Dervlock Farmlands 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 cover around the average for Northern Ireland (c.5%), but four-fifths is coniferous forest of low biodiversity
• estate woodlands of major significance for broadleaved and mixed woodlands; most are unmanaged and may have high biodiversity value
• grassland cover slightly less than the NI average, but arable more than double
• although improved pastures account for most grassland, damp less-improved and rough grasslands are significant for floral diversity, birds (particularly waders) and butterflies
• important remnants of intact lowland raised bog; much bog lost to afforestation
• relatively un-polluted rivers with rare plant and animal species and important for salmonid fish

Woodlands

Woodlands account for about 5% of the land cover, around the average for Northern Ireland, but four-fifths of this is coniferous forest, predominantly State Forest, almost all of which has been planted on former peat bog. Lodgepole pine and Sitka spruce are the dominant species with occasional plantings of Scots pine, larch, Norway spruce and noble fir. The biodiversity of these forests is low and much reduced compared with the peat bog they replaced. The red squirrel has been recorded in Clare Wood.

Although broadleaved and mixed woodlands account for only a fifth of woodlands, there are locally significant areas associated with estates (Lowland woodland pasture and parkland). These include extensive woodlands at Dundarave; here there is a mixture of broadleaved, mixed and coniferous plantations. The latter are mainly of Sitka spruce with some older stands of Austrian/Corsican pine and Scots pine. Sycamore is the most frequent broadleaf but ash, elm and beech are also common; other species include oak, alder and horse chestnut as well as specimen trees. Rhododendron and snowberry are rampant in the understorey and limit the ground flora; however, where these species are less plentiful, ground flora is quite diverse. Further upstream, the R. Bush valley has a concentration of estates with woodlands, these include Ballylough House, Ballydivity, Ballyhibistock, Benvarden House and Lisconnan. Beech dominated plantations are common in many parts of these estates, but other frequent species include sycamore, ash, oak and elm. Scots pine and larch are intermixed in some of the woods together with specimen conifers. At Ballylough, the estate also includes wooded former cut-over bog with willows, alder and birch and some sycamore and ash on drier parts. To the east of the road at Ballydivity coniferous forest is fringed by broadleaves and east of Lisconnan spruce has also been planted on former bog. These estate woodlands have a low level of disturbance and contain veteran and fallen trees; they may have considerable importance to biodiversity especially as some of the houses and gardens are known to date back to the 1600s.

Another concentration of estates further east includes Stranocum House, Gardenvale and Gracehill. At Stranocum House woodland lines the meander scars of the R. Bush; tree species include beech, ash, oak and elm and there are also shrub and herb layers. Gardenvale has extensive woodlands with similar tree species and Gracehill, where the parkland is now a golf course, has extensive avenues and marginal plantations of beech, ash, oak and sycamore.

Broadleaved woodland with frequent ash, and alder and willow in damper parts, is also found along the steep banks of the Glenlough - Greenshields River, east of Ballymoney.

Although many of the cut-over bogs in this LCA have been afforested, there are others where natural colonization has led to woodland and scrub. Examples include much of the area of cut-over bog between the Islands of Carnmoon and Lisnagunogue where willow scrub is interspersed with rough grazing, and Iderown, near Gracehill, where birch dominates with willow around the edge (some wetter parts, including some edges may be classed as ). wet woodlandThe centre of Iderown is under conifer plantation.

Grassland and Arable

Grassland accounts for c.67% of the land cover; this is slightly lower than the average for Northern Ireland. Arable, which includes grass re-seeding, accounts for c.16% - which is nearly 2.5 times greater than the Northern Ireland average. Improved pasture is more than four-fifths of the grassland total. Although there are variations in the extent of 'improvement', these pastures generally have low biodiversity as a result of relatively intensive management. Some are sown grasslands dominated by ryegrass and few other species - low biodiversity is in-built. Others 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, which includes land under grass re-seeding, is scattered throughout the LCA except on the higher lands of the east and on lower flat surfaces dominated by peat.

Arable land is often of low biodiversity interest, but can be significant for farmland birds. Yellowhammer, song thrush, linnet, skylark and bullfinch have been recorded in areas with arable land in the LCA - note, however, that in this LCA arable land is intermixed with other habitats.

