Almost all peatlands in Ireland have been modified to some degree and require some level of management to prevent further degradation and/or improve and enhance their condition. There is a growing recognition that investment in restoration and rehabilitation of peatlands can have enormous benefits for society both in terms of social and natural capital.
As part of Condition 10 of IPC Licensing Bord na Móna is required to develop rehabilitation plans for all the bogs areas within the licensed areas. While it is not possible to develop final rehabilitation plans for bog areas that are still in peat production as the final drainage plan and peat depths are not yet known, in the interim, using Lidar data and peat resource data we can develop draft rehabilitation plans based on the expected future character of the bog. Final rehabilitation plans have been developed for bog areas that were never in full production and currently being restored, such as the Derrydoo Woodlough Bog cluster in Galway. And also for bog areas that are completely out of production such as the Oweninny Bog complex in Mayo.
Trials and research into best practice inform the rehabilitation measures and a number of rehabilitation measures have been tested over the period 2010-2015.
Some of the key performance indicators in the period 2010-2015 were:
Building on this work the following actions can be outlined for the period 2016-2021.
These actions will require ongoing work including:
The key indicators of success of the actions will be:
The rehabilitation planning process within Bord na Móna has developed considerably over the last ten years to address the complexity of the process itself and the changing nature of the bogs as peat production continues. Condition 10 of each of the nine Bord na Móna IPC licenses relates to decommissioning and permanent rehabilitation of all bog areas. The main features of the process and how each aspect of Condition 10 has been addressed is outlined in the following sections.
It is important to recognise that peat production is an ongoing and long-term activity and will continue at a number of Bord na Móna bog areas for several years to come. During this time, the bog drainage and physical character will also change. Until then broad rehabilitation outlines can be drawn under draft rehabilitation plans, with definitive plans not being developed until peat production is within 1-2 years of cessation date. In the lead in time, there are (at minimum) annual updates with all Peat Production Managers in licensed bog areas and an ongoing baseline survey and continued research into rehabilitation methods and outcomes.
In 2013, the Ecology Team submitted draft rehabilitation plans for each of the Bord na Móna bogs. Following updates to the baseline survey and further rehabilitation trials, the plans were updated in 2015. The plans will continue to be reviewed on a bi-annual basis. The main elements required for rehabilitation post peat production are stabilisation of former bare peat areas largely attained through natural processes of revegetation which may require enhancement by targeted management such as fertiliser/seeding; surface manipulation and/or hydrological management (drain/outfall blocking). These basic features are outlined in the Bord na Móna Biodiversity Action Plan 2010-2015 with an update on trials and methods presented here.
Extensive research has also been carried out on potential commercial development of the cutaway bogs (agriculture, forestry, renewable energy (biomass, wind farms etc.) and eco-tourism). The outcome of this work is outlined in a number of publications including the recent Bord na Móna Biodiversity Action Plan 2010-2015 and the Bord na Móna Strategic framework for Future Use of Peatlands document (currently being updated, 2016).
It should be noted that the terms relating to restoration, rehabilitation and after-use can be defined as follows:
RESTORATION: the process of assisting the recovery of an ecosystem that has been degraded, damaged or destroyed. www.ser.org
REHABILITATION: refers to the primary objective of environmental stabilisation of the former peat production areas or cutaway bogs. This usually involves some form of management to ensure the revegetation of former peat production fields and/or habitat creation/enhancement (as outlined in Bord na Móna Biodiversity Action Plan 2010-2015). It may also include reclamation for agriculture and/or forestry, and/or amenity use.
REHABILITATION PLAN: outlines the current baseline condition of the bog on cessation of peat production and the proposed work plan, time frame and costing of work required to implement appropriate rehabilitation and monitor its effectiveness. The development and implementation of a rehabilitation plan for each bog area is an assurance that when Bord na Móna withdraws from industrial peat production at any site that it will do so in an environmentally responsible way. The rehabilitation plan will take consideration of other potential after-uses (such as renewable energy projects) that are proposed for any given bog area.
CRITERIA FOR SUCCESS OF REHABILITATION UNDER CONDITION 10 OF IPPC LICENSING: following cessation of peat production the main criteria are stabilisation of the former peat production areas (generally comprising bare peat fields and associated travel and transport and drainage infrastructure) and mitigation of silt run-off. These basic criteria are largely achieved by natural processes of revegetation with targeted rehabilitation work identified and implemented where required. While each cutaway bog area is rehabilitated in a manner appropriate to the environmental conditions of the site, the general rehabilitation approach is to facilitate the rewetting of cutaway where possible. Not all cutaway areas will have the capacity to be rewetted due to environmental conditions on the site (some of the cutaway will be naturally dry and develop woodland in the future), and land-use in adjoining areas. All rehabilitation measures will have a positive impact on biodiversity in general, with some areas becoming habitat and species hotspots according to local characteristics.
OTHER AFTER-USES: In practice a number of after uses may be proposed for rehabilitated peat production areas. These after-uses would generally require some form of manipulation of the site for a proposed commercial development (such as the Drehid Landfill Facility on Timahoe South Bog; the Mountlucas Wind Farm development); development of a biodiversity area for targeted species or habitats (such as at Drinagh) or an amenity area such as Lough Boora Discovery