Slieve Russel, Derrylin and Kinawley Biodiversity Profile

Key Characteristics

• woodland is scarce in the LCA, limited to small patches on slopes of Slieve Rushen - Molly Mountain, and to cut-over bog
• upland mixed ashwoods, birch and wet woodlands are the most common woodland types, but one or two oakwoods on steep-sided streams
• improved pasture limited in extent, with much reversion (return to former condition) to rushes
• important examples of semi-natural and less-managed grassland types including upland calcareous grasslands and species-rich rush pastures
• most lowland bog has been cut-over, but Moninea Bog of international significance with its intact dome, structural features and flora
• Cladagh River of major significance for rare Priority Species of aquatic flora and fauna

Woodlands

The only area of State forest is Derrylin Wood, which is dominated by Sitka spruce with Norway spruce and Japanese larch. Although the red squirrel is recorded, generally such coniferous forest has low biodiversity.

The middle slopes of the Slieve Rushen and Molly Mountain have thin limestone soils on which there are several small upland mixed ashwoods. Carn Hill Wood and that in Clonturkle to the southwest, is dominated by hazel with frequent ash. Grazing in some parts and the steepness of the boulder slopes in other parts, have resulted in a ground flora that although quite diverse in species, is limited in cover. Wood sorrel, wood anemone and local carpets of bluebell form a large proportion of the cover. Mosses and ferns are abundant. Diversity is increased by small flushed areas of alder and willow in which the herb layer includes opposite-leaved golden saxifrage, marsh hawk's-beard, remote sedge and wood sedge, whilst at the base of the slope, waterlogged soils have creeping buttercup and creeping bent.

Carrickbrack Wood, on the east slopes of Slieve Rushen, also has upland mixed ashwood, although here there are beech and sycamore that suggest some planting may have occurred (a feature of other stream-side woodlands on these slopes). In the upper part of the valley soils become acid and the wood changes to an upland oakwood with abundant birch and a herb layer dominated by dense greater woodrush that has out-competed most other plants. In the uppermost part, the wood thins and beneath the stunted trees there is heath vegetation with bracken, bilberry, tormentil and common bent.

Away from the hill and mountain slopes, woodland is largely confined to that on cut-over bog. Here, on the drier peat left by cutting birch is dominant, with willow and alder in wetter parts, but these wet woodlands are of no great extent. Small wet woodlands also occur alongside rivers and loughs, as at Drumderg Lough; that joins planting around Garvary Lodge, but that planting is very small and the LCA has no examples of estate woodland.

Grassland and Arable

Recent land cover classification of the LCA suggests that nearly two-thirds is in improved pasture, but this is an over-estimate and has taken in extensive areas of rush dominated "grass" fields. Improved pasture is really limited to a central band that extends south of Derrylin and coincides with better-drained brown earths on sands and gravel. (However, many of these pastures have been lost to quarries.) Improved pastures are generally of low biodiversity because many are sown pastures (rye grass mixtures), have applications of fertilizers and slurry, and are either cut for silage or subject to heavy grazing.

Elsewhere the lowlands are divided into small fields that are dominated by rushes, apart from where individual farmers have invested in improvement. These rushy fields are developed over surface gleys with poor or very poor internal drainage and typically have low species diversity. There are some areas with greater diversity, where the common grasses (sweet vernal grass, rough meadow grass, Yorkshire fog and red fescue) are accompanied by crested dog's tail and quaking grass, and the sharp-flowered rush by hard rush. In the typical rushy grassland, sedges are sparse, but in the more diverse areas glaucous sedge is prominent. Herbs include meadow sweet, devil's bit scabious and common spotted orchid.

On the dry limestone soils there are areas of upland calcareous grassland, although much of this has been lost to gorse heath. This grassland is characterized by the presence of mouse-ear hawkweed and blue moor grass that with appropriate grazing can be species rich. In damper, flushed neutral grasslands, a short sedge and rush grassland can develop with meadow thistle as a characteristic species (purple moor grass and rush pastures).

The damp meadows, along with bogs, are important sites for breeding curlew and the farmland in general has records for several Priority Species, including spotted flycatcher, song thrush, skylark, reed bunting and bullfinch.

