The Knockmore Scarpland Biodiversity Profile

Key Characteristics

• woodlands cover about 14% of the LCA of which about two-thirds is coniferous forest in the south
• the most frequent broadleaved woodlands are hazel and ash - hazel woodlands often located beneath limestone scarps
• wet woodlands at foot of scarps and on shores of some loughs
• examples of western upland oakwoods, especially in north of LCAexcellent examples of upland calcareous grasslands and limestone pavements - both rare in Northern Ireland
• fen-meadows and traditionally managed hay meadows, relatively species rich and characteristic of W. Fermanagh
• limited blanket bog and upland heath, but both are Priority Habitats
• rare lake types - oligotrophic, mesotrophic and eutrophic

Woodlands

Woodlands cover about 14% of the LCA of which about two-thirds is coniferous forest in the south. This is dominated by Sitka spruce with lodgepole pine and some Norway spruce and Japanese larch. This is generally of low biodiversity although there are small pockets of hardwoods and records of red squirrel.

The most frequent broadleaved woodlands are hazel and ash - hazel woodlands (upland mixed ashwoods) often located beneath limestone scarps, as for example at Knockmore Cliffs, Gortgor, Oubarraghan and Belmore. The freely-draining limestone soils give rise to a canopy generally dominated by ash with hazel, and occasional rowan and holly in the understorey. Bramble, stone bramble and a diverse fern community form a characteristic field layer. Herbs are very diverse and often dominated by meadowsweet and wood-sorrel, with species such as primrose, barren strawberry, herb-robert and common dog-violet. Other species that commonly occur include great wood-rush, bluebell, wood anemone and ramsons. Bryophytes form a dense carpet over soils and exposed rock faces and boulders. The woods are particularly rich in species that are scarce in Northern Ireland, including toothwort, bird's nest orchid, Welsh poppy, wood fescue, thin-spiked wood sedge and the lichen Lobaria pulmonaria. Epiphytic bryophytes are well-developed throughout the woodlands, which are also important for their exceptionally rich and diverse fungal assemblage. (West Fermanagh Scarplands ASSI and West Fermanagh Scarplands SAC)

Where soils are wet, at the foot of the scarp slopes, wet woodland has developed. This is characterized by alder, goat willow and ash, with creeping buttercup and opposite-leaved golden saxifrage in the herb layer. The diversity and cover of the herb layer is often dependent on the level of grazing. Wet woodland also occurs around the shores of some of the small loughs.

In the north of the LCA the prevailing calcareous soils change to acid soils on sandstone and sandstone till, and on these there are examples of upland oakwood; these include woods at Lenaghan, Carrick Lough, Carnick and part of Largalinny ASSI (and Largalinny SAC) (see also LCA 4). Largalinny ASSI represents bryophyte-rich old sessile oak woods in Northern Ireland although there are also flushes and calcicolous (favouring lime) woodland. A number of rare species, such as serrated wintergreen and the oceanic Tunbridge filmy-fern are found here, as well as a rich bryophyte and lichen flora. Minran Wood is one of the larger oakwoods, birch is abundant and there are frequent ash and hazel, in part reflecting that both acid and more basic soil types are present. The herb layer is of moderate diversity, but mosses and lichens are abundant.

Grassland and Arable

Grassland accounts for 72% of the land cover (similar to the percentage for Northern Ireland as a whole), of which just under a third is improved pasture. This shows a patchy distribution on the lower ground in the east of the LCA and is largely the product of local changes in soil type, relief and management by individual farmers. The more intensely managed, most improved pastures are of low biodiversity, but there is a gradation through to those fields that are traditionally managed for hay and/or low levels of grazing and tend to be more species rich. These also merge with fields that appear to have been abandoned and have been invaded by rushes, alder and other shrubs from surrounding, neglected and overgrown hedges.

Semi-natural grassland communities are complex and reflect the range of soil, topographic and other environmental factors as well as past and present management. Grassland types range from species rich calcareous grasslands on limestone outcrops, to wet, flushed grasslands.

