Raised Bogs Restoration Project: Part 3
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RAISED BOG RESTORATION PROJECT AN INVESTIGATION INTO THE CONSERVATION AND RESTORATION OF SELECTED RAISED BOG SITES IN IRELAND PART 3 SITE REPORTS (A3 Format) A REPORT TO THE NATIONAL PARKS AND WILDLIFE SERVICE, DUBLIN. Larissa Kelly Malcolm Doak Marie Dromey June, 1995 TABLE OF CONTENTS Page No. SUMMARY DETAILS i LIST OF FIGURES ii SITE REPORTS 1 All Saint's Bog Offaly (566) 1 Bellanagare Bog Roscommon (592) 15 Camderry Bog Galway (240) 50 Carrownagappul Bog Galway (1242) 62 Cloonchambers Bog Roscommon (600) 82 Cloonmoylan Bog Galway (248) 99 Corliskea Bog Roscommon/Galway (219) 115 Firville Bog Tipperary (645) 131 Kilcarren Bog Tipperary (647) 145 Lisnageeragh Bog Galway (296) 157 Lough Lurgeen Bog Galway (301) 177 Redwood Bog Tipperary (654) 202 Appendix A Appendix B Appendix C Legend Key to Ecotope Map Symbols REFERENCES See Part I (introduction) of Report. SUMMARY OF CONTENTS This section of the report contains the detailed site reports for the sites for which the maps are drawn in A4 format. A paper copy of the Drains and Hydrochemistry Map, Vegetation Map, Ecotope Map, Landuse Map and Slopes Map accompany the site report. Transparent copies of these maps are contained in Appendix I. Also contained in Appendix I are the 1840s geological maps (1:10,560) for each site and a copy of the site boundary map (1:10,560). For the sites which were combined when filling in the Special Areas of Conservation forms there is only one site map. This is contained in the envelope of the first site name. The sites to which this applies are: Corliskea/Trien Kilcarren/Firville Ballykenny/Fisherstown Ballyduff/Clonfinane (i) LIST OF FIGURES Page No. Figure 1. Surface and Subsurface Topography on All Saint's Bog. 1 Figure 2. Meteorology Data for All Saint's Bog. 2 Figure 3. Meteorology Data for Bellanagare Bog. 16 Figure 4. Meteorology Data for Camderry Bog. 51 Figure 5. Meteorology Data for Carrownagappul Bog. 63 Figure 6. Meteorology Data for Cloonchambers Bog. 83 Figure 7. Meteorology Data for Cloonmoylan Bog. 100 Figure 8. Meteorology Data for Corliskea Bog. 116 Figure 9. Meteorology Data for Firville Bog. 132 Figure 10. Meteorology Data for Kilcarren Bog. 146 Figure 11. Meteorology Data for Lisnageeragh. 158 Figure 12. Meteorology Data for Lough Lurgeen Bog. 178 Figure 13. Meteorology Data for Redwood Bog. 203 (ii) ALL SAINT'S BOG, CO. OFFALY 1. SUMMARY OF SITE DETAILS NHA No. 566 1/2" Sheet: 15 Grid Ref: N 01 11 6" Sheet: OY 29 GSI Aerial Photo: N 163 1:25,000 Sheet: 17/19 NE Other Photo: SC 34062 Area (ha): 234 (total), 184 (intact) NHA Photo: 685:1-11 Date(s) of Visit: 14 and 15-6-94 (Ecology) 14 and 15-6-94 (Geohydrology) Townlands: Glaster, Ballynasrah, Kilnaglinny, Coolaghansglaster and Macnamanny or Fulough. 2. INTRODUCTION 2.1 BACKGROUND The site was identified as being of major importance by the Forest and Wildlife Service in 1985. A note on file describes it as an extremely wet bog with well developed hummock/hollow systems. Much of the N and W sides had been burnt 2-3 years previously. However Sphagnum species were regenerating well in these areas. It was given A status and included in the list of potential raised bog NNRs (Cross, 1990). Cross (op cit.) describes it as the only known example of a raised bog in Ireland with an extensive wet Betula woodland. Cross (1987) describes the Betula flush in detail from information gathered from releve data. These findings are outlined in Section 6.2.2. Corings (0-4m) were taken by Bord na Mona in 1986 to assess the suitability of the site for moss peat production. Humification degree and peat stratigraphy were not detailed. A SW/NE transect across the site was levelled by the Hydrometric section of the O.P.W in September, 1988. All Saint's was also visited by The International Mires Group in 1988 (Fojt, 1988). Their report includes a description of the site and some of the results of detailed investigations they undertook. These included: 1. Peat depths using a Hiller borer along the transect levelled by the O.P.W. 2. Water table depths (below surface) from holes in the peat. 3. pH and electrical conductivity of water from water table holes was sampled. 4. Vegetation was surveyed using 2m2 quadrats (20 in total). 5. A stratigraphic profile was examined. Using the O.P.W. levelling transect and the information obtained using the Hiller bore an illustration of sub-soil and surface topography is shown. This is re-produced in this report (Fig. X). O'Connor and Speight (1987), in a paper on insects new to Ireland, describe the occurrence of Dictenidia bimaculata in the Betula flush on All Saint's bog (hatching from the rotten wood of a dead Betula stump). This is a species associated with ancient European woodlands and is considered to be threatened in a European context. Coneycarn pit a quarry in the esker which runs to the S of All Saint's bog is a site with a number of rare plant species; Galeopsis angustifolium, Erigeron acer and Orchis morio. - 1- There is a note on file from Cross (1989) expressing concern that part of the esker ridge to the S hadbeen bought by Banagher concrete. He felt that the removal of gravel: could affect the hydrological system operating beneath the flush on the high bog; and/or cause drying out of the S side of the bog. All Saint's bog is also a refuge for the Little Brosna flock of Greenland Whitefronted Geese (Annex 1 species: Birds Directive). 1984/85 numbers are given in a note on file from Cross (1985). The NPWS own 112ha of the site which they purchased from Bord na Mona. Erin Peats own a large section (50ha) to the NE which they are currently exploiting for moss peat. 2.2 LOCATION AND ACCESS The bog is located 8km NNW of Birr and 6km S of Banagher. The Rapemills River borders the northern edge. A gravel ridge runs to the south, south of which the Little Brosna River flows. The site may be accessed from a small road which runs beside the gravel pit at its southern side. This small road is to the west off the Banagher to Nenagh road (L 113), just N of the Little Brosna River. A grassy track from beside an old house leads onto the southern side of the bog. 3. METEOROLOGY No meteorological measurements have been made on All Saint's bog. Rainfall data from the nearby Banaher rainfall station for the years 1951-80 indicate that the area receives approximately 844mm of precipitation annually (Figure X). Evapotranspiration from a wetland is most difficult to determine in practice. On a large exposed Midland bog such as Clara, wind fetches are long, and evaporation may occur at near open water rates when levels are close to surface and evapotranspiration occurs from the vegetation itself (Daly and Johnston, 1994). The recent Irish and Dutch work at Clara and Raheenmore suggests that actual evapotranspiration losses from the bog surface were found to be significantly more than estimated using potential evapotranspiration data from a regional, conventionally sited Meteorological Service station (Daly and Johnston, op. cit.). Figure X: Meteorology for All Saints 1951-81 Wet days at Portumna 90 80 70 60 50 40 30 20 10 0 Jan. Feb. March April May June July Aug. Sept. Oct. Nov. Dec. -10 Wet days 1960-84 Rain[mm] (Banaher) PE mm at Birr - 2- The above factors suggest that the year round actual evapotranspiration (AE) from All Saint's bog is greater than PE at Birr, site of the nearest synoptic station which had an average PE of 466.5mm/yr (1951-81) calculated by the Penman method. Annual evapotranspiration losses from the bog surface at All Saint's would therefore be greater than 466.5mm/yr. Potential recharge (PR) is the amount of water available for recharge after actual evapotranspiration has been accounted for, i.e. PR = P - AE. PR for this bog is therefore less than 377mm/yr. Meteorological data for All Saint's Bog (1951-1981) are summarised below: Rainfall (P) 844mm/yr Actual Evapotranspiration, (AE) >466.5mm/yr Potential recharge, (PR) <377.5mm/yr Raindays > 0.2 mm (annual {1951-1980}) 207 days 4. GEOMORPHOLOGY 4.1 TOPOGRAPHY OF THE HIGH BOG The whole bog is generally rather flat in the central part with slopes towards the edges particularly to the north. In some places the slopes may be steeper due to subsidence caused by drainage and/or peat cutting. 4.2 TOPOGRAPHY OF THE SURROUNDING AREA This bog is about 42m O.D. in height and lies 1km north-east of the Little Brosna River. High ridges of sands and gravels lie between the SW section of the bog and Little Brosna. 5. HYDROLOGICAL SYSTEM 5.1 GEOLOGY/GEOHYDROLOGY 5.1.1 Bedrock Recent geological maps by Hitzman (Chevron/GSI,1993) show that the area is directly underlain by calcareous shales. Waulsortian limestones (fossiliferous mudmounds) lie to the NE where there is higher ground. The calcareous shales have a low permeability and are classed as a poor aquifer. The Waulsortian limestone also has a low permeability. 5.1.2 Subsoils (See 6" 1840s Map) Data Availability No subsoils data were available for All Saint's bog apart from the initial 1840s GSI geology field sheets and recent fieldwork carried out for this study. Geology of Inorganic Subsoils The subsoil geology of this bog and surrounding area are dominated by sands and gravels.