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
Woodlands cover about 11% of the LCA; this is almost double the percentage for Northern Ireland as a whole and results from extensive planting of State Forest on the peat covered uplands. These forests are dominated by Sitka spruce with some Norway spruce, lodgepole pine and larch. Small patches of hardwoods are incorporated in a few localised areas. The forests are generally of low biodiversity, lower than the peatland they have replaced.
Muff Glen is a State Forest but located in a steeply sided river valley; although there is some scrub and broadleaves, the majority of the wood is larch, Norway spruce and Scots pine.
In contrast the nearby Derryarkin Glen is semi-natural woodland occurring along both sides of the Castle River. The species composition varies with the ground conditions and the severity of livestock grazing. Near the river species include ash, alder and goat willow, whereas on drier ground the canopy is formed by sessile oak, hazel, downy birch, ash, sycamore and hawthorn with one small area containing European larch (Upland mixed ashwoods/upland oakwood). The understorey is diverse although hazel is dominant. The herb layer in the dry non-grazed areas contains a diverse flora co-dominated by a mixture of bluebell and wood sorrel; in grazed areas there is much bare ground.
Ness Wood ASSI is a semi-natural acid woodland on the flanks of the deep Burntollet Glen. Although clear-felled and planted after the Plantation of Ulster, the steep slopes and natural regeneration have led to continued dominance of native species - oak, birch, rowan and holly, along with ash, hazel, alder, willow and elm. The wood is also notable for its rich bryophyte and epiphytic lichen community, typical of a western upland oakwood. Both Derryarkin Glen and Ness Wood may represent ancient woodland and if so are relatively rare and of major significance to woodland ecology and history in this part of Northern Ireland.
Grassland and ArableGrassland accounts for just over 55% of the land cover and of that less than two-thirds is in improved pastures. These occur on lower land in the west and along the northern border, but there is a transition with altitude from improved pastures, through acid upland grasslands to cut-over bog.
Improved pastures 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.
Extending upslope, the soils become more heavily gleyed and more humic before passing into the blanket peat. As a result of these wet soils, the grasslands often become more rushy, especially in those remnants of former pastures; the remains of stone walls, banks and gappy hedgerows can also be observed. However, much of the upland acid grassland has developed over former peatland; past cutting has left only a shallow depth of peat. The vegetation is often diverse as a result of different depths of peat that have been left, differences in the drainage or in grazing intensity. In parts there may be a moorland appearance to the vegetation with some rather stunted common heather and other bog species, such as cotton sedges, heath bedstraw and abundant mosses. Other parts may be dominated by grasses; these can include mat grass, wavy hair grass or purple moor grass. Although the plant species occurring may be of limited interest to biodiversity, these wet upland grasslands can be habitats for breeding waders - lapwing, curlew and snipe have all been recorded from these habitats in the LCA - and, along with adjacent habitats, for other birds such as skylark, a declining species in the UK especially from lowland farmland.
Arable land accounts for about 4% of the land cover (but this includes grassland re-seeding) and is confined to the lower land of the west where it frequently corresponds with the well-drained brown earths. It is generally of low biodiversity although important for some farmland birds such as the yellowhammer.
Heaths and BogsBlanket bog is extensive across the uplands of this LCA. However, because of modern forestry and some land reclamation, peatland is less widespread than formerly. The vast majority of the remaining blanket bog has been cut-over and only a few small (<30 ha) areas of intact bog survive. Examples include patches on the slopes between Altnahullion Hill and Muldonagh Hill, on the north slopes of Glenconway Hill and at Glasakeeran.
Northern Ireland's blanket bogs are of international importance; blanket bogs in Europe are found only on the northwest seaboard of the continent and Ireland thus has a large proportion of the associated habitats. Intact blanket peat is particularly important because it is rarer and is likely to contain plant species not found elsewhere on bogs. However, the small intact patches in this LCA are under threat from modern peat cutting. In addition to the large-scale commercial extraction that has taken place at Altnahullion, compact harvester cutting (sausage machine) is scattered throughout the blanket peatland. Whilst most of this is on formerly cut areas, it does impinge on some of the intact bog.
There are no lowland raised bogs in the LCA, although in some of the flat floors of upland valleys raised bogs do occur within the general blanket bog; an example is near Slaghtmanus Bridge. This, like the peatland around it, is cut-over and also has modern compact-harvester cutting.
The vegetation of cut-over peatland is varied; not only are thinner areas often in acid grassland (see above) but where of greater depth the drier peat may be dominated by lank heather to form upland heathland. In other sites, the ground beneath abandoned hand cutting faces may have healed so that there is abundant bog moss (Sphagnum) and cotton sedge as well as perhaps open water; the micro-mosaic of habitats allows many insects, particularly water-beetles and dragonflies to flourish.
Upland heath is also found on some slopes of relatively dry, thin peat, but this is uncommon in this LCA; it is also not always clear whether these sites are 'natural' or whether there has been past cutting.
Wetlands and LakesThere are no lakes of significance in the LCA. Although none of the rivers have records of Priority Species, several are tributaries of the Faughan or the Roe and therefore part of the Foyle system. The Foyle system is of international importance for Atlantic salmon and that part of the system in Northern Ireland, including the Faughan and Roe, is the largest salmon and trout fishery in the country.
Key IssuesGeneral actions for UK and NI Priority Habitats and Priority Species are detailed in the Habitat Action Plans and Species Action Plans.
WOODLANDSIssue: low woodland cover of variable biodiversity value
Actions:
Issue: poor biodiversity of farmland
Actions:
Issue: loss of upland heathland and decline in its biodiversity
Actions:
Issue: blanket bogs are of national and international importance, in particular any intact bogs. This LCA has little intact bog and it is under threat from forestry and peat cutting.
Actions:
Issue: important rivers for salmon and trout
Actions: