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 CharacteristicsWoodlands account for around 12% of the land cover, more than double the average for Northern Ireland. Coniferous forest is about half of the woodland, most in Glenarm State Forest. That comprises linear plantations on the slopes above Glenarm demesne. The planting is principally of larch - Japanese, European and hybrid - with some compartments of Sitka spruce and others with an intimate broadleaved mixture that includes oak, beech, sycamore and ash. There are several small conifer plantations within the demesne, principally of larch, Sitka spruce and Norway spruce. A larger plantation at Straidkilly is divided into four adjoining bands on the hillside - at the lower edge a mixed deciduous/conifer band with sycamore, hazel, elder and larch, followed by bands of larch, Lawson cypress, and lodgepole pine on the upper edge. Despite the planted history, the site has a diverse herb flora. In the northern part of the LCA beyond Straidkilly point there are a number of small coniferous plantations but only that on the upper slopes at Drumnasole is of significance. This plantation is surrounded by broadleaved woodland and consists of mature larch with occasional Scots pine, silver fir and beech; the herb layer and ground flora is poor.
Broadleaved and mixed woodland is concentrated in Glenarm, much of it in the demesne (lowland woodland pasture and parkland). The park woodland is located in the northern part of the glen around the castle, boundary walls and along the main estate roads. There is a great diversity of tree species, but amongst the mature trees beech, oak, lime, and horse chestnut are frequent. Small plantations of sub-mature oak and beech also occur. Alongside the Glenarm River, between the Forest Service plantations at the southern end of the glen and the castle, there is approx. 5 km of riverine woodland; ash elm, oak and sycamore are the most common species, with horse chestnut, poplar and lime also present. The herb layer is diverse, in part reflecting the changing ground conditions, particularly wetness.
The Glenarm woodlands also include those alongside steep-sided streams which may have a more natural origin. Some of these have been included in the Glenarm Woods ASSI one of the largest semi-natural woodlands remaining in County Antrim. The ASSI consists of several distinct woodland blocks that are connected along the Glenarm River valley and two of its main tributaries - the Linford Water to the south-east and the Owencloghy Water to the south-west. The woodland is very variable, ranging from acidic, to flushed and base-rich. As a result, it supports a diversity of habitat types and is one of the richest woods for plants in Northern Ireland with a large number of rare species that includes bird cherry, wood crane's-bill, intermediate wintergreen, bird's-nest orchid, toothwort and several grass, rush and horsetail species.
The Linford Water and Owencloughy Water exemplify the variability of habitats. The upstream half of the woodland in the incised valley of the Linford Water is dominated by dense scrub of hazel, mountain ash and willow whereas downstream the eastern slopes are more mature woodland that includes oak, elm, ash and sweet chestnut. The Upper Glenarm (Owencloghy Water) between Mill Bridge and the State Forest has similar woodland dominated by ash and hazel (upland mixed ashwoods) but with local areas of wet woodland with willows and alder, and some species indicative of planting or landscaping. In both of these woodlands there is a diverse herb and ground flora, many veteran and fallen trees and diverse populations of epiphytic mosses, ferns and lichens.
In addition to its botanical interest, the ASSI provides an important habitat for animals. Bat species recorded include Leisler' s bat, Daubenton' s Bat and brown long-eared bat. Breeding birds regularly include the rare wood warbler in addition to a diversity of other passerines and raptors. The invertebrate interest includes the silver-washed fritillary butterfly, which is scarce in eastern counties of Northern Ireland, and two notable Coleoptera species, the beet carrion beetle Aclypea opaca and the rove beetle Gnypeta caerulea. Glenarm Woods also support a diverse community of lower plants, particularly fungi.
The most extensive broadleaved woodlands in Glenarm are located on the hillsides, mainly on the eastern slopes between the riverine woodlands and the coniferous plantations. Hazel is the most abundant tree with alder, ash and birch also common. The frequency of alder and birch indicates locally wet and boggy ground conditions (wet woodland). There are also locally concentrated groupings of oak alongside the main streams (upland oakwood). Active coppicing of hazel and planting of native oaks by the Ulster Wildlife Trust is helping to retain these woodlands.
The woodlands and adjacent grassy slopes of Glenarm have a number of records of important birds, including bullfinch, song thrush, spotted fly-catcher and skylark.
Outside of Glenarm, the most common woodlands are of hazel. Straidkilly ASSI is one of the largest and least disturbed base-rich woodlands in north-east Antrim. It is comprised of a low hazel canopy with occasional rowan and hawthorn and a few standards of ash, goat willow and downy birch scattered throughout. The diverse ground and herb flora displays a transition from more acid community types on the leached upper slopes through to typical base-rich community types on the damper, lower slopes. Rare species recorded for the site include wood vetch, toothwort, bird's-nest orchid and juniper.
