Ecological Survey of Drummin Bog 2020

‘Drummin Bog is in many ways a miraculous raised bog remnant in this part of Ireland. There are historical records of several raised bogs in the south-east but now they are only ghosts in the landscape present only in townland names such as Redbog.

Even when they were intact, the raised bogs of Ireland’s south-east would never have been large (<100ha). This would have been a simple reflection of the less suitable climate conditions of the south-east (drier) and the less-suitable landscape. So these smaller bogs would have been relatively quickly cutaway for fuel and/or drained to make them suitable for agricultural use.

So the fact that Drummin Bog has survived is unusual and highly fortuitous. It has, however, clearly decreased substantially from its original size through a mix of cutting and drainage over the last couple of centuries – this is visible from studying the Ordnance Survey Ireland historical maps available to view at This drainage, together with its small size does mean that Drummin bog would be classed as a relatively dry bog compared to other Irish examples…’

Habitat and Ecotope Survey and report of Drummin Bog, April 2021

Dr Fiona Mac Gowan, Consultant Ecologist

ABOVE AND BELOW: some of the images and text from Fiona’s study OF DRUMMIN BOG in Summer 2020

Sub-central ecotope

Moving into Sub-central ecotope is a significant step because Sub-central and Central ecotope types on raised bogs are the areas where peat is actively forming – these are the ARB (Active Raised bog) areas. The fact that these areas do exist at Drummin Bog is very positive. This means that work can be done to facilitate their growth and spread so that more of the bog can become ARB and regenerate itself and its special habitat.

Pockets of this ecotope exist in places where small pools have formed as a result of a process known as secondary rewetting. This is where either a small pond or an area at the base of an old peat bank has flooded and then filled with growth of Sphagnum S. cuspidatum if it remains very wet. This small area then essentially becomes a peat- forming area. If the ground around it stays wet then the Sphagnum growth will continue and spread. Sphagnum moss is a plant that changes the environment around it – in scientific terms the Sphagnum mosses are known as ‘ecosystem engineers’ because of their ability to change the environment around them – they make it wetter and more acidic and cause peat to form by inhibiting the activities of bacteria and fungi thus slowing down the full decaying processes.

The Sub-central areas at Drummin Bog were rich with several species typical of a healthy raised bog ecosystem with several different Sphagnum species, Bog rosemary, Round-leaved sundew, Hare’s tail cottongrass and Cranberry all recorded in these areas. Such variety of bog plants is a great sign of the health of the ecosystem and if these wetter sub-central conditions can be expanded a bit further then the quality of raised bog habitat here at Drummin has the potential to improve greatly.


There is not a large area of open water, much of it has filled in with the bog moss Sphagnum fimbriatum which has formed a green carpet over much of the pond area. This has lots of Many-headed bog cotton plants growing through it. This pond is very interesting from an ecological perspective as its vegetation portrays an ecological gradient from acidic to fen species. This is demonstrated with the southern end featuring species typical of alkaline conditions Bottle sedge (Carex rostrata) and pondweed (Potamogeton sp.) (Fig. 32) while the northern end was a carpet of green Sphagnum fimbriatum (Fig. 33) always found in acidic areas. The likely explanation is the depth of peat underneath i.e. there must be a certain depth of acidic peat beneath the acidic S. fimbriatum end but the acidic peat must be removed altogether and right down to the alkaline marl layer under the C. rostrata end.

Moths & Invertebrates

Invasive species

Concluding Ecological Assessment

– by Fiona Mac Gowan 2021

‘Drummin Bog is a precious area of biodiversity tucked away in the southern part of Co. Carlow and sandwiched by nearby Cos. Kilkenny and Wexford with none of these counties being known for their raised bog habitats. Therefore, although small, this geographical fact is reason alone to cherish the site. As this report and others commissioned by the Drummin Bog Project have shown, the site is a reservoir of species, hydrology and habitats different to anything else nearby.

The assessment of the raised bog habitats here concludes that while there are no areas of intact high bog habitat left at Drummin, the history of manual turf cutting over a long period of time has resulted in the secondary re-wetting of many areas. This in turn has ensured the retention of a group of micro-habitats often found on intact raised bog systems and thus ensuring the conservation of many typical bog species here in south Carlow. Due to this fact, the biodiversity value of Drummin Bog is very high in the greater context of the south-east of Ireland and indeed its status as the most south-easterly raised bog in Ireland gives it a national ecological importance.

For such a small bog, with an extent of approximately 4ha of open bog area, Drummin Bog hosts a variety of sub-habitats and different conditions as shown in the ecotope map (Fig. 15) and descriptions of Section 3. The small size makes the site more accessible to people and therefore more suited to interpretation thus making this a great site for ensuring more people get to have a bog experience. The presence of this bog area and its associated habitats is a terrific addition to an area already famed for its river and woodland habitats on top of a fascinating local history, thus Drummin Bog adds hugely to the tourism product of south Carlow/ south Kilkenny/ North Wexford.’