Lower Bann Valley 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
- a predominantly flat area extending from the northern shores of Lough Neagh that includes much of the Lower Bann and its tributary, the Clady river
- contains an extensive area of diatomite deposits especially around Lough Beg - Toome Bridge
- has one of the major concentrations of lowland raised bogs in Northern Ireland
- low drumlins form islands within some of the raised bogs and within the pasture dominated floodplain
- wetlands of international importance for biodiversity (Lough Beg and Lough Neagh) occur in the south of the LCA
Woodlands
Woodlands occupy around 4% of the LCA and are comprised of several types.
Demesne woodlands (NI Priority Habitat: Lowland woodland pasture and parkland) are restricted to two main locations in the south of the LCA, the adjacent Moyola Park and Fair View, and Ballyscullion House. Both have fine stands of mature trees in avenues, parkland clumps and boundary plantations. Exotic trees, including conifers are scattered through the woodlands, but ash, sycamore, oak and beech are common; beech woodland is extensive in Moyola Park. Although the understorey and herb layers are poorly developed in beech woodland, an understorey of hazel, hawthorn and holly can be found in other woods. These may also have a herb layer - some species of which may be indicative of ancient woodland.
Hazel woodlands are found in the LCA, some showing evidence of coppicing as at Creighton's Wood and Hollyhill Wood; at the latter site there are several distinct compartments, a feature of wood management that is not common in Northern Ireland.
Oak woodlands are rare in the LCA; a small patch occurs in Creighton's Wood which is managed by the Ulster Wildlife Trust. In contrast, birch woodland is common and generally associated with cut-over bogs and the cut-over margins that surround remaining uncut lowland bogs. Where the cut-over areas are wetter and less acidic, wet woodland of willows and alder is developed. Woodlands on cut-over peat make a significant contribution to the total woodland area in the LCA and need to be retained (see Lowland Raised Bogs below).
Coniferous Forest, dominated by Sitka spruce, Norway spruce and larch is common in the LCA and much of it is planted on cut-over raised bog (see below). Where forest occupies mineral soils, some deciduous trees, including oaks, are occasional and there are indications that some sites may be ancient woodland sites. Ancient woodland sites are, according to present knowledge, rare in Northern Ireland and the Forest Service has initiated studies and restoration programmes for some of its plantations in this LCA that occur on ancient woodland sites.
Grassland and Arable
Improved grasslands occupy about 58% of the LCA and arable about 10%. Both are widely scattered throughout, with arable showing a preference for the low drumlins and better drained soils rather than for the alluvium of the river floodplains. Improved grasslands have little biodiversity and in this LCA hedgerows are often poorly developed. Instead, the pasture field boundaries in the low-lying lands are often ditches. Areas of abandoned or rough pasture are scattered through the LCA, sometimes associated with damper areas around cut-over bog or regressing from pastures developed over reclaimed former bog. Such areas may have a higher biodiversity than the sown and maintained improved pastures. In this LCA, as in much of Northern Ireland, the arable is often rotational with sown pastures rather than repeated cropping of cereals. Managing hedgerows may achieve an increase in biodiversity more easily.
Heaths and Bogs
This LCA has one of the major concentrations of Lowland Raised Bogs in Northern Ireland and contains some of the largest areas of uncut lowland raised bog; a few of the bogs have been designated for their national and international importance, including Wolf Island Bog ASSI and cSAC (also known as Fallahogy Bog) and Dead Island Bog ASSI. Structural features are evident - the domed outline, pools and hummocks, Sphagnum lawns - and there are also rare plant species, including nationally rare Sphagnum (bog-moss) species. In common with most lowland raised bogs in Northern Ireland, the lagg and rand areas of these bogs have been lost through past cutting and have been replaced by a mosaic of habitats including wet acid grasslands, carr and birch woodland. Despite past cutting, the remaining areas of uncut peat are deep and have provided sites for research into the climatic history of Northern Ireland.
