Burngibbagh and Drumahoe Biodiversity Profile
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 cover only about 1% of the LCA, considerably lower than for Northern Ireland as a whole (c. 5.6%)
- woodland located as small patches in steep-sided tributary valleys, as wet woodland patches, and in estates
- grassland covers c.82% of the LCA, three quarters of which is improved pasture of low biodiversity; the remainder - rush dominated acid grassland - is also of low biodiversity
- small amount of upland heathland, but almost no peatland
- R. Faughan of importance for Atlantic salmon
Woodlands
Woodlands cover only about 1% of the LCA, considerably lower than for Northern Ireland as a whole (c. 5.6%). It occurs as small patches alongside tributaries to the Burngibbagh and Faughan, as for example at Carnafarn where oak, ash and sycamore are frequent, but there is also some beech that may indicate 'landscaping'. The ground conditions are often quite wet but the herb layers are diverse. Elsewhere there are small patches of scrub and wood along the flat floor of the Burngibbah valley and on hillsides where soil drainage is particularly poor; willow and alder are dominant (wet woodland).
Although individual estate woodlands are small, they are locally significant and include a band east of Derry stretching from Ashbrook to Birch Wood, and Dullerton in the south (lowland woodland pasture and parkland). Typical trees of estate woodlands are found, including beech, Scots pine, lime and oak, but there is also birch, and willows and alder in wetter parts. Most of these estate woodlands, and some of the woods alongside the steep tributary valleys, were present by 1830 and indeed many have been traced back to at least the seventeenth century; 'long-established' (at least from 1830) and possibly 'ancient' woodlands (pre-1600) are thought to be rare in Northern Ireland and may contain species not common in more recent woods.
Grassland and Arable
Grassland covers c.82% of the LCA, three quarters of which 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 cover is similar to that for Northern Ireland as a whole (c.6%); although scattered through the LCA, it is more concentrated to the north on better-drained brown earth soils.
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 around regular, square fields, are generally well-managed in the lower parts but thin towards the uplands where the improved pastures merge into acid and heathy grasslands. The northern part, which contains the lower Faughan River, has a more open character, with larger fields and a relatively wide, unenclosed valley floor; there has been some loss of hedgerows through field amalgamation. In the south, on the low ground of the Burngibbagh valley, the hedgerow trees are dense.
Acid grasslands on the upper slopes of the hills are dominated by rushy fields; some have been abandoned and colonised by willow and alder whereas other merge into heather heath. Rush dominated fields are also common on the organic soils of the flat floor of the Burngibbagh valley.
The variety of land cover within the farmland has created habitats for several bird Priority species, including skylark, song thrush, spotted flycatcher and yellowhammer.
Heaths and Bogs
There is only a little blanket bog in the LCA, on the slopes of Curryfree, but this is cut-over; elsewhere the upland slopes are only of thin peat and generally covered by acid grassland with small areas of upland heath dominated by common heather. Patches of gorse occur on short, steep slopes on the hillsides.
Wetlands and Lakes
There are no significant lakes, fens or reedbeds in the LCA. The River Faughan, as part of the Foyle system, is important for Atlantic salmon as well as sea trout 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: low woodland cover of variable biodiversity value
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 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 control of grazing in broadleaved woodlands along streams to foster regeneration and if necessary, encourage replanting of canopy species
- encourage planting of native broadleaved woodlands, through appropriate grant schemes - rather than small conifer plantations which are of poor biodiversity and landscape value
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
- maintain and enhance floodplain grassland by restricting field or arterial drainage and encourage land-owners to promote environments for wetland birds - lapwing, curlew etc.
- 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: upland heathland is in decline in Northern Ireland, Ireland and Great Britain
Actions:
- promote membership of ESA and other environmental schemes through consultation with farmers and thereby
- control grazing intensity on existing heathland to encourage development of heathland and of heather of different ages
- control gazing intensity on some upland grassland to promote return to heathland
- discourage 'reclamation' to pasture fields around the heathland margins
- discourage afforestation
WETLANDS
Issue: important rivers, particularly for salmon
Actions:
- protect water quality of rivers through nutrient management and by reducing suspended sediments and deposition, 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 and quarries (noting the requirement of salmonids for clean water and river beds)
- monitor streams in relation to expansion of rural/urban housing and associated septic tanks/sewage treatment plants