Heaths and Bogs

Lowland raised bog was once extensive, particularly in the north along the Swanlinbar River and between the drumlins in the south. However, with the exception of Moninea Bog, all have been cut-over and some reclaimed. Some have been colonized by birch and have wet woodland at their edges; they are also important to biodiversity as a habitat for wetland birds including snipe and curlew.

Lowland raised bog is a rare habitat in the UK, and Northern Ireland has a large proportion of that remaining; in particular it has much of the intact lowland bog. In the best examples there is a diversity of structural features including hummocks and hollows and pools that give rise to micro-habitats related especially to the height of the water table. The plant species are adapted not only to the generally waterlogged, acid and low nutrient conditions, but also to these small-scale variations in topography and water level. Typical plant species include bog mosses, deer sedge, cotton sedges, bog asphodel, sundews, cross-leaved heath and common heather. Lowland raised bogs, together with blanket bogs, are an important store of carbon and a repository of environmental and archaeological information.

Moninea Bog SAC (Moninea Bog ASSI) is one of the best remaining examples of a raised bog with an intact dome from the drumlin landscape of southern Northern Ireland. The peatland flora typically supports a high cover of bog-mosses, including the hummock-forming species Sphagnum imbricatum and Sphagnum fuscum and the nationally rare Sphagnum pulchrum. All three native British sundews are present.

Wetlands and Lakes

The Cladagh or Swanlinbar River (Cladagh (Swanlinbar) River SAC also Cladagh (Swanlinbar) River ASSI) rises on Cuilcagh Mountain and flows through County Cavan before crossing the border into County Fermanagh in Northern Ireland, and eventually entering Upper Lough Erne. It is ultra-oligotrophic (acid and nutrient-poor) in its upland reaches within the Republic of Ireland, before gradually becoming mesotrophic and eutrophic through its middle and lower reaches within Northern Ireland (these are included in this LCA). Trees line the lower half of the river where it is slow-flowing, deep and eutrophic and the plants are typical of waters rich in nutrients. Vascular plants are dominant and include stands of broad-leaved pondweed and yellow water-lily. The white-clawed crayfish and freshwater pearl mussel are also found in the Swanlinbar River.

Two lakes were examined by the Northern Ireland Lake Survey, but only one, Drumderg Lough, was a priority habitat. It has been classified as a mesotrophic lake, 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. Drumderg was classed as a 'Nymphae/Fontinalis/Litorella' type that is relatively base and nutrient poor. The lough has associated reedbed and fen communities present; these communities are otherwise rare in the LCA.

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 woodland cover of variable biodiversity value

Actions:

• further study of the history and ecology of broadleaved woodlands particularly any ancient and long-established, as a key to future management
• encourage control of grazing in broadleaved woodlands to foster regeneration and if necessary, encourage replanting of canopy species
• encourage planting of broadleaved woodlands through appropriate grant schemes, rather than the small conifer plantations which are of poor biodiversity and landscape value.
• ensure that wet woodlands and birch woodlands on cut-over bogs are not lost through clearance, drainage, land-fill

GRASSLAND AND ARABLE

Issue: poor biodiversity of farmland, but some important grassland types

Actions:

• maintain and improve field boundaries especially hedgerows . 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 of appropriate management of pastures to allow development to more species-rich grassland and protect unsown areas of species-rich grassland
• in particular, consider removal of gorse from limestone grassland and institution of a suitable grazing regime; protect species-rich wet grasslands by for example, restricting field or arterial drainage, poaching of the ground, land-fill

HEATH AND BOGS

Issue: raised bogs of national and international importance

Actions:

• maintain the integrity of existing lowland raised bogs by for example, preventing infilling, fly-tipping, fires, new drainage and new peat cutting
• consider whether any of cut-over bogs could be restored - through appropriate water level management, removal of individual colonizing trees, and phasing out peat cutting
• prevent new forest planting on raised bog

WETLANDS

Issue: important lake and river

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
• continued monitoring of streams below industrial plants and quarries
• monitor streams in relation to expansion of rural housing and associated septic tanks/sewage treatment plants
• ensure cross-border cooperation to maintain the water quality and populations of rare species of Cladagh River
• ensure that activities (forestry, farming, peat cutting) outside of LCA do not affect the river

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