An excellent example of dry calacareous grassland is at Monawilkin ASSI, floristically the richest example of blue moor-grass grassland in Northern Ireland (upland calcareous grasslands). The Monawilkin site is rather different from similar grasslands in the UK in that it includes species such as eyebright. Several distinctive plant communities occur, closely related to variations in steepness of slope, aspect, and soil depth. The range of calcicolous plants includes kidney vetch, crested hair-grass, and wild thyme. Monawilkin is also important for butterflies, including the only known locality for small blues in Northern Ireland. Several areas of such grasslands occur on the limestone soils, sometimes with a ranker growth of grasses, as at Belmore, whereas with shallower soils the grasses are less dominant and herbs such as purging flax, bird's foot trefoil and wild thyme more common.

The Knockmore area supports a range of surface karst topography including some of the finest limestone pavement in Northern Ireland. The grikes (weathered joints) provide a niche for a varied assemblage of ferns and higher plants. Wall-rue, black spleenwort, brittle bladder-fern and hart's-tongue are widespread, as are herb-Robert, wood-sorrel and hazel. The clint surfaces (the limestone blocks or pavement) support typical calcareous grassland.

In damper areas within the LCA, more neutral (mesotrophic) grasslands occur. Some of these are dominated by purple moor-grass within a sedge and herb-rich sward, generally known as 'Fen Meadow'. The LCA contains a significant proportion of the Northern Ireland area of these purple moor-grass and rush pastures, as around Gortgor and Kilgarrow. Characteristic species include meadow thistle, sharp-flowered rush and the moss Breutelia chrysocoma.

Where the soils are not derived from limestone there are wet acid grasslands that are characteristically rush dominated, although some are more species rich marshy grasslands as at Lenaghan.

Heaths and Bogs

The only significant area of blanket bog in the LCA is on Belmore Mountain. Blanket bog is confined in Europe to the northwest margins of the continent, so that Northern Ireland contains not only a large proportion of the UK's and of Ireland's total area of blanket bog, but also is of major importance at a European scale. Blanket bog, and particularly intact blanket bog, in any LCA is therefore of national and international significance. Sites with pool and hummock complexes are especially significant. Blanket bog is home to plant species adapted to the acidic, low nutrient conditions - including common heather, cross-leaved heath, cotton sedges, bog asphodel, deer sedge, bog mosses (Sphagnum species) and sundews. It is also important for over-wintering birds and for breeding birds, including waders. Blanket peat is also important as a store for carbon and as a repository of information on past environments.

Belmore Mountain Bog covers a fairly extensive area, and is generally undisturbed. Peat cutting is for the most part confined to the margins and consists of extensive, but old turf banks, and some localised modern compact harvester cutting. Grazing is more widespread, but it is only in the most accessible parts that localised poaching of the surface becomes evident. Burning is significant across the eastern part of the bog. The vegetation is rather uniform and there is an absence of structural features such as hummocks and pools. The hummocks that are present tend to be dominated by hummock-forming bog mosses (Sphagnum capillifolium and S. subnitens) with some woolly hair moss. Some hummocks show sign of erosion and the evident lack of growth of hummocks, as well as the uniformity of the vegetation, may result from burning.

Upland heathland is scattered in the north of the LCA on flatter areas above cliffs or on dip slopes, as at Largalinny, and around the margins of Belmore Mt. in the south. On the peaty soils common heather is dominant but bilberry is abundant in some areas. The heath grades in some parts into heathy, upland grassland of wavy hair grass and some bracken. Red grouse is recorded from some of the heaths. Upland heathland is a declining habitat in the UK and Ireland as a result of reclamation, forestry, overgrazing and lack of management so that even the small sites in this LCA are of significance not only to the LCA but to Northern Ireland.

Wetlands and Lakes

The majority of lakes in the LCA examined by the Northern Ireland Lakes Survey are mesotrophic, but towards the lower levels of nutrients and bases. Mesotrophic lakes, have 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. Lough Nagor, Belmore Mt., was classed as a bryophyte lake - peaty, low pH lakes that are generally unproductive and typical of peatlands. In contrast, Doagh Lough and Killyhommon Lough are eutrophic standing waters, of a type that is comparatively rare, un-enriched compared with other lowland lakes and with a Fermanagh/ South Tyrone bias.

Several of the loughs have reedbeds, including Loughs Fadd, Doagh, Killyhommon and Carrick and fens are present at Loughs Fadd, Monawilkin, Doagh, Carrick and Killyhommon. Fens also occur in wet flushed areas beneath the limestone scarps, as at Belmore; these fens tend to be rank sedge communities with long-stalked yellow sedge being particularly characteristic. The rare broad-leaved cotton sedge also occurs below the Belmore cliffs.

Key Issues

General actions for UK and NI Priority Habitats and Priority Species are detailed in the Habitat Action Plans and Species Action Plans.

WOODLANDS

Issue: woodland cover of variable biodiversity value, but including significant examples of NI resource of mixed ashwoods and hazel woodlands and some upland oakwood

Actions:

• further study of the history of broadleaved woodlands particularly any ancient and long-established, as a possible key to future management
• encourage control of grazing in broadleaved woodlands to foster herb layer and regeneration and if necessary, encourage replanting of canopy species
• encourage planting of broadleaved woodlands, through appropriate grant schemes, rather than small conifer plantations which are of poor biodiversity and landscape value
• ensure that hazel scrub is not cleared

GRASSLAND AND ARABLE

Issue: varied biodiversity of farmland but including species rich calcareous grasslands, species-rich fen meadows and limestone pavements

Actions:

• maintain and improve field boundaries especially hedgerows in areas of improved pastures . This may be achieved through adoption of correct cutting cycles; hedge laying and replanting where necessary; leaving saplings uncut to develop into hedgerow trees; avoidance of spraying with fertilizers, slurry, herbicides; provision of wildlife strips and conservation headlands around fields; and limitation of field amalgamation
• encourage (through participation in Environmental Schemes) adoption/continuance of less intensive management of pastures to allow reversion to/continuance of more species-rich grassland and protect unsown areas of species-rich grassland including calcareous grassland and fen-meadows
• ensure that wet grasslands, particularly fen-meadow, are not drained, both for their flora and to encourage wetland birds
• consider promoting schemes to encourage adoption of farming practices that would encourage more wetland birds
• ensure protection of limestone pavements and their flora

HEATH AND BOGS

Issue: upland heathland is a habitat under threat in the UK and Ireland and there is a decline in its biodiversity

Actions:

• promote membership of ESA or other environmental schemes through consultation with farmers and thereby
• control grazing intensity on existing heathland to encourage development of heathland and of heather of different ages
• control gazing intensity on some upland grassland to promote return to heathland
• discourage 'reclamation' to pasture fields around the heathland margins
• discourage afforestation

Issue: blanket bogs are of national and international importance, but in this LCA Belmore Mt. Is the only significant area

Actions:

• restore bog habitats through appropriate management which in this LCA could include cessation of burning and limitation of grazing
• prevent new forest planting on blanket bog

WETLANDS

Issue: fens in Northern Ireland are a large proportion of the UK resource, in this LCA they are small and localised around lakes and beneath cliffs

Actions:

• protect fens against loss by drainage and infill, which includes use as official refuse tips as well as sites in which to deposit building rubble and fly-tipping
• leakage of fertilizers and slurry from surrounding agricultural land should be prevented as this increases the nutrient levels and affects species composition
• limit grazing in fens beneath cliffs

Issue: rare oligitrophic, mesotrophic and eutrophic lakes

Actions:

• protect water quality of lakes and rivers through nutrient management and by reducing suspended sediments, thus
• promote and encourage existing good farming practices so that streams are not polluted by run-off from agricultural land or seepage from silage pits
• monitor streams in relation to expansion of rural housing and associated septic tanks/sewage treatment plants
• monitor streams for pH, nutrients and sediment load in relation to forestry activities

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