Ballynahone Bog ASSI

The area is of special scientific interest because of its physiographical features and peatland flora and fauna. The peat sequence holds information on the history of local vegetation and climate and also international vulcanism for much of the Holocene (post 10,000 years before present) in the form of sediments, pollen, and volcanic glass shards (tephra).

Recently tephra (solid matter that is ejected into the air by an erupting volcano) have been identified in the peat column, a major layer relating to one episode of activity by the Hekla volcano in Iceland. This layer has been identified from many sites throughout the northern British Isles, offering a precise marker horizon and permitting more reliable correlation of peatland stratigraphy. The event may also be linked to the near extinction of Scots pine over much of Ireland at this time, as evidenced within the pollen record of the bog.

Biological interest relates primarily to the size of the site, in addition to the diversity of the vegetation and structural features, and the presence of rare and notable species. The intact surface represents one of the largest remaining areas of uncut lowland raised bog in Northern Ireland. The classic domed profile of the deep peat exhibits a wide range of characteristic vegetation and structural features, with pool, hummock and lawn complexes. The bog vegetation is characterised by a high percentage cover of Sphagnum mosses, ericoid dwarf-shrubs and other associated species, with the composition and abundance of these components dependent on local edaphic conditions.
Flat, water-logged lawns alongside pools are characterised by the prominence of such species as cross-leaved heath, bog asphodel, white beak-sedge and common cottongrass, over a Sphagnum moss carpet dominated by Sphagnum papillosum and Sphagnum magellanicum. The abundance of cranberry in these areas is also notable.
Typically, the pools are dominated by Sphagnum cuspidatum, with bogbean abundant in a number of them. Lesser bladderwort and great sundew are also frequent in some pools with the nationally rare Sphagnum pulchrum often occurring around the edges. Within the pool system, the main hummock-forming moss is Sphagnum magellanicum with Sphagnum papillosum and Sphagnum subnitens frequent. The liverwort pleurozia purpurea, a species generally associated with more oceanic areas to the west, is also found occasionally.

On the greater part of the bog plain the prominent species include heather, cross-leaved heath, hare's-tail cottongrass, common cottongrass and deergrass. Additional species which are also well represented within the sward include bog asphodel, white beak-sedge, with occasional patches of bog-myrtle also occurring. Leucobryum glaucum and Sphagnum mosses generally form scattered hummocks throughout the area.

The lagg surrounding the lowland raised bog has been extensively cut for turf, creating a mosaic of habitats which are dependant on peat depth and age of cutting. Vegetation communities vary from poor fen through purple moor-grass grassland and heath, to extensive areas of scrub and young woodland, mainly dominated by downy birch.

The peatland flora includes a number of rare species, including bog-rosemary, one of only four known sites in Northern Ireland, and four Sphagnum mosses; Sphagnum fuscum, Sphagnum imbricatum and Sphagnum molle, which form hummocks on the intact surface, and the nationally rare Sphagnum pulchrum which grows as a prominent pool edge species. In addition, the downy birch scrub and woodland, which has invaded much of the cutover area, supports a number of notable fungi including amanita fulva and russula flava.

The bog also provides an important habitat for breeding birds such as curlew and snipe and wintering species including birds of prey such as hen harrier and merlin.

The invertebrate fauna is largely characteristic of lowland raised bogs throughout Northern Ireland, with a predominance of acidophile, or acid-tolerant species. This includes the rove beetle lathrobium punctatum, the corixid bug hesperocorixa castanea, the dragonflies black darter and common hawker, and the water beetles hydroporus incognitus, hydroporus gyllenhali, Ilybius aenescens, Ilybius guttiger, graptodytes granularis and enochrus fuscipennis. The saldid bug chartoscirta elegantula has recently been recorded from the site; this is only the third record for this species in Ireland.
A further notable feature is the presence of the largest known colonies in Northern Ireland of the large heath butterfly.

Site Map and Related Documents

Ballynahone Bog ASSI Map (.PDF 810Kb)     Citation document (.PDF 135Kb)    Views About Management (VAM) document (.PDF 52Kb)