin, Kinramer FNR includes the whole of the Forest Service property on the island. Experimental attempts to establish woodland on the island produced only patches of deciduous and coniferous scrub. However, these are the only areas of trees on the island and they provide important shelter and nesting sites for small passerines.
Broadleaved woodland is restricted to only a few locations although pockets of scrub are scattered throughout the widespread rocky slopes. These pockets may consist of ash, rowan and hazel, and on wetter ground, willows and alder. The example at Crockacollier is more extensive than many (c.1ha) and is predominantly hazel with standards of ash and sycamore. The wooded cove at Portnakillew is unusual on this predominantly cliffed coast. Sycamore is dominant with wych elm, European larch, ash and alder. There is much gorse along the upper edge of the steep slopes and hawthorn is the main understorey species; saplings of sycamore are frequent. The ground flora is dominated by a carpet of meadow buttercup on the flatter stream-side parts. Epiphytic mosses are common.
Estate woodland is restricted. At Runkerry House in the very exposed conditions, sycamore and wych elm struggle to survive, whereas Beardiville (Lowland woodland pasture and parkland) retains some long-established planting. Nineteenth century planting was dominated by Scots pine and larch with broadleaves intermixed, but there are indications in OS Memoirs that some of the parkland clumps in this seventeenth century demesne may be of a 'more ancient date'. Today, it is dominated by sycamore, with beech, lime, horse chestnut and spruce with an occasional understorey of cherry laurel or rhododendron. To the northeast of the house there is a conifer plantation. Nearby Killygreen is also mainly of conifers.
Grassland and ArableGrassland accounts for c. 61% of the land cover, a much smaller percentage than the average for Northern Ireland (c.71%). Of this, only about half is in improved pastures - again a much lower proportion than for Northern Ireland as a whole (almost three-quarters). Although there are variations in the extent of 'improvement', these pastures generally have low biodiversity as a result of relatively intensive management. Some are sown grasslands dominated by ryegrass and few other species - low biodiversity is in-built. Others have been converted to improved pastures through management. High levels of grazing or repeated cutting for silage, high inputs of fertilizers and slurry, and selective herbicides reduce diversity of both flora and fauna. Within the improved pastures, habitat diversity is increased by small, damp grasslands and, in the southwest, by strips of scrub and rough grassland around former adit mines and quarries. Even on Rathlin Island, the larger part of the enclosed fields has comparatively poor flora, degraded by agricultural improvement, but species rich unimproved grassland survives on steep banks.
Arable land (including grass reseeding) covers 17% of the LCA, almost three times the Northern Ireland average. Arable land is often of low biodiversity interest, but can be significant for farmland birds.
Whereas in many farmlands in Northern Ireland hedges provide much of the plant and animal biodiversity, in this LCA hedges are varied in quality. In some farmland, generally away from the coast and on better land, hedges are well maintained, dense and predominantly of hawthorn. These do provide some biodiversity of plants and animals, particularly farmland birds. Elsewhere, hedges struggle to survive and are often of gorse (whin), reinforced by post and wire. In the rocky parts of the LCA any field boundaries are of stone walls, often in poor repair. However, these areas of rough grazing and heath are of higher biodiversity than the improved pastures.
To the west of Portballintrae, the northern part of the LCA is dominated by rough grazing, which is also extensive around Croyer Hill and Lannimore Hill. In these parts, grass and sedge dominated areas are intermixed with rock outcrops, pockets of peat, damp rushy areas and patches of scrub and heath so that there is not only a diversity of habitats but also of plant and animal species.
On Rathlin Island too there is a complex of habitats with wet and dry heaths, flushed areas and species rich grasslands grading into one another. Most of the formerly enclosed grasslands have a species composition characteristic of unimproved and semi-improved grassland on neutral to mildly acidic soils. There is a diversity of plant and animal species because of this intermix of habitats; however, that also makes it difficult to relate animal and bird species to particular habitats.
Heaths and BogsMuch of Rathlin Island is covered by wet or dry heath (Lowland heathland) with good examples in Ballycarry ASSI, Ballygill North ASSI and Kebble NNR. Common heather is frequent, but western gorse is a feature of the dry heath. There are also pockets of acid grassland, flushes, small wetland areas and ponds within the heath. Many of these have distinctive or rare species. For example, at Kinramer South ASSI, the mosaic of semi-improved acid grassland and heath has pyramidal bugle - the only known locality of the species in Northern Ireland.
On the mainland, heath is intermixed with rough grazing (see above) but is more extensive on rocky areas around Round Hill (south of Portballintrae), on thin peat near Ballynastraid and in Glenamally, and on the slopes surrounding Lannimore Hill. In some cases the thin peat, on which some of the heath has developed, results from past cutting, but in others only peaty soils developed on the rough sloping terrain. However, there are pockets of deeper peat within the heathland. The complex mosaic of habitats (heath/rough grazing/scrub/pockets of peat) has resulted in a relatively high number of records of Priority Species including, Irish hare, linnet, chough, curlew, golden plover, spotted fly- catcher, marsh fritillary butterfly and wall brown butterfly.
There are no extensive peat bogs remaining in the LCA.
