Ravarnet 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

• woodland is generally in the form of estate planting with scattered areas of wet woodland
• grassland is the dominant land cover, most of which is improved and of little biodiversity interest
• arable land is quite extensive and is an important habitat for farmland birds
• wetlands are common in the eastern half of the LCA with many lakes and associated areas of reedbeds, marsh and wet woodland.

Woodlands

Woodland accounts for just over 3% of land cover in this LCA. Woodland is found mostly in estate planting (Lowland woodland pasture and parkland) such as that at Larchfield and Homra House. The woodland at Corrys Glen, which incorporates Homra House is generally beech dominated with some oak and hazel. This area is also of importance for a diverse moss and liverwort flora in wetter areas. Larchfield Estate comprises several habitats including woodland, scrub, neutral grassland and river margin wetlands. Wooded areas consist of mature Scots pine with more native tree planting of hazel, oak, rowan and cherry, in recent times. This estate also attracts many species of birds such as the Goshawk and Buzzard. An area of oak and larch woodland exists at McKeowns plantation, adjacent to Larchfield, along with patches of hazel scrub in wetter areas and new oak planting. There are other areas of parkland which are predominantly broadleaved such as Ballylintagh Park and Fortwilliam. Scattered patches of wet woodland dominated by willow and alder are associated with wet marshy areas. Woodland is also found along the Ravernet River dominated by ash, willow, hazel and alder.

Grassland and Arable

Grassland is the dominant land cover in this LCA, most of this being improved. These areas have generally low biodiversity as a result of relatively intensive 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. Rough grassland is quite extensive and is found throughout the LCA both on drumlin tops and in hollows where it is often marshy.

Arable land is also quite extensive (although this includes grass reseeding) and is concentrated on land surrounding Larchfield estate, Annahilt and between Ravernet and Lisburn. Arable land is often of low biodiversity interest, but can be significant for farmland birds; in this LCA song thrush, linnet and yellow hammer have been recorded in areas classed as arable.

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. Generally, hedgerows are reasonably maintained and dense in this LCA, although they become poorer and more gappy on poorer land.

Wetlands and Lakes

The eastern half of this LCA, along the Ravernet River is characterised by the presence of many lakes with surrounding wet grassland and carr woodland. Lough Erne is a eutrophic standing water and has many associated habitats including reedbeds, marsh and scrub woodland, along with good moss, liverwort and lichen communities, all of which contribute to the biodiversity of this area. Ballykine Lough has been characterised as a Marl lake - these are the cleanest, clearest hard water lakes with specialised flora and are rare in Northern Ireland. This lough also has associated areas of fen and reedbeds. Many of the other lakes in this LCA also have associated wet woodland, mash and swamp areas all of which provide habitats for a wide range of flora and fauna, although the lakes themselves are not of great quality due to enrichment. Many wetland birds such as the mute swan, great crested grebe and snipe are also attracted to these wetlands.

There are no extensive areas of fen left in this LCA, some of the original areas have been drained and are now wet grassland or carr/scrub woodland. Existing areas are generally found around lake margins.

The Ravernet and Ballynahinch Rivers flow through this LCA and are both crowfoot rivers. The Ravernet has associated woodland of ash, hazel, willow and alder along its banks especially at Legacurry and Sprucefield.

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 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 new woodland planting (native broadleaves) through appropriate grant schemes, e.g. in field corners
• ensure that the examples of wet woodland are retained and not lost through drainage or landfill

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 unsown areas of species-rich 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 also beneficial to breeding birds

WETLANDS

Issue: important wetlands, especially lakes

Action:

• improve water quality of lakes and rivers through nutrient management and reducing suspended sediments

RIVERS

Issue: maintain good water quality in streams and rivers

Actions:

• promote and encourage existing good farming practices so that streams are not polluted by run-off from agricultural land or seepage from silage pits
• monitor effects of expanding rural housing on water quality

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