Moyola Floodplain 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
- most of the LCA is a broad floodplain of the Moyola river
- large lowland raised bogs dominate the centre
- woodlands are limited to broadleaf plantation in the higher land of the northeast; woodland on cut-over bog, especially around the large, central raised bogs, makes an important contribution to the total woodland area
- elsewhere pasture dominates and includes poorly drained wet pastures
- hedgerows form the dominant field boundaries
Woodlands
Woodlands occupy less than 5% of the LCA and comprise limited areas of plantation woodland such as around Knockloghrim, and woodland established on cut-over bog. The former are largely comprised of non-native species such as sycamore and beech. Ground flora is generally poor, especially beneath the heavy canopy of beech. Nevertheless, Northern Ireland is so poorly wooded that these woods should be retained both for biodiversity and for their contribution to the landscape.
Woodland established on cut-over bog is a major contribution to the limited woodland area. It occurs either on the cut-over edges of the larger bogs such as Ballynahone and Curran bogs (see lowland raised bogs below) or may cover smaller bogs that have been completely cut-over. Where the remaining peat is relatively dry, birch is the dominant tree, but may be accompanied by rowan and ash, especially if there is little peat remaining. On wetter locations alder and willow dominate. (NI Priority Habitat: Wet Woodlands).
Grassland and Arable
Improved and managed grassland occupies around 70% of the LCA and arable about 10%; grasslands dominate on the low- lying alluvial floodplains whereas the arable fields are mainly on the slightly elevated land with better drained soils. Improved grasslands generally have poor biodiversity, but there are areas of poorer quality grasslands with higher biodiversity intermixed, especially alongside remaining bogs and cut-over bogs. For example, damp grasslands between Ballynahone Bog and Magherafelt, around Ballinderry and Oak Island to the south of Curran Bog, and around Dromore are important areas for breeding waders such as lapwing, curlew, redshank and snipe.
Hedgerows form the majority of the field boundaries. In the lower lying areas, particularly near to the central raised bogs, these are often dominated by willow whereas hawthorn hedges are dominant elsewhere. Most of the hedges in the LCA are poorly managed; many have become gappy and overgrown. Hedgerow trees of ash and oak are also characteristic of the LCA, but partly because of poor hedgerow management, over-mature trees are not being replaced. In addition to their landscape value, hedgerows are important for butterflies, moths, farmland birds and plants - especially in the poorer pasture areas where herbicides and pesticides are not used extensively.
Heaths and Bogs
This LCA has relatively few raised bogs, but those occurring include some of the most important remaining lowland raised bogs in Northern Ireland (Ballynahone Bog ASSI/NNR and Curran Bog ASSI). They have extensive areas of uncut bog with good examples of the associated structural features, such as a domed profile and bog pools and hummocks, as well as some rare plant species, including nationally rare bog mosses. In common with most raised bogs in Northern Ireland, the marginal lagg has been cut-away in the past, but has been replaced with a diversity of habitats and species. Small patches of fen and acid grassland are found, but much of the former cut-away is covered in woodland of birch, alder and willow - the tree species found depends on the wetness of the remaining peat. The bogs are also an important habitat for breeding birds such as curlew (a NI Priority Species) and snipe and wintering species, including birds of prey such as hen harrier and merlin. The marsh fritillary butterfly and the large heath butterfly are also notable on these bogs. The international importance of these sites is recognised in the RAMSAR and cSAC status of Ballynahone.
A limited amount of hand-cutting still occurs and the two largest bogs in the LCA have been threatened by mechanised cutting in the past. Remedial action, plugging former drains, has begun to return the large uncut area at Ballynahone to its former condition. Although cut-over areas have lost many of the features and species associated with lowland raised bogs, they often have areas of good heather dominated cover as well as a diversity of developing communities and habitats.
Wetlands and Lakes
There are no extensive areas of open water in the LCA. The Moyola River flows west to east through the centre of the LCA and is fed by the Grange Water, Back Burn and Milltown Burn. All flow through extensive areas of improved pasture so that there are potential threats from fertilizer and slurry pollution. Threats to fish from particulate pollution have receded with the curtailment of plans for commercial peat extraction. Otters have been recorded on the Back Burn and the Moyola; the latter also has river water-crowfoot.
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. Comprises plantation woodlands and woodland established on cut-over bog, but includes the NI Priority Habitat: Wet Woodlands
Actions:
- enhance the biodiversity value of broadleaved woodlands (including non-native) by discouraging felling; by preventing loss of broadleaved woodlands; by retention of fallen and veteran trees (particularly for bryophytes, ferns, fungi and fauna)
- encourage control of grazing in broadleaved woodlands to foster herb layer and regeneration and if necessary, encourage replanting of canopy species
- encourage planting of broadleaved woodlands through appropriate grant schemes rather than the conifer plantations and shelterbelts that are of poor biodiversity and landscape value; ensure that hazel scrub is not cleared
- ensure conservation of wet woodlands - that they are not lost through drainage, reclamation, landfill, building or dumping/tipping
GRASSLAND AND ARABLE
Issue: improved grasslands of poor biodiversity value are intermixed with damp grasslands of higher biodiversity, that provide important areas for breeding waders such as NI Priority Species curlew
Actions:
- 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 by where, possible, restricting field or arterial drainage; care must be taken when clearing and deepening hedgerow ditches to ensure that the water table is not lowered to the extent that adjacent wet woodlands and bogs are affected
- leave any crop stubble over winter, rather than autumn ploughing to increase food resources for farmland birds; spring-sown cereals are beneficial to farmland birds
- 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
HEATHS AND BOGS
Issue: extensive areas of uncut NI Priority Habitat lowland raised bogs are an important habitat for NI Priority Species curlew and marsh fritillary butterfly
Actions:
- maintain the integrity of existing raised bogs by for example, preventing infilling, fly-tipping, fires, new drainage and hand/mechanised peat cutting - applies particularly to intact bogs but cut-over bogs can provide important habitats for birds and invertebrates; where fly-tipping is a problem the offending material should be removed
- consider restoration of raised bog habitats through plugging former drains, appropriate water level management, removal of individual colonising trees and phasing out peat cutting - applies particularly to any areas of recent mechanical cutting; any proposals for arterial and field drainage on land adjacent to these bogs requires careful assessment so that the water table is not lowered to the extent that peat bogs and woodlands are affected
- prevent new forest planting on raised bogs and monitor plant communities
WETLANDS AND LAKES
Issue: rivers in this LCA, which support the NI Priority Species otter and river water-crowfoot, are under threat from water pollution
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 existing good farming practices through adoption of Countryside Management guidelines, so that rivers are not polluted by releases from silage effluent, herbicides, pesticides, fertilisers or sheep dip
- monitor streams in relation to peat cutting (sediment load and deposition) - important for salmon that nursery and spawning beds are clea
- rrecognise that monitoring of streams in relation to forestry and other operations upstream may be important
