Newtonbutler and Rosslea Lowlands  Biodiversity Profile

 

In the following account it should be noted that for consistency, the biodiversity section follows a 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 about 4% of the land cover, rather less than the percentage for Northern Ireland as a whole (c.5.6%)
• of this, only around one-seventh is in broadleaved or mixed woodland confined to small patches either on steep drumlin slopes, around lough shores or on cut-over peat
• grassland covers about 92% of the LCA, a high figure even for Northern Ireland, but may be over-estimated because many formerly improved grasslands are now less-intensively managed with rushes invading
• important wet grasslands, including fen-meadows that grade into species-rich marsh and fen
• highly important lake types, particularly marl lakes, with rare fauna and flora

Woodlands

Woodlands account for about 4% of the land cover, rather less than the percentage for Northern Ireland as a whole (c.5.6%); of this, only around one-seventh is in broadleaved or mixed woodland, which with the exception of some estate woodland is confined to small patches either on steep drumlin slopes, around lough shores or on cut-over peat. Cornagague Wood and Lough FNR is predominantly willow and alder wet woodland on cut-over bog, with birch and holly in drier parts and a diverse herb and ground flora; it is typical of these small wooded cut-over bogs. Wet woodland, or carr woodland, of alder and willows is also found around the shores of some of the many small loughs, as at Inver Lough. The woodland at Kockawaddy is one of the larger patches on drumlins; typically it is predominantly hazel and willow scrub with some taller ash trees.

Outside of Rosslea, much of which is now forested, the Knockballymore and Oakfield estates comprise the largest estate woods; beech predominates but there are also ash, horse-chestnut and lime, as well as several conifer species, including Scots pine. In parts there is a dense understorey of cherry laurel, but there are also abundant mosses and lichens. (Lowland woodland pasture and parkland)

Coniferous State Forest at Rosslea Manor/Spring Grove is dominated by Norway spruce, Sitka spruce and Scots pine, but there are several compartments of mixed broadleaves and conifers - with beech, ash, oak and sycamore planted alongside the spruces. There are other small compartments of oak, poplars, alder and mixed broadleaves. The forest has potentially greater diversity than some other State Forests; Priority Species recorded include red squirrel and pipistrelle bat. In the north, parts of Tully Forest extend into the LCA; these are predominantly Sitka spruce and lodgepole pine.

Grassland and Arable

Grassland covers about 92% of the LCA, a high figure even for Northern Ireland (c. 71% for NI as a whole) and of this four-fifths is improved pastures. However, this is probably an over-estimate because many of the improved pastures show evidence of declining productivity and a lessening of management; for example, many fields show an invasion of rushes and hedgerows are neglected. Generally, improved pastures are of low biodiversity because they are often sown rye grass pastures, have fertilizers and slurry applied, and are subject to repeated cutting for silage, or to heavy grazing. Frequently in lowland Northern Ireland biodiversity in improved pastures and arable land is confined to the hedgerows. Here, the hedges are very overgrown and gappy and do not offer the micro-habitats that enable a rich diversity of plants to become established, especially where grazing and trampling occurs through the gappy hedges. Hedges are, however, densely treed, predominantly with ash, though alder and willow are also common in the damp soils.

In the extreme north of the LCA, soils derived from sandstones give rise to rush-dominated acid grasslands whereas across the middle, extending from Newtownbutler to Rosslea, the heavy soils from the calp till are more neutral and can give rise to more species rich fen-meadows; further south limestone forms the bedrock and here too wet low lying land that is unimproved gives rise to rich fen-meadows that adjoin alkaline fen (see below). The Finn Floods ASSI is an unmodified mature flood plain section of the Finn River system. The mature river, with its alluvial flood plain and interconnecting eutrophic lough (eutrophic standing waters) supports a range of associated swamp, tall herb fen and inundation grassland vegetation communities with a rich diversity of rare and notable plant species. Part of the site is regularly used by the Upper Lough Erne, internationally important, wintering whooper swan population and it is a regular breeding wader site (coastal and floodplain grazing marsh).

Heaths and Bogs

Lowland raised bog is not extensive in the LCA, partly because any examples have been cut-over (and some of those colonised by wet woodland), but also because in these calcareous inter-drumlin hollows there may not have been full development into acid bog. The only remaining area of intact lowland bog is at Clonagun.

Wetlands and Lakes

This LCA is particularly notable for its concentration of marl lakes, that is calcium carbonate deposits, or marl, are precipitated out of the calcium - rich water to produce a marl lake. Several belong to the Nuphar/Elodea/Hippuris type, the cleanest, clearest, hard water lakes with the highest base status and most specialised flora. They are extremely rare and are vulnerable to phosphate accumulation. Annachullion Lough ASSI, Knockballymore ASSI and Summerhill Lough ASSI belong to this type, whilst other marl lakes include Burdautien Lough ASSI, Drumacrittin Lough ASSI, Kilroosky Lough ASSI and Magheraveely Marl Loughs SAC. Among the rare plants found are the submerged stoneworts, including bristly stonewort, rugged stonewort and at Knockballymore, lesser bearded stonewort; there are also rare aquatic beetles and the white-clawed crayfish.

Most of these lakes show a sequence from open water through reedbeds and fen to grasslands. At Magheraveely Marl Lakes SAC, the lakes are surrounded by an inundation zone containing significant stands of alkaline fen vegetation. This is generally composed of a sward that is very rich in sedges and herbs. Characteristic species include the lesser tussock-sedge, long-stalked yellow sedge and glaucous sedge. Other frequent species include marsh arrowgrass, quaking-grass and more notably, marsh helleborine, grass-of-Parnassus, knotted pearlwort and fen bedstraw, which are all scarce species in Northern Ireland.

There are also loughs classed as eutrophic standing waters, including some that belong to the Nuphar/Elodea/Hydrocharis type - a less enriched lake type centred on the southern Erne system.

These loughs, the fens and wet grasslands that surround them, are important for breeding waders, including lapwing, redshank, snipe and curlew.

The Lackey and Finn Rivers have the white-clawed crayfish.

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 to foster regeneration and if necessary, encourage replanting of canopy species
• encourage planting of broadleaved plantations, through appropriate grants, rather than the small conifer plantations which are of poor biodiversity and landscape value.

GRASSLAND AND ARABLE

Issue: variable biodiversity of farmland, but includes important wet grasslands

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, in particular fen-meadows, floodplain marshes and other wet grasslands, thus
• maintain and enhance floodplain grassland by restricting field or arterial drainage

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: important lakes - mesotrophic, eutrophic and a concentration of rare marl lakes, with rare species of fauna and fauna.

Actions:

• protect water quality of lakes and rivers through nutrient management and by reducing suspended sediments
• 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 streams in relation to expansion of rural/urban housing and associated septic tanks/sewage treatment plants
• monitor streams and lakes for sediment load and deposition arising from forestry and other activities, noting that incidences outside the LCA can affect rivers and lakes within

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