Hazel woodlands are extensive in the north of the LCA, particularly on the slopes above Garron Tower (St. MacNissi's School). Here hazel forms the dense canopy with ash, elm, birch and some oaks as emergents. Although the ground and herb flora is varied, it is generally sparse because of grazing and trampling, where better developed it includes anemones, bluebells, ransoms (wood garlic) and primroses. These hazel woodlands continue northward around Garron Point, but as smaller patches, and southward into Drumnasole woods where the hazel canopy gradually merges into the estate woodland (lowland woodland pasture and parkland). On the slopes, this woodland is of ash, beech, oak and larch, but with a range of other tree species present. The shrub layer includes hazel, hawthorn and blackthorn, but in parts has the introduced snowberry. The herb flora also varies depending on the canopy but also on position on the slope; on lower slopes where soils are more basic it can be diverse, but on more acidic soils bracken can dominate. Towards the bottom of the estate, elm, Scots pine, sycamore and beech are dominant. The grounds of St. MacNissi's School comprise the only other significant parkland in the LCA; here fringing woodland is of beech, elm, oak, Scots pine and Corsican pine and some more recent Sitka spruce.
Grassland and ArableGrassland covers c.74% of the LCA and although nearly four-fifths has been classed as improved, included within that are pastures along the coast on base rich soils derived from basalt-mica schist and basalt-chalk mixed tills. Although quite heavily grazed, these pastures are relatively species rich, especially on the steeper slopes, and are particularly notable in spring for primrose and other spring flowering plants. There are also damp pockets within these pastures often dominated by yellow flag iris. At Feystown in Glenarm, careful grazing and cutting regimes have ensured the preservation of a rare remnant of unimproved, herb rich, meadow. During the summer months the abundance of wildflowers attracts many butterflies including green-veined white, orange tip and silver-washed fritillary. Among the key plant species found at the site are wood crane's-bill, meadowsweet and yellow rattle.
Areas of rough grazing are relatively rare in the LCA and most are where the border clips marginal hill land at the edge of the plateau. Where these are damp they can be important sites for waders; for example, at the head of the Linford Water curlew have been recorded. However, the largest area is in Glenarm above the woods to the north of Forking Bridge. These grasslands are also damp, but flushed and base rich. They are characterised by a tall sward of sharp-flowered rush, common sedge, carnation sedge and purple moor-grass. Associated herbs include marsh hawk's-beard, devil's-bit scabious, common valerian and meadowsweet.
Hedges often provide a reservoir of biodiversity in areas of farmland, which are often of low biodiversity. However, in Glenarm fields are generally surrounded by stone walls or post and wire, hedges are limited and there are few hedgerow trees. The mid-valley section of Glencloy with its small fields, does have hedges or boundaries that combine fence and hedge; hawthorn is the most common shrub although gorse and holly are also frequent. Ash is the most common hedgerow tree and almost three quarters of the field boundaries in Glencloy contain trees. Along the coast in the north of the LCA, fields on the flatter surface between the coastal cliffs and the inland basalt and chalk cliffs are large, of improved pastures and many are sown grass mixtures used for silage. These fields have low biodiversity but many are surrounded by hedges, albeit reinforced by post and wire fencing. Hedgerow shrubs are varied, including hawthorn, blackthorn, holly, gorse, hazel and brambles, which provide habitats for animals and insects. The relatively few hedgerow trees are mainly ash.
Heaths and BogsApart from small patches of gorse (whin) around old quarries and on short steep slopes, there is no significant heath in the LCA; nor is there any peat bog.
Wetlands and LakesThere are no significant wetlands in the LCA. Of the rivers draining from the plateau, only the Glenarm has records of Priority Species - the otter and the river jelly lichen. However, sections of the Glenarm River and the Linford Water are of particular interest, representing good examples of fast-flowing, oligo-mesotrophic (low in plant nutrients) rivers. The plant communities are dominated by bryophytes (mosses and liverworts) such as Cinclidotus fontinaloides, Fontinalis antipyretica and Hygrohypnum luridum
CoastalMost of the coast is in boulders, predominantly chalk and comprises one of the Northern Ireland Priority Habitats - sub-littoral and littoral chalk. Littoral chalk characteristically lacks species common on hard rocky shores but can support distinct successive zones of algae and animals. This coast is dominated by fucoids and in places has numerous rock pools rich in flora and fauna. Where there are patches of moving shingle, as at Whitebay Point, faunal diversity is poor. Carnlough Bay is the only significant area of sandy shore where the faunal community consists largely of burrowing amphipods (small crustaceans) and polychaetes (marine worms).
Key Issues.General actions for UK and NI Priority Habitats and Priority Species are detailed in the Habitat Action Plans and Species Action Plans.
WOODLANDSIssue: significant woodland cover, including good examples of Priority types - upland oak woods, upland mixed ash woods, lowland woodland pasture and parkland - as well as extensive hazel woodland
Actions:
Issue: poor biodiversity of farmland, especially of improved pastures
Actions:
Issue: rivers of importance to plant and animal life, including fish and some NI Priority Species.
Actions:
Issues: there are no major issues in the coastal zone of this LCA