Irvinestown Farmland Biodiversity Profile
In the following account it should be noted that for consistency, the biodiversity section follows a 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
- woodlands cover less than 2% of the LCA, a low percentage even for Northern Ireland (c.5.6%)
- woodland is almost equally divided between coniferous forest and broadleaved/mixed woodland
- broadleaved woodland associated with demesnes, especially Castle Irvine, some wooded streams with mixed ashwoods, and birch woodland on relatively dry cut-over bog; much of the woodland in estates and along streams is at least 'long-established' and may be more diverse than more recent woodland
- grassland accounts for over 90% of the land cover, compared with the c.71% for Northern Ireland as a whole. Three-quarters of this grassland is improved pasture of low biodiversity
- wet grasslands between drumlins and associated with cut-over bog; rushy grasslands on the higher ground of the northwest
- intact lowland raised bog, rare in the UK, in the extreme east and north - notably Tonaghbeg ASSI
- rare lake types - mesotrophic, eutrophic and marl lakes
- Ballinamallard River has relatively rare Priority Species and part of scheme to enhance salmon in the Erne system.
Woodlands
Woodlands cover less than 2% of the LCA, a low percentage even for Northern Ireland (c.5.6%); woodland is almost equally divided between coniferous forest and broadleaved/mixed woodland. With the exception of Necarne Forest, coniferous forest is located in the east in parts of Tillick and Pigeon Top Forests. Sitka spruce and Norway spruce are dominant with compartments of lodgepole pine and of Japenese larch also common. The biodiversity of these forests is generally low although small compartments of hardwoods and patches of scrub may be of more interest. Necarne Forest, occupying the southern half of the Castle Irvine demesne, has several named woods; Dorue Wood is predominantly conifers (Sitka and Norway spruce, lodgepole pine and Japanes larch), as is the edge of Mulloch Moss Wood, but the remaining woods are broadleaves, mainly oak with ash, sycamore, alder and willow. The northern part of Castle Irvine demesne, not Forest Service, (lowland woodland pasture and parkland) has similar broadleaved species. Much of the present woodland in the northern half of the demesne, some of the fringes of that in the southern half and Derrynanny Wood, are shown on the 1834 6" OS maps so that the woods are at least 'long-established'. The herb layer is of moderate diversity and lichens and mosses are abundant.
Most other demesnes and parklands are small, but many were present in 1834 and in view of their long existence may have species not found in more recent woods. Examples include Kiltierney Abbey grounds, where oak is dominant with sycamore, alder, ash and willow also present, Crocknacrieve and Lake Mount.
Between Ballinamallard and Magheracross, the Ballinamallard River has several patches of woodland which together may be regarded as upland mixed ashwoods; ash is dominant with birch and sycamore. Much of the woodland was present in 1834 and although the presence of beech indicates some landscaping activity, probably associated with Jamestown House, the woodland is at least 'long-established' and parts may be ancient. Corkragh Wood, a little further upstream, also appears to have been landscaped and extended although much of the woodland was present in 1833; it has much beech, oak, ash and sycamore as well as a small amount of plantation conifer, and an understorey that is dominated in parts by cherry laurel.
Wet woodland is confined to small patches, often at the edge of cut-over bogs where cutting has removed the acid peat to leave wet soils fed by mineral ground water; willows and alder dominate. The drier cut-over bog surfaces have frequently become colonized by birch. Abandoned quarries in the north are being colonised by hazel scrub and woodland.
Grassland and Arable
Grassland accounts for over 90% of the land cover, compared with the c.71% for Northern Ireland as a whole. Three-quarters of this grassland is improved pastures. These have generally low biodiversity as a result of relatively intensive management. Some of the pastures are sown grasslands dominated by ryegrass and few other species - low biodiversity is in-built. Other grasslands have been converted to improved pastures through management. High levels of grazing or repeated cutting for silage, high inputs of fertilizers and slurry, and selective herbicides serve to reduce diversity of both flora and fauna. Arable land accounts for less than 2% of the land cover.
Biodiversity in areas of improved pastures and arable is often concentrated in hedgerows. Indeed, they may be the most significant wildlife habitat over much of lowland Northern Ireland, especially where there are few semi-natural habitats. 
Hedgerows are a refuge for many woodland and farmland plants and animals. In this LCA hedgerows are generally poorly-managed, especially in areas of less productive pasture, where they are overgrown and gappy.
Wet grassland is common on the low ground between drumlins and often associated with cut-over and cut-out former lowland peat bog. These wet grasslands are important habitats for breeding waders; lapwing, snipe and curlew have been recorded from such sites in the LCA. On the higher ground of the northwest many of the fields have become infested with rushes and on the thin humic rankers there is some mix of heathland plants. The Irish hare has also found refuge in these less-managed grasslands.