Threats to these large intact bogs include continued peat cutting, both by hand and by compact harvester, so that the uncut surface is being nibbled away. In addition, the cutting can lead to drying of the edge of the uncut surface with consequent tearing and slumping of the peat above the cut face.
Fires have spread across some of these bogs in the past, with consequent loss of plant species. A much reduced plant diversity continues for a long period before recovery. It is important that fires in adjacent areas outside the protected area, are carefully managed.
Forest plantations on lowland raised bogs are common in the LCA. In most instances the planting has been on formerly cut-over bogs, especially those alongside the Lower Bann. However, at Moneystaghan Bog, one of the largest lowland raised bogs in Northern Ireland, forest planting has considerably reduced the area of the extensive uncut dome. Current Forest Service policy has a presumption against new planting of ombrogenous bog and it is important that this policy continues to be applied to both the public and private forest sectors. There also needs to be consideration of a future management policy for the maturing forests. This could include the effects on the water table of adjacent uncut areas, as at Moneystaghan, and whether there should be replanting following felling of trees on the former cut-over bogs.
Mechanised cutting of peat for the horticultural market is also a feature in this LCA. Whilst it is unlikely that further bogs will be exploited, and any such plans should be resisted, there is a need to consider the management of these bogs once the supply of extractable peat is exhausted. Reclamation for agriculture or forestry may be alternatives, but blocking of drains and then leaving the areas to develop should also be considered.
Cut-over bogs are common in the LCA; whereas some have been reclaimed for agriculture, most have been colonised by trees and form an important constituent of the woodland cover. This woodland should be retained; fly-tipping should be prevented and they should not be used as land-fill sites.
Wetlands and Lakes
There are many areas of valuable wetland habitat located throughout this LCA that are important for waders such as lapwing, curlew and snipe, e.g. Tyranee and Eden Hill. Of particular importance is the west shore of Lough Beg. Here, there is a large expanse of wet grassland and marsh (NI Priority Habitat; Coastal and floodplain grazing marsh) that is flooded each winter and which has never been agriculturally improved. The Lough Beg ASSI/NNR, (also part of the proposed Lough Neagh SPA and Ramsar sites), comprises 300 acres of this habitat and in spring and autumn is an important site for migrating birds and for breeding waders. Winter floods bring hundreds of wildfowl to feed on the inundated land, indeed the concentrations of wintering wildfowl gives the site international importance. The site also includes many rare plants including pennyroyal, and the Irish ladies' tresses.
Lough Neagh (NI Priority Habitat: Eutrophic Standing Waters) occupies the south-eastern tip of the LCA from Traad Point to Toome Bridge. It is an ASSI, proposed SPA and forms part of a Ramsar listed site. There is a wide variety of habitats including submerged and floating aquatic vegetation (confined to sheltered bays and inlets), swamp, fen and fragmented wet woodland. In common with Lough Beg, it is important nationally and internationally for its populations of wetland birds. In this LCA sand and gravel extraction has taken place along the shoreline of Lough Neagh, to leave small lakes as at Moyola Water. Gravel workings, once abandoned, have potential if left undisturbed to become important conservation sites.
The major threat to Lough Neagh has come from nutrient enrichment, largely as a result of the application of slurry and fertilizers to agricultural land and discharge of sewage effluent; algal blooms and loss of oxygen have resulted in the past, with consequent deleterious effects on fish life. This may be one cause of the decline of the pollan in Lough Neagh. The Lower Bann flows through the LCA, with many tributaries joining, including the Inverroe Water, the Culmore River and the Clady River. The Moyola River in the south of the LCA drains into Lough Neagh. All of these rivers have important populations of Atlantic salmon and brown 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: woodland cover is of variable biodiversity value and includes significant areas of the NI Priority Habitats Lowland Woodland Pasture and Parkland and wet woodland.