Biodiversity in areas of improved pastures and arable is often concentrated in hedgerows. These are a refuge for many woodland and farmland plants and animals. In this LCA, hedgerows are generally well maintained, dense and predominantly of hawthorn. On poorer land, for example in damp grasslands and areas of peat, they tend to be overgrown and gappy; some fields reclaimed from peat have post and wire fencing.

Areas of less-improved and rough grassland occur sporadically through the LCA, often around the margins of bogs. In the north between the Islands of Carnmoon and Lisnagunogue, rough grazing on former cut-over bog is intermixed with scrub (see above) and patches of gorse (whin). These damp grasslands are important for breeding waders including lapwing, snipe and curlew and the intermixed shrub vegetation, including gorse, can attract additional species such as linnet (which has been recorded in the Islands of Carnmoon), stonechat and whinchat. The marsh fritillary and wall brown butterflies have been recorded in the intermixed cut-over bog/rough grassland/scrub area of Lisnagunogue.

Heaths and Bogs

Peat bogs were once more significant in this LCA than they are today; most have been cut-over and many have subsequently been afforested. Examples include Carnlelis Bog, a lowland raised bog that has been cut-over with parts of the periphery reclaimed for pasture. Over two-thirds of the bog has been afforested with lodgepole pine and the remaining cut-over surface is dominated by common heather and purple moor grass. Carrowcloughan Bog similarly is mainly cut-over although there is a very small area of intact peat. Afforestation with Sitka spruce has also taken place in the south. Much of Moyarget Lower Bog, also extensively cut-over, has been planted with lodgepole pine. The remaining intact bog is dominated by mature heather with the lichen Cladonia impexa very abundant in places. There are remnants of an old hummock/hollow pool system, but the majority of the intact bog area is rather dry with low bog moss (Sphagnum) cover. Glassaneeran Bog also has intact bog, but it is similarly dry and with a comparable vegetation structure. The intact surface of Cloonty Bog, today around 30ha, represents the remainder of a large, complex, lowland raised bog system. However, the site is important to biodiversity because of the good surface microtopography with well developed hummocks and hollows and a very high Sphagnum moss cover, including some that are relatively rare - Sphagnum imbricatum and S. fuscum.

Throughout the LCA, sites of mechanised (compact-harvester) peat extraction were recorded in the early 1990s, with concentrations near Straidbilly, Manister-Iderown, the edge of Moyarget Lower and Bellisle. Although some show signs of recovery, it is a long process and the biodiversity is much reduced; there is often a dominance of cotton sedge with few other species and no bog mosses.

Wetlands and Lakes

There are no significant areas of standing water in the LCA; some ponds within estates could require survey. The River Bush and Dervock River have river water-crowfoot and the Bush and some other headwater streams are salmonid. The freshwater pearl mussel has been recorded at Stroan Bridge on the R. Bush and the otter is widespread.

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 at about the average for NI, but still low and of variable biodiversity value

Actions:

• enhance the biodiversity value of demesne/parkland woodland (which contributes significantly to the broadleaved and mixed woodland in the LCA) 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 new planting, particularly of native broadleaves through appropriate grant shemes
• retain native woodland that has colonized cut-over bogs; ensure that they are not lost through reclamation or tipping and that wet woodland round their margins is not affected by field and arterial drainage.

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 damp 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 beneficial to breeding farmland birds.

HEATH AND BOGS

Issue: raised bogs are of national and international importance

Actions:

• maintain the integrity of existing lowland raised bogs, particularly those with intact elements, by for example, preventing infilling, fly-tipping, fires, new drainage and new peat cutting
• restore raised bog habitats through appropriate water level management, removal of colonizing trees from intact bog, and phasing out peat cutting
• prevent new forest planting on raised bog

WETLANDS

Issue: important rivers for rare plant and animal species and salmonid fish

Actions:

• protect water quality of lakes and rivers through nutrient management and reducing suspended sediments. 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
• monitor streams in relation to expansion of rural/urban housing and associated septic tanks/sewage treatment plants
• monitor effects of peat cutting in relation to sediment and effects on spawning and nursery beds of salmonid fish.

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