Loughgall Orchard Belt 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
- woodlands account for less than 4% of the land cover compared with about 5.6% for Northern Ireland as a whole. It is mainly of two types, demesnes woodland and wet woodland
- wet woodland occupies former cut-over bog and is probably the majority of the woodland
- grassland cover of the LCA is similar to the c.71% for Northern Ireland as a whole; of this more than four-fifths is improved pasture of generally low biodiversity
- many scattered small pockets of wet grassland, and acid grassland on cut-over bog
- lowland raised bog is extensive across the north of the LCA, extends southward in the Blackwater valley and in the flatlands west of Portadown. Almost all has been cut-over in the past, much has been colonised by birch woodland and little intact bog remains
- fens are generally small and form a mosaic with reedbeds around loughs
- rivers with Priority Species and salmon
Woodlands
Woodlands account for less than 4% of the land cover compared with about 5.6% for Northern Ireland as a whole. It is mainly of two types, demesnes woodland and wet woodland - much of the latter occupies former cut-over bog and is probably the majority of the woodland.
Demesne woodland (lowland woodland pasture and parkland) includes that at The Argory (a National Trust property). The planted woodlands are mainly of beech and oak with an understorey of predominantly alien species including rhododendron, cherry laurel, and snowberry. These have prevented the development of the ground flora throughout much of the property. However, there is a rich epiphytic lichen community and several rare moths have been reported, including the oak-associated lunar marble brown and brindled green.
The estate woodland at Loughgall is now in the charge of the Forest Service and most is modern planting. Sections of the woodland are mainly coniferous with Scots pine and Norway spruce, but elsewhere the compartments are extremely diverse and contain oak, Norway spruce, sycamore, ash, beech and walnut amongst several others. Some of the older planting survives including the lime avenue and the yew walk that reportedly has trees more than 300 years old. Drumart Wood is mature estate woodland to the southwest of Loughgall. Tree species include sycamore, horse chestnut, ash, beech, larch and other conifers. Hazel is extensive in areas of the understorey where cherry laurel is also widespread and elder is occasional.
Although most of the planting at Loughgall is modern it occupies sites that were in woodland in the 1830s. The Argory (then Derrycaw House), Summer Island, Dartry Lodge, Benburb, Ardress and Crow Hill were also planted by the 1830s. These woodland sites are therefore at least 'long-established' and offer opportunities for many species to have colonised and, especially where the canopy is still broadleaved and the understorey not too dense, diversity of the herb layer, mosses and lichens to have developed.
Wet woodland is widespread, the majority developed on cut-over bogs. However, it is often wet only around the margins and other sites where the cutting was deeper. In such sites willow and alder may dominate whereas on the drier peat left by cutting, birch dominates. Argory Wood is a typical example; semi-natural birch scrub grows on cut-over bog and goat willows fringe the site. Scot's pine and cherry laurel are widely present on the drier surface and the ground cover comprises of purple moor grass and bramble. Kilmore Wood is a similar area of natural birch and willow scrub. The latter forms wet carr woodland with a herb layer of creeping bent and reed canary grass. Bramble and elder provide an understorey in the drier areas. Similar carr woodland can be observed at Roscoy Wood and at Millers Bridge.
Carganamuck Wood is one of the few woodlands in the LCA that is neither of demesne origin nor wet woodland (although some willow scrub occurs). Although extensively cleared in the 1940s, leaving only the core intact, it has regenerated. The canopy composition and structure varies through the wood, but generally it is representative of lowland, oceanic base-rich woodland similar to woods in Fermanagh. The mature canopy of the central core is formed by hybrid oak (sessile oak x pedunculate oak) with wild cherry, downy birch, ash, goat willow and a few wych elm. The understorey is predominantly hazel, hawthorn and holly.
Grassland and Arable
Grassland cover of the LCA is similar to the c.71% for Northern Ireland as a whole. Of this, more than four-fifths is improved pasture. This generally has 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 about 16% of the land cover in this LCA, which is much higher than for Northern Ireland as a whole (c.6%), but includes the area of apple orchard. Arable fields are scattered throughout the LCA, but less frequent in the north where there are extensive cut-over bogs, and generally on the drumlin slopes. The orchards are in the southwest two-thirds of the LCA, avoiding the flat lands of the north and those towards Portadown; they are also on the drumlin slopes.
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 are generally well managed near to roads, but tend to become overgrown and gappy away from them, especially where farming is less intensive. Hedgerow trees are commonly ash.
Less intensively managed grasslands are located generally in the wetter hollows between the drumlins and on flat land alongside streams. In some places these areas have been partially reclaimed from cut-over bogs. In the north, where cut-over bog is extensive acid grassland can be found where trees have not colonised. These acid grasslands may be dominated by purple moor grass and, because of the uneven depth of peat left by cutting, there can be an intermix of bog species with common heather and hare's-tail cotton sedge on dry peat banks, but even bog mosses where conditions are wetter.
However, not all damp areas were formerly under bog. Where drumlins level out at both the top and bottom of slopes, the heavy clay soils become increasingly wetter and water logged (surface water gleyed soils). This produces a transition to a rank grass and rushy acidic grassland that includes purple moor grass, soft rush and compact rush.
