Slieve Croob Summits Biodiversity Profile

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 Characteristics

• centred on the Slieve Croob mountain mass with its dominant cover of rough grassland mixed with heath and rocky outcrops
• little peat even at higher altitude and fen confined to a few small patches
• semi-natural woodland scarce and opportunity for new woodland at lower altitudes
• adoption of measures to maintain and re-establish heather cover could be a priority in developing the biodiversity of this LCA

Woodlands

Woodlands occupy just over 3% of the LCA, most of it in Drumkeeragh Forest where Sitka spruce is dominant and accompanied by Scots pine, Norway spruce, lodgepole pine and other more occasional conifers. Elsewhere, semi-natural broadleaved woodland is rare. A sycamore, ash, oak woodland is found at Begny Lake, but it is heavily grazed, and other small patches of scrub-woodland, including small hazel coppices, occur on some of the steeper slopes at lower altitudes on Slieve Croob. Willow and alder trees are found on some of the fens, but there is no extensive wet woodland. Shelterbelts of ash and sycamore with Scots pine and beech surround some farmhouses - both active and abandoned.

Grassland and Arable

Arable land is no more than occasional in this LCA. Grassland accounts for over 85% of the cover, but partly as a result of altitude and soils, over a third of this is in rough grassland. The rough grassland itself varies and not only with physical conditions. There are extensive tracts of acid grassland, especially on the western and southern sides of the mountain mass, but grazing history is in part responsible as can be seen at land-ownership boundaries - to one side of a boundary heather can form a significant part of the cover whereas on the other side, with a history of heavier grazing, grasses dominate and there is little or no heather. On the eastern side of the mountain mass, the terrain is much rockier; unlike the western and southern slopes that seem not to have been glaciated, the eastern slopes were scraped and plucked by ice to leave rocky outcrops and small basins. The rough grassland on the eastern slopes has within it a mix of bracken and gorse among the rocks and damp, peaty hollows and fen.

Hedges form the field boundaries on the deeper soils of the southern and western slopes but they are generally poorly maintained and gappy - most are reinforced with wire. Field reclamation and amalgamation, with consequent loss of hedges, has taken place on some of these slopes. On the eastern slopes walls are more common due to thin rocky soils where it has not been possible to plant hedges. Where hedges occur they are normally accompanied by post and wire fencing.

Heath and Bogs

Blanket bog is not extensive or deep on the Slieve Croob mountain mass on account of only limited height and wetness and the steep slopes. It is confined to the summit of Slieve Croob and Slievenisky and small pockets within the glaciated eastern slopes. Easy access on all sides explains why peatland is cut-over.

Wetlands and Lakes

Patches of fen can be found in flat valley floors, as for example along the stream flowing west from Dunbeg Lough, in pockets in the glaciated eastern slopes and fen and reeds may be found adjacent to some small loughs. Black Lough ASSI is a large, site with a diversity of habitats including not only fen and open water but also rough grassland, some of which is species rich, and heath. The fen has developed in an elongated valley and consists of areas of open water, bottle sedge swamp, fen dominated by bogbean and other areas of more diverse fen that support rare vegetation communities and species. Priority species include Irish damselfly and marsh fritillary butterfly. Some of the fens are gradually being colonised by willow trees, as at Drumboy Hill, whereas others in the lower land to the west have been drained and converted to pasture. This drainage has not always been successful and damp, rushy pastures result; these, with adjacent wetlands provide a habitat for waders.

Rivers in the LCA, including the headwaters of the Lagan, have few records of Priority Species, nevertheless to foster wildlife, water quality must be maintained. There are few obvious threats to water quality except form pollution incidents related to agriculture.

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, predominantly of coniferous woods in Drumkeeragh Forest of poor biodiversity value

Actions:

• enhance the biodiversity value of semi-natural broadleaved woodlands by discouraging felling; halt any further felling or pollarding; by retention of fallen and veteran trees (particularly for bryophytes, ferns, fungi and fauna)
• encourage control of grazing in broadleaved woodlands to foster herb layer and regeneration and if necessary, encourage replanting of canopy species
• further study of the history and ecology of broadleaved woodlands within the LCA, particularly any ancient and long-established, as a key to future management
• enhance biodiversity through measures to improve and extend broadleaved woodlands at lower altitudes, especially from scrub and abandoned shelterbelts, through appropriate grant schemes cover such as The Woodland Grant Scheme or The Farm Woodland Premium Scheme; ensure that hazel scrub is not cleared

GRASSLAND AND ARABLE

Issue: the majority of this LCA is comprised of pastoral grassland, with over a third in rough grassland of variable quality

Actions:

• 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 acid grassland; adoption of grazing regimes under ESA or Moorland Schemes could lead to maintenance or re-establishment of heather cover
• maintain and improve field boundaries, especially hedgerows where they occur through adoption of correct cutting cycles; hedge laying and replanting of hedges on the western and southern slopes; leave saplings uncut to develop into hedgerow trees; avoidance of spraying with fertilisers, slurry, herbicides; provision of wildlife strips and conservation headlands around fields; and limitation of field amalgamation
• maintain and enhance damp grassland among fen and peaty hollows by where, possible, restricting field or arterial drainage
• ensure that further clearance of boulders does not occur on pastoral or arable land

HEATHS AND BOGS

Issue: blanket bogs on Slieve Croob and Slievenisky are NI Priority Habitats and are of national and international importance

Actions:

• maintain the integrity of existing blanket bogs by for example, preventing infilling, fly-tipping, fires, new drainage and mechanised peat cutting - applies particularly to intact bogs but cut-over bogs can provide important habitats for birds and invertebrates
• consider restoration of blanket bog habitats through appropriate water level management, removal of individual colonising trees and phasing out peat cutting - applies particularly to formerly intact bogs affected by recent mechanical cutting
• prevent new forest planting on blanket bogs, especially that which could be restored to active growth
• monitor use of cut-over blanket bog to ensure that important micro-habitats are not lost, that the large tracts of land required by predator birds are not broken up by planting and other uses, and that the needs of over-wintering and breeding wetland birds are met

WETLANDS AND LAKES

Issue: important examples of NI Priority Habitat fens and rivers, requiring maintenance of water quality. Black Lough ASSI features a number of NI Priority Species.

Actions:

• prevent further loss of fens such as Black Lough ASSI, through drainage, reclamation, land-fill and encroachment by scrub woodland; prevent dumping and fly-tipping and encourage removal of rubbish; divert the inflow of nutrient rich water from agricultural land into fens
• promote and encourage existing good farming practices so that rivers are not polluted by releases from silage effluent, herbicides, pesticides, fertilisers or sheep dip
• monitor streams in relation to expansion of rural/urban housing and associated septic tanks/sewage treatment plants
• recognise that monitoring of streams in relation to forestry and other operations upstream may be important

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