Wetlands and LakesOn Rathlin Island, Loughnanskan, Ally Lough and Ushet Lough are all mesotrophic lakes, that is, characterised by having a middle level of nutrients between nutrient poor (oligotrophic) and nutrient rich (eutrophic). Mesotrophic lakes potentially have the highest macrophyte diversity of any lake type. Furthermore, relative to other lake types, they contain a higher proportion of nationally scarce and rare aquatic plants. This is an increasingly rare type of lake in Northern Ireland because the nutrient status of many is being increased through input of water from agricultural land that has had applications of fertilizers and slurry. These three lakes have been classified as Nymphaea / Fontinalis / Littorella, base- and nutrient-poor lakes. There are no significant classified lakes on the mainland part of the LCA.
Only small patches of fen occur in the LCA, some associated with base-rich flushes and small ponds amidst surrounding heathland, as on Rathlin Island and in the rocky upper plateaux of the mainland part of the LCA.
The only significant river in the LCA is the Bush; as a result of glacial activity and deposition many of the small southward-flowing streams are headwaters of the Bush and are therefore important to its water quality and biodiversity. The River Bush has river water-crowfoot as well as the otter and salmonid fish.
CoastalRathlin Island SAC (also Rathlin Island SPA) is surrounded by a wide range of habitats and there is a resultant high species diversity. Along the south-west coast there is a very steep slope of large, stable boulders dominated by the hydroid, Tubularia indivisa, in deeper water and by a diverse assemblage of algae in the shallows. A number of species occur that are rare in Northern Ireland, especially those with south-western distributions, such as the sea-cucumber Holothuria forskal, the sponge Axinella damicornis, and the red alga Drachiella spectabilis. The north-west coast consists of a shallow shelf along the base of the cliffs, followed by a vertical underwater cliff. The cliffs are formed of both chalk (Sub-littoral and littoral chalk sites) and basalt, and support a rich assemblage of sponges and hydroids. To the north-east, the slope offshore is shallower, with the seabed consisting of areas of bedrock interspersed with stable boulder slopes. Sponges are particularly diverse and abundant. In shallow water there are overhangs and surge gullies with characteristic assemblages of species. The south and east coasts are more gently sloping and are mostly dominated by rich hydroid and sponge-dominated biotopes on bedrock, boulders, and cobbles amongst coarse gravel. Frequent components of these biotopes are the hydroids Polyplumaria flabellata, Diphasia alata and the sponge Axinella infundibuliformis.
Above sea level a wide range of maritime cliff and slopes vegetation communities is present. Red fescue is often the dominant species in the grassland communities, while heath is also present in some places. Some species recorded for the site are scarce in Northern Ireland, including common juniper, Scots lovage and roseroot. Partially submerged and submerged caves are common in the cliffs and the sites are used by cave-breeding grey seal.
Rathlin Island qualifies as an SPA and IBA by supporting nationally important numbers of peregrine falcon. Recently chough have also bred on the site, contributing to the maintenance of the chough range in the UK, and there are internationally important breeding numbers of migratory species - razorbill, guillemot and Kittiwake. Generally, the island supports over 20,000 breeding seabirds including some of all-Ireland importance - fulmar, shag, eider, common gull, herring gull, lesser black-backed gull, black guillemot and puffin. The site also regularly supports breeding Manx shearwater.
The North Antrim Coast represents an extensive area of hard cliff along one of the most exposed coastlines in Northern Ireland. The basalt and chalk maritime cliff and slopes support a diverse range of communities including those associated with rock crevices and cliff ledges, and with a range of typical maritime grasslands and heath. Notable species on the basalt cliffs include Wilson's filmy-fern, thyme broomrape, hare's-foot clover, zigzag clover and common juniper. The chalk cliffs support neutral and species-rich calcareous grasslands, the latter particularly where the soil is thin; in some locations overgrazing by sheep has reduced the species diversity. Plants present in the grassland include pignut, harebell, kidney vetch and several orchids including greater butterfly orchid. At White Park Bay, orchids are a significant feature of the grasslands, eight species have been recorded including the frog orchid, pyramidal orchid and small white orchid.
In addition to habitat and plant diversity, the cliffs are important for birds. For example, at Sheep Island ASSI there is second largest coastal colony of breeding cormorant in the British Isles with around 7% of the Irish and 5% of the British population; it is the largest population in Northern Ireland. At the Causeway, both breeding and wintering birds are important, with significant populations of breeding fulmar and black guillemot and most notably, breeding chough.
The north coast also has other important Priority Habitats. Coastal sand dunes are found at White Park Bay and at Bushfoot. At White Park Bay ASSI, there is a narrow belt of sand dunes and also an extensive area of wind-blown sand at the eastern end of the bay. These form part of a matrix of several grassland types that vary according to the substrate, with numerous patches of scrub and some areas of bracken and flushes adding further variety. The mosaic is an important feature, and contributes to the richness of flora and fauna of the ASSI. On the fringe of the dunes and in the areas of wind-blown sand, the calcareous grassland (see above) grades into dune grassland, dominated by marram grass. The dunes also have several specialist invertebrate species. At Runkerry (Bushfoot), the dunes have seaside centaury, confined in Northern Ireland to the sand dunes of the north coast.
Small patches of coastal saltmarsh are located at the Causeway, with saltmarsh flat-sedge a notable species.
Key IssuesGeneral actions for UK and NI Priority Habitats and Priority Species are detailed in the Habitat Action Plans and Species Action Plans.
WOODLANDSIssue: low woodland cover of variable biodiversity value
Actions:
Issue: poor biodiversity of farmland
Actions:
Issue: potential loss of lowland heathland and decline in its biodiversity
Actions:
Issue: important mesotrophic lakes and unpolluted rivers with rare plants and with salmonid fish
Actions:
Issue: impact of recreational activities on coastal habitats
Action: