The Lough Navar and Ballintempo Uplands Biodiversity Profile
Key Characteristics
- woodlands account for around 39% of the land cover, a very high percentage compared with that for Northern Ireland as a whole (c. 5.6%). However, this is explained by the large extent of coniferous forest that envelops the plateau surface
- important sites of Priority Woodland Habitats, including western upland oakwoods and upland mixed ashwoods
- species-rich grasslands including both upland calcareous grasslands and 'fen-meadows'
- upland heathlands and scarp vegetation with rare species
- examples of oceanic intact blanket bog
- rare types of mesotrophic lakes, eutrophic lakes and upland oligotrophic lakes
Woodlands
Woodlands account for around 39% of the land cover, a very high percentage compared with that for Northern Ireland as a whole (c. 5.6%). However, this is explained by the large extent of coniferous forest that envelops the plateau surface. Sitka spruce is dominant with lodgepole pine; other species, including broadleaves are in small compartments or are strips of scrub and trees alongside streams or at the foot of scarp slopes and have become surrounded by the forest. These forests are generally of low biodiversity.
Although broadleaved woodlands are generally small, some are important at both the local and national scale. For example, Largalinny ASSI (and Largalinny SAC and nearby Conagher FNR) represents bryophyte-rich old sessile oak woods in Northern Ireland (upland oakwoods). The site contains mixed deciduous woodland in which western oakwood predominates, but there are also flushes and calcicolous (favouring lime) woodland, and there is a transition to open heath. 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. Similar upland oakwood and scrub occurs on the sandstone scarp slopes at Lough Navar. Correl Glen NNR is also an oak woodland with birch and holly; bilberry, mosses and ferns are found in the herb layer on the more acid sandstone soils.
Those parts of the west Fermanagh scarplands with freely draining limestone soils give rise to woodland and scrub that is generally dominated by ash, with hazel, and occasional, rowan and holly, in the understorey (upland mixed ashwoods). Bramble, stone bramble and a diverse fern community form a characteristic field layer with the herbs being diverse in species and often dominated by meadowsweet and wood-sorrel. Typical species include primrose, barren strawberry, herb-robert, common dog-violet, 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. Wet woodlands dominated by alder and downy birch also occur where soils are flushed or waterlogged. (West Fermanagh Scarplands ASSI and West Fermanagh Scarplands SAC)
Grassland and Arable
Grassland covers only about 28% of the LCA, a low figure in comparison with that for Northern Ireland as a whole because of the altitude and westerly location that has given rise to peat and peaty soils - much of which is now covered in forest. Grassland communities are complex and reflect the range of soil, topographic and other environmental factors as well as past and present management. There is only a very limited amount of improved pasture as small pockets around individual farms. Other grassland types range from species rich calcareous grasslands on limestone outcrops, to wet, flushed, more acid grasslands. Some of the latter are dominated by purple moor-grass within a sedge and herb-rich sward, generally known as 'Fen Meadow' (purple moor grass and rush pastures). This purple moor grass - meadow thistle grassland is exceptionally herb- and sedge-rich, ranging from short, grazed swards through to stands that are transitional to scrub and wet heath. Characteristic species include meadow thistle, sharp-flowered rush and the moss Breutelia chrysocoma.
Where the soils are developed from limestone, areas of upland calcareous grassland occur, these are dominated by blue moor grass, glaucous sedge and wild thyme and is largely restricted in Northern Ireland to LCAs in the west of Fermanagh (see also LCA 6).
Heaths and Bogs
The complex topography of the LCA, with numerous cliffs and rocky outcrops separated by flatter areas, has given rise to an intricate pattern of heaths, bogs and acid grasslands. Forestry has further complicated the pattern.
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. It 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.
Most of the remaining blanket bog that is not forested, has been cut-over at some time in the past, but there are a number of intact bogs. Glennasheevar ASSI is a large area of intact oceanic blanket bog exhibiting notable structural features including hummock and lawn complexes and a well-developed pool system. Relatively rare species recorded for the blanket bog include oblong-leaved sundew and the hummock-forming bog moss Sphagnum fuscum. In addition, because of the diversity and quality of the associated habitats present, a number of notable species of Lepidoptera have been recorded. Associated habitats include wet heath communities on the peripheral flushed slopes and dry heaths on shallower peats over rocky knolls.
Lough Naman Bog NNR although recovering from fires in the mid 1970s, is relatively undisturbed. The bog forms a dome in a larger expanse of blanket bog that has been cut-over and planted. Bog cotton and sedges grow on mossy hummocks and there are small pools between. Golden plover, dunlin and red grouse used to breed here; their disappearance from the site and surrounding areas is probably a result of changing land use. A pool and hummock complex can also be seen at Bolusty Beg FNR.
Upland heathland is a declining habitat in the UK and Ireland as a result of reclamation, forestry, overgrazing and lack of management. Upland heathland is scattered throughout the LCA, particularly on sandstone ridges and rocky areas with thin peat and peaty soils. Generally, these heaths are dominated by common heather but there are significant other species. For example at Correl Glen NNR the heathland that occurs between the woodlands has a very diverse lichen flora and at Braade ASSI the slender thread-moss Orthodontium gracile has been recorded, its only known Irish site. This rare plant of sandstone rocks has suffered a severe decline in the last 150 years and has only been seen recently at nine sites in Britain. In addition, Braade is the only known site in Northern Ireland for the arctic alpine species, holly-fern that is scarce and apparently decreasing in Ireland. The fern grows on a small, vegetated scarp strewn with large boulders, on Carboniferous sandstone. Heather and bilberry are dominant along the top of the scarp, with occasional cowberry. Below this on the cliff itself, great wood-rush and bracken are the main components of the vegetation, with species such as golden rod and a wide range of other ferns, including the locally distributed brittle bladder-fern, hay-scented buckler-fern and green spleenwort.
Red grouse, curlew and golden plover are found in the plateau, and there is also a range of other Priority Species including bullfinch, skylark, song thrush, reed bunting and spotted flycatcher.
Wetlands and Lakes
The LCA has a considerable number of lakes many of which are mesotrophic but there are also oligotrophic lakes in the peatlands and naturally eutrophic lakes in the more nutrient- and base-rich areas. Mesotrophic lakes are 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. Mesotrophic lakes in the LCA include those belonging to the Isoetes-Lobelia type, that is contains both type-species, and is rare in Northern Ireland.
Many of the lakes are of the Nymphaea-Nuphar type that is relatively low in nutrients and contains the most diverse macrophytes of upland lakes, but others in the peatlands are even lower in pH and nutrients are generally unproductive. Big Dogs Lough is an example of eutrophic standing waters of a type that is confined to Fermanagh and South Tyrone.
Fens are widespread but individual sites are generally small. Some occur around the loughs, including Big Dogs Lough and Derrynacarbit Lough, whereas others are located at the base of cliffs and scarps where the flushed conditions give rise to diversity of species. Reedbeds are also found around some of the loughs including L. Formal, L. Derrynacarbit, Big Dogs Lough and L. Meenameen.
The loughs and wetlands surrounding them are also important for insects including the Irish damselfly, and several Priority Species of moths and butterflies including argent and sable and the marsh fritillary. Lough Navar, Meenameen Lough and L. Achork have records for the white-clawed crayfish, which is also present in the Sillees River.
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: low native woodland cover but important sites of Priority Habitat types
Actions:
- encourage planting of broadleaved woodlands through appropriate grant scheme
- sensure continued protection of broadleaved woodlands
- discourage further coniferous forest planting
GRASSLAND AND ARABLE
Issue: varied biodiversity of farmland, but including species-rich grasslands and
traditionally managed grasslands
Action:
- encourage (through participation in Environmental Schemes) adoption of less intensive management of pastures to allow reversion to more species-rich grassland and protect unsown areas of species-rich grassland including fen-meadows and calcareous grasslands
HEATH AND BOGS
Issue: upland heathland - a declining UK and Irish habitat
Actions:
- promote membership of ESA and 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
- discourage 'reclamation' to pasture fields around the heathland margins
- discourage afforestation
Issue: examples of intact blanket bog that is of national and international importance
Actions:
- maintain the integrity of existing bogs by for example, preventing infilling, fly-tipping, fires, new drainage and new peat cutting
- prevent new forest planting on blanket bog
WETLANDS
Issue: important lakes - upland oligotrophic, mesotrophic and eutrophic, and rivers with Priority Species
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 effects of peat cutting and forestry activities on pH, nutrients and sediment load and deposition in rivers and lakes