There are also some traditionally managed hay meadows (lowland meadows) as at Carganamuck where the hay meadow is covered by a sedge rich, wet grassland community, dominated by common sedge and creeping brown sedge over a calcicole moss carpet formed by Calliergon species. The herbaceous composition predominantly consists of marsh bedstraw, meadowsweet and ragged robin. Traditionally managed hay meadows are a scarce and declining habitat in the UK and although Northern Ireland has a significant proportion of the UK examples, they are still relatively rare especially in the east.
On the drumlin slopes, as for most of the LCA, grassland is generally improved pasture, but there are some fields that are unimproved. A small area of unimproved acid grassland occurs near Carganamuck Wood on steeper slopes to the south of the wood. This has a low sedge sward, dominated by carnation sedge, with abundant common yellow sedge and occasionally flea sedge. Grasses such as sweet vernal grass, red fescue and brown bent also occur in abundance, while associated herbs include knapweed, bird's-foot trefoil, devil's-bit scabious, tormentil, sneezewort and slender St. John's wort.
Despite the frequency of wet grasslands and cut-over bogs, the number of breeding waders recorded in the LCA is low, perhaps because, apart from in the north where cut-over bog is extensive but is treed, the inter-drumlin sites are small. Only a few breeding lapwing and snipe are recorded. In the farmland generally, bird Priority Species recorded include song thrush, spotted flycatcher, tree sparrow, skylark, reed bunting and linnet.
Heaths and Bogs
Lowland raised bog is extensive across the north of the LCA, extends southward in the Blackwater valley and in the flatlands west of Portadown. Almost all has been cut-over in the past, much has been colonised by birch woodland (see above) and little intact bog remains. Nevertheless, cut-over bogs can be of significance to biodiversity because the variation in peat depth and wetness that has been left produces several micro-habitats that suit a range of species. At the extensive cut-over Selshion Bog there is the rare Irish damsel fly and also rare ground beetles.
The bog at The Argory is the best example of a remaining raised bog. Although it has been cut-over in the past and there are old drains, there are elements of typical bog vegetation - common heather, cotton sedges, white-beaked sedge, bog asphodel and bog mosses. The less typical cranberry also occurs here. The past cutting and draining has led to some drying of the surface and consequent invasion by pine, birch and rhododendron from surrounding woodland, but recent clearance of the High Moss has been very successful.
In the north, around Derryveen - Courtney Islands and Derryore, there is recent mechanical extraction of peat. There is no heathland in the LCA.
Wetlands and Lakes
Fens are generally small and form a mosaic with reedbeds around loughs, as for example at Lough Gall. The most extensive complex is at Edenderry Lough where there are reedbeds, swamp and tall herb fen.
The lake at Ballintaggart Quarry is an example of mesotrophic lakes, but is species poor. Most other lakes in the LCA have been affected to some extent by nutrient enrichment from surrounding land and are of little biodiversity interest.
The River Blackwater, Callan River and Upper Bann all have river water-crowfoot; the Blackwater also has the white-clawed crayfish and is a salmon river (also trout and dollaghan). The otter is widespread.
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: relatively low woodland cover of variable biodiversity value, in demesnes and wet woodland
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 replacing (upon harvest) conifer plantations with native broadleaves; 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 planting of native broadleaved plantations, through appropriate grant schemes, rather than small conifer plantations which are of poor biodiversity and landscape value
- protect wet woodland, including on cut-over bog, from loss due to drainage, peat extraction and dumping
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 areas of unsown grassland
- maintain and enhance wet grassland by restricting field or arterial drainage
- leave stubble over winter, rather than autumn ploughing, to increase food resources for farmland birds; spring sown cereals are beneficial to breeding farmland birds.
HEATH AND BOGS
Issue: Northern Ireland has a large proportion of the UK's lowland raised bogs, which are also a European priority habitat - they are of national and international importance
Actions:
- maintain the integrity of existing lowland raised bogs, even though cut-over, by for example, preventing infilling, fly-tipping, fires, new drainage and new peat cutting
- consider restoration of some raised bog habitats through appropriate water level management, tree removal (individual trees) and phasing out peat cutting
- prevent new forest planting on raised bog
WETLANDS
Issue: fens in Northern Ireland are a large proportion of the UK resource
Actions:
- protect fens against loss by drainage and infill, which includes use as official refuse tips as well as sites in which to deposit building rubble and fly-tipping.
- leakage of fertilizers and slurry from surrounding agricultural land should be prevented as this increases the nutrient levels and affects species composition.
Issue: nutrient enrichment of lakes and need to protect rivers important for Priority Species and salmon.
Actions:
- protect water quality of lakes and rivers through nutrient management, 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
- continued monitoring of streams below industrial plants
- monitor streams in relation to expansion of rural/urban housing and associated septic tanks/sewage treatment plantmonitor streams and rivers in relation to sediment load and deposition from peat cutting as this affects spawning and nursery beds of fish as well as acidity
