Glenelly Valley Biodiversity Profile

Last updated: 9 February 2010

In the following account 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

Woodlands account for just under 2% of the land cover, low even in relation to the percentage for Northern Ireland as a whole (c. 5.6%). The largest woodland in the LCA is part of Goles Forest, a coniferous forest dominated by Sitka spruce and of low biodiversity interest.

Throughout the LCA the commonest form of woodland is the small (0.5 to 1 ha) coniferous plantation; these are widely scattered across the slopes and alongside streams and have little biodiversity value. They are commonly pure stands of Sitka spruce although there are some of larch and a few of mixed conifers. Mixed broadleaved and conifer woodlands also occur either where the conifer plantation has included some native trees and scrub (such as hazel, ash, rowan, birch and willow), or where native woodland has been modified by the addition of a few individual conifers. Two of the largest woodlands, excluding Goles Forest, are mixed broadleaved-conifer; The Eagle's Nest is a planted woodland, although present by 1830, consisting of sycamore, beech and ash with Scots pine and silver fir. More recent larch and Sitka spruce have been planted at the edge. The woodland is rich in epiphytic mosses and lichens and has a species-rich herb layer despite some grazing and generally poor management. This species diversity may result from the steep slopes of the wood and its age (i.e. 'long-established' - present by 1830). Alongside the Glenelly, below Barnes Gap a predominantly birch - hazel - oak woodland has larch intermixed; here too there are abundant epiphytes, but the herb layer is grass dominated as a result of grazing.

Broadleaved woodland is limited to small patches alongside steeply incised streams and abandoned meander scars cut in the glacial deposits alongside the Glenelly river. One of these woodlands lies next to the mixed woodland below the Barnes Gap; it is predominantly oak and hazel and although not shown on the 1830 map and despite quite heavy grazing, it has a very diverse herb layer and is rich in epiphytes. Elsewhere, hazel woodland/scrub, sometimes with ash or oak, and birch - willow - alder scrub comprise the broadleaved patches.

Although there are no large broadleaved woodlands, the scattered patches are important to the biodiversity of the LCA, especially as it is dominated by improved grassland and acid grasslands of low biodiversity.

Grassland and Arable

Grassland covers approximately 86% of the LCA; this is high in comparison with Northern Ireland as a whole (c. 71%). In most LCAs improved pastures dominate, but here almost two-thirds of the grassland is in rough or acid grassland. Improved pastures are confined to the valley floor and the lower slopes, gradually broadening westward.

Improved pastures have generally low biodiversity as a result of relatively intensive management. Some pastures are sown grasslands dominated by ryegrass and few other species - low biodiversity is in-built, but others 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 (includes grass re-seeding) is insignificant.

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 predominantly hawthorn hedgerows dominate in the improved pastures of the valley and are frequently treed; they are, however, often gappy and reinforced by wire. Nevertheless, many of the hedgerows in this LCA are a refuge for species, notably for spring flowering plants such as primrose. Upslope of the improved pastures, field boundaries deteriorate; hedges become mere lines of individual shrubs along banks and stone walls.

Upslope of the current improved pastures, there is a zone where fields have been abandoned; these fields are dominated by soft rush where the soils are wet, but on drier sites, possibly because of steeper slopes or differences in the soil parent materials, more heathland grasses may be found; in a few areas with well-drained glacial deposits former lazy-beds are occupied by bracken. This zone of abandoned land is irregular, partly depending on slope and parent material, but also on the history of land use; additionally, some parts have been reclaimed in recent times and are in productive, sown pastures.

Above this marginal zone the hill slopes are covered by cut-over peatland; because of the variation in depth of peat that has been left there is a variation in the vegetation cover. Deeper islands of cut-over peat may be dominated by heather or have several of the bog species, whereas large parts of the cut-over bog may be dominated by coarse grasses such as purple moor grass or mat grass, with heath rush, and tormentil. Flushes with greater species diversity also occur.

Heaths and Bogs

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.

picture of bog asphodelIn this LCA there is a limited amount of intact bog that is restricted to parts of the flat ridge tops and spurs on the northern and southern borders, but even this small amount has come under attack in recent times Examples include Mullaghsallagh, where intact bog has been degraded by prolonged over-grazing with a gradual, but notable reduction in the dwarf shrub and bog moss cover. At Oughtvabeg, the previously intact surface is crossed by an extensive drainage network. Such drainage reduces the cover of bog mosses, asphodel and other plants of the wetter bog surface, and increases the cover of heather and purple moor grass. There has also been recent mechanical peat extraction although most of that has occurred on the former cut-over bog.

There is some upland heathland, dominated by common heather, as on the southeast slopes of Oughtvabeg, but generally the heather dominated areas are on peat that is more than 50cm in depth. These areas are therefore blanket peat rather than heathland. Red grouse is recorded from these heather dominated areas in the LCA.

Wetlands and Lakes

There are no important lakes, fens or reedbeds in the LCA. The otter has been recorded in the Glenelly River, which is important also for salmon and trout.

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:

GRASSLAND AND ARABLE

Issue: poor biodiversity of farmland

Actions:

HEATH AND BOGS

Issue: loss of upland heathland and decline in its biodiversity

Actions:

Issue: blanket bogs are of national and international importance

Actions:

WETLANDS

Issue: rivers generally of good water quality and important for salmon and trout

Actions:

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