Although improved grassland dominates the landscape, the inter-mix of other cover types in the farmland, including wet grassland, cut-over bog, small woods and hedges, provide habitats for several of the bird Priority Species, including, song thrush, skylark, spotted flycatcher, reed bunting, bullfinch and linnet.
Heaths and Bogs
Cut-over lowland raised bog is widespread in inter-drumlin hollows throughout the LCA, but intact lowland raised bog is scarce and confined to the extreme east and north. 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 that are 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.
Tonnagh Beg Bog ASSI is a large, relatively intact lowland raised bog which is among the best remaining examples in the west of Northern Ireland.
The intact surface exhibits a well defined dome with characteristic vegetation and structural features, including hummock and lawn complexes and small shallow pools. Bog mosses (Sphagnum species) are well represented, including a very high frequency of the rare Sphagnum imbricatum and Sphagnum fuscum, which form well-developed hummocks over the wet surface.
Around the intact bog peat has been cut for turf in the past creating a mosaic of habitats ranging from acid grassland to small pockets of birch and willow scrub.
Smaller intact bogs nearby include those at Milltown and Sesslagh.
In the north two parts of Derrynaseer bog are intact but the surfaces are relatively dry with few hollows. There is some of the rare Sphagnum imbricatum and Sphagnum fuscum. Modern, mechanized peat cutting has taken place on the edge of Derrynaseeer and indeed it has been scattered through most of the cut-over bogs, particularly northeast of Irvinestown.
Although intact raised bogs are especially valued for conservation, cut-over bogs do have value; the wet edges may give rise to wet woodland and the drier surface to birch woodland. Pools derived by cutting can provide habitats for dragonflies and the cut-over bog as a whole is important for wetland birds; breeding lapwing, snipe and curlew are recorded from cut-over bogs in this LCA.
Heathland is scarce in the LCA and is limited to small patches on the higher land of the northwest and to thin, dry peat left by cutting.
Wetlands and Lakes
Fens and reedbeds are relatively scarce in the LCA being confined to marginal belts around some of the lakes.
The LCA contains examples of mesotrophic, eutrophic and marl lakes;
- Raw Lough is an example of mesotrophic lakes of the "Nymphaea/Fontinalis/Littorella' type - that is, relatively nutrient and base poor, at mid-altitudes and generally in sandstone areas.
- Aghlisk and Galbally Loughs are eutrophic standing waters and of a rare type that displays a Fermanagh/South Tyrone bias; they are relatively un-enriched in comparison with other lowland lake types.
- Parkhill and Maghera Loughs are also eutrophic but are moderately enriched; nevertheless this type has the highest diversity of aquatic macrophytes in eutrophic water bodies.
- Liscreevin Lough belongs to one of the rarest types of lake - marl lake that are most common in the limestone of Fermanagh.
The Ballinamallard River has river water crowfoot, otter and white-clawed crayfish.
It and the Colebrook River (outside this LCA) are part of a cross-border salmon enhancement initiative for the Erne system.
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:
- enhance the biodiversity value of demesne/parkland woodland through control of grazing and felling; by encouraging planting of saplings of the standard trees; by preventing further loss of parkland; by retention of fallen and veteran trees (particularly for bryophytes, ferns, fungi and fauna)
- further study of the history and ecology of demesne and other 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 native broadleaved woodlands. through appropriate grant schemes, rather than the small conifer plantations which are of poor biodiversity and landscape value
- prevent loss of wet woodlands and birch woodland from cut-over bogs - loss from drainage, land-fill
GRASSLAND AND ARABLE
Issue: poor biodiversity of farmland
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 less intensive management of pastures to allow reversion to more species-rich grassland and protect unsown grassland, particularly wet grassland
- maintain and enhance wet grassland by restricting field or arterial drainage
HEATH AND BOGS
Issue: raised bogs are of national and international importance and this LCA contains
good examples of intact lowland bog
Actions:
- maintain the integrity of existing lowland raised bogs by for example, preventing infilling, fly-tipping, fires, new drainage and new peat cutting
- consider restoration of raised bog habitats through appropriate water level management, removal of individual colonising trees and phasing out peat cutting
- prevent new forest planting on raised bog
WETLANDS
Issue: important mesotrophic, eutrophic and marl lakes 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 streams in relation to expansion of rural/urban housing and associated septic tanks/sewage treatment plants
- monitor effects of peat cutting on sediment load and deposition (especially important for spawning and nursery beds of salmonid fish)