Actions:
- enhance the biodiversity value of demesne/parkland and wet woodlands through limiting felling and grazing; by preventing loss of demesne/parkland and wet woodlands; by retention of fallen and veteran trees (particularly for bryophytes, ferns, fungi and fauna); also encourage control of grazing in broadleaved woodlands to foster herb layer and regeneration and if necessary, encourage replanting of canopy species
- further study of the history and ecology of beech and other woodlands within the LCA, particularly any ancient and long-established, as a key to future management; monitor sites
- management plans for demesne woodlands should be directed towards their survival - through natural regrowth or through tree planting (in a manner that supports their contribution to the landscape and to biodiversity); ensure that hazel scrub is not cleared and consider the introduction of rotation coppicing that might result in a more diverse ground flora, particularly of spring flowering plants
- ensure conservation of wet woodlands of willow and alder - that they are not lost through drainage, reclamation, landfill or dumping/tipping
GRASSLAND AND ARABLE
Issue: poor biodiversity of improved pastures and poorly developed hedgerows
Actions:
- maintain and improve field boundaries, especially hedgerows where they occur through adoption of correct cutting cycles; hedge laying and replanting where necessary; leave saplings uncut to develop into hedgerow trees; avoidance of spraying with fertilisers, slurry, herbicides; provision of wildlife strips and conservation headlands around fields; and limitation of field amalgamation
- encourage (through participation in Environmental Schemes adoption/continuance of less intensive management of pastures to allow reversion to/continuance of more species-rich grassland and protect unsown areas of grassland including dry, calcareous grassland
- maintain and enhance damp grassland around cut-over bogs or over reclaimed former bogs, by, where possible, 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 farmland birds
HEATHS AND BOGS
Issue: this LCA contains some of the largest uncut areas of the NI Priority Habitat Lowland Raised Bogs; a number of these have been designated as for their national and international importance
Actions:
- maintain the integrity of existing intact lowland raised bogs e.g. Wolf Island ASSI and cSAC, by preventing infilling, fly-tipping, fires, new drainage and peat cutting by hand or compact harvester- applies particularly to intact bogs but cut-over bogs can provide important habitats for birds and invertebrates; it is important that fires in adjacent areas outside the protected areas are carefully managed
- consider restoration of bog habitats through appropriate water level management, removal of individual colonising trees and phasing out peat cutting - applies particularly to areas of recent mechanical cutting; consider blocking of drains on bogs which have exhausted the extractable supply of peat and then leaving these areas to develop
- prevent new forest planting on blanket bog; ensure that the current Forestry Service presumption against new planting of ombrogenous bog be applied to both public and private forest sectors
WETLANDS AND LAKES
Issue: the NI Priority Habitat Coastal and floodplain grazing march, represented at Lough Beg ASSI/NNR, is important for waders such as NI Priority Species curlew
Actions:
- ensure that extensive areas of wet grassland and marsh are retained, including the area outside the nature reserve, by preventing field and arterial drainage
- maintain and improve grassland through adoption of correct cutting and grazing regimes; this should also minimise disturbance to migrating birds and breeding waders
Issue: the NI Priority Habitat Eutrophic Standing Waters, represented at Lough Neagh, is threatened by nutrient enrichment
Actions:
- protect the water quality of rivers through nutrient management and by reducing suspended sediments; prevent the release of particles released through peat cutting or forestry operations; install sediment traps at large extraction sites
- promote and encourage adoption of Countryside Management guidelines so that rivers are not polluted by releases from silage effluent, herbicides, pesticides, fertilisers or sheep dip
- monitor the River Bann and its tributaries in relation to peat cutting (sediment load and deposition) - important for the populations of Atlantic salmon and brown salmon that nursery and spawning beds are clear; monitor rivers in relation to expansion of rural/urban housing and associated septic tanks/sewage treatment plants; monitor rivers in relation to forestry and other operations upstream which may be important
