DNFC visit to Timahoe Bog – 12 July 2014
1. Timahoe
Timahoe bog in Co. Kildare was once a
large expanse of Raised Bog lying to the
north of Allenwood and east of Derrinturn.
It was divided into northern and southern
portions by the road from Timahoe Cross
to Drehid Cross. Like most Raised Bogs its
original extent has been reduced over the
centuries by the hand cutting of sod turf for
fuel. During the war years, when fuel was
scarce, a special scheme was set up to
supply sod turf from the bogs in Kildare to
Dublin.
Today we will visit the northern part,
starting with an area of intact but degraded
Raised Bog that is still being cut for fuel.
2. Look Out For (a)
On the Raised Bog section, look out for the following species:
Heather or Ling - Calluna vulgaris
Cross-leaved Heath - Erica tetralix
White Beak-sedge – Rhynchospora alba
Deergrass – Trichophorum germanicum
Bog Asphodel – Narthecium ossifragum
Bog Rosemary - Andromeda polifolia
Round-leaved Sundew – Drosera rotundifolia
Bog Mosses – Sphagnum spp.
Heath Star-moss - Campylopus introflexus
Large White-moss – Leucobryum glaucum
Lichens - Cladonia spp.
3. Peat Stratigraphy
The Raised Bog at Timahoe has a typical east-Ireland
profile, with an upper layer of poorly humified
ombrotrophic peat (Younger Sphagnum) overlying a more
highly humified layer (Older Sphagnum). This is underlain
by the fen/bog transitional layer (Woody Fen) and finally
by the basal more minerotrophic peats - (Forest Peat) on the
uplifts and (Reedswamp Peat) in the hollows. Prior to the
mechanised production of sod turf, the top 50 cm layer of
the bog, including the vegetation, was stripped off and
deposited into the bottom of the previous year’s excavated
trough. This means that the resulting cutover peatland
consists of a basal layer of in situ peat, overlain by 0.5
metres of redistributed surface material.
Peat Stratigraphy at Timahoe
Younger Sphagnum
(Sphagnum-Eriophorum-Calluna)
~~~~~~~~~~~~~~~~~~~~~~~~~~
Older Sphagnum
(Eriophorum-Sphagnum-Carex)
~~~~~~~~~~~~~~~~~~~~~~~~~~
Woody Fen
(Scorpidium-CamptotheciumAcrocladium-Meesia-Betula)
~~~~~~~~~~~~~~~~~~~~~~~~~~
Forest Peat / Reedswamp Peat
(Pinus(PhragmitesQuercus)
Cladium)
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4. The Cutaway Peatland Areas
After the war, Timahoe bog was developed by Bord na
Móna for the mechanised production of sod turf. The turf
was produced using large electrically-driven excavators
known as “Baggers”. For mechanised production, the bog
was drained by a series of major trenches at 250 – 300 yd.
intervals. The peat was excavated from a vertical
facebank by a 2-metre wide cutter, and then deposited on
the bog surface using a 54-metre spreader arm. When the
remaining high bog became too narrow, the machine was
moved down and the turf spread on the cutover area.
Sod turf produced at Timahoe was used to fuel a power
station, built at Allenwood. The station opened in 1952
and continued to operate until 1992, finally closing in
1994. Sod turf was also sold to fuel merchants and to the
general public for domestic heating.
5. Look Out For (b)
Purple Moor-grass - Molinia caerulea
Crested Dogstail - Cynosurus cristatus
Common Cotton-grass - Eriophorum angustifolium
Glaucous Sedge - Carex flacca
Hairy Sedge - Carex hirta
Spotted Orchids - Dactylorhiza spp.
Marsh Thistle - Cirsium palustre
Wild Carrot - Daucus carota
Catsear - Hypochaeris radicata
St. John’s Wort - Hypericum spp.
6. Sub-peat Mineral Soils
The sub-peat mineral soils at Timahoe are “relict” soils, derived from limestone glacial drifts
left by the last (Midlandian) glaciation, or from sands, silts, clays or marls deposited in postglacial lakes. The drift derived soils, which occur at the highest elevations, were exposed to
soil-forming processes for the longest period prior to peat formation. These have leached
upper horizons and may be decalcified to 25-30 cm in depth. Silty and sandy soils, which are
of sedimentary origin, occur at lower contours. These soils were not exposed to soil-forming
processes, and may be strongly calcareous right to the soil/peat interface.
References:
Feehan, J. & O’Donovan, G. (1996) The Bogs of Ireland. University College Dublin.
Renou, F., Egan, T. & Wilson, D. (2006) Tomorrow’s landscapes: studies in the after-uses of
industrial cutaway peatlands in Ireland. Suo 57(4): p97-107
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