Carrickmore Hills Biodiversity Profile

Last updated: 20 November 2006

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

Woodlands are less than 2% of the land cover, a low percentage even for Northern Ireland (c.5.6%). There is no extensive State Forest apart from the western half of Drum Manor and coniferous woodlands are generally small and some recently planted.

Drum Manor occupies the former Oaklands demesne so that some of the original planting (pre-dating the 1830's) remains, but most is mixed planting in a complex arrangement of compartments and forest plots; Norway spruce, Japanese larch, beech and oak are the most common species with some pure compartments of Sitka and Norway spruce.

Demesne planting accounts for much of the woodland in the LCA; in addition to that at Drum Manor, estate woodlands (lowland woodland pasture and parkland) are located at Wellbrook, Drumshambo (Corkhill), Termon (Athenree) and Lough Macrory Lodge. All of these were present by 1833 and much of today's woodland is at least 'long-established'; some small patches of semi-natural woodland were incorporated in these estates so that there may be elements of 'ancient woodlands' that could contain plants of the herb layer, mosses and lichens restricted to such woodlands. Beech is often dominant and oak is a common constituent, as is Scots pine, sycamore and birch; alder and willow are common in wetter parts.

Grassland and Arable

Grassland is c.76% of the land cover of the LCA, slightly higher than for Northern Ireland as a whole (c.71%); about two-thirds of the grassland is improved pasture. These have generally low biodiversity as a result of relatively intensive management, but the degree of improvement varies. 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, but less intensive management may result in less reduction of diversity. Arable land is insignificant in this LCA.

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 hedges are confined to the lower land with improved pastures, elsewhere they become scrubby, with much gorse, and reinforced by fence-and-wire. Even in the lower lands hedges are poorly maintained and gappy; where hedgerow trees are present they are mainly ash.

Rough and acid grasslands are widespread throughout the LCA; in the east they tend to be located in damp, inter-drumlin hollows and where the river valleys widen; these sites are either small cut-over bogs or organic alluvium soils. The fields tend to have abundant clumps of rushes with grazed grasses between, or are rush dominated, with plants such as meadow sweet also indicating the wet conditions. Further west, with an increase in altitude and widespread peat and peaty soils, acid grasslands become more common, but they are often difficult to distinguish because of the intricate pattern of the land cover; cut-over bog and pastures that are reverting, tend to merge into better-drained rocky slopes and areas underlain by gravels and sands that have species of drier heath.

The intricate pattern of land cover types and habitats has enabled many bird Priority Species to find suitable habitats; thus curlew, reed bunting, skylark, spotted flycatcher, song thrush, bullfinch, yellowhammer and linnet, have been recorded in addition to breeding lapwing and redshank. Irish hare also finds refuge in the less intensively managed farmland.

Heaths and Bogs

Upland heathland, a declining habitat in the UK, is widespread in the western half of the LCA, partly as a result of steeper rocky slopes to some of the hills, where gorse, common heather and bell heather may be found, partly because some cut-over peatland has become dominated by common heather, and partly because of the underlying parent materials which have led to thin peat and peaty soils - The Murrins NNR is an example. Here the peaty podsols support rich heath vegetation dominated by bell heather that is home to the red grouse. The biodiversity of the site is increased by many small lakes that have mallard, teal and occasional nesting feral greylag geese (see Wetlands below).

Although small bogs (lowland raised bog) may be found between drumlins in the northeast of the LCA, they are all cut-over and several have been colonised by trees. Most of the peat bog in the LCA may be classed as blanket bog, but classification is difficult because many of the areas of deeper peat that remain after cutting and reclamation to farmland, have the appearance of raised bogs. Classification is also difficult because of the pattern of land cover - heath, acid grassland and bog are all intricately mixed. A further difficulty is the extent of modern peat extraction; almost all the peat bogs, whether cut-over or intact, have been affected. For example, around Cregganconroe there were three relatively large areas of intact bog, about 88ha in all, but from the early 1980s there has been extensive machine cutting and the intact area has been considerably reduced. Similarly, much of a large (57ha) intact bog east of Lough Cam has been lost. In recent years the extent of machine extraction in this LCA has reduced and the process of recovery has begun.

On some of these relatively large intact bogs pool and hummock complexes have been mapped, adding to the habitat and species diversity. Species of bog mosses (Sphagnum) and other bog plants, are adapted to different water-table heights; some are located in pools, such as bog bean and Sphagnum cuspidatum, whereas others are found where the water-table is around the bog surface, including S. papillosum, common cotton sedge, sundews, bog asphodel and cross-leaved heath, and S. acutifolia, hare's-tail cotton sedge, deer sedge and common heather are on the drier hummocks.

In Europe, blanket bogs are confined to the northwest margins of the continent so that the blanket bogs of Ireland and of Northern Ireland are of international importance. However, over the centuries they have been reduced in extent through cutting for fuel, afforestation and reclamation to farmland. The remaining examples (including those in this LCA), particularly of intact bog with micro-topographical features and micro-habitats such as pools and hummocks, are of increased local, national and international significance. The bogs, together with the intermixed heath and acid grasslands, also provide habitats for breeding waders - lapwing, curlew and redshank have all been recorded from bogs in the LCA - and for other breeding and over-wintering birds. They also offer micro-habitats for many insects, especially groups such as water-beetles and dragonflies.

Wetlands and Lakes

There are no significant areas of fen and reedbeds are not extensive (Loughanillan, Loughnapreast and Garadrum B). Eighteen lakes were surveyed by the Northern Ireland Lake Survey, the majority of which were classified as peaty, low pH lakes with a high degree of peat stain, and are generally unproductive and of low priority. Lough Macrory, Loughnapeast, Lough Mallon, Evishanoran B and Garadrum B are mesotrophic lakes, the latter being of low priority. Mesotrophic lakes, that is, characterised by having a middle level of nutrients between nutrient poor (oligotrophic) and nutrient rich (eutrophic), 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.

The Upper Ballinderry River has been recognised as one of the most important rivers in Northern Ireland for rare aquatic species (Upper Ballinderry River SAC, Upper Ballinderry River ASSI). It is of particular importance for the freshwater pearl mussel as it is one of the few rivers in Northern Ireland that still retains a significant and viable population of this rare shellfish. In addition, the river supports a good range of native fish species, including brook lamprey and brown trout. Otter and kingfishers are present along the length of the river. The middle reaches also have stream water-crowfoot. The otter is recorded in many of the rivers and lakes.

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: raised bogs/blanket bogs are of national and international importance

Actions:

WETLANDS

Issue: important mesotrophic lakes and rivers with Priority Species

Actions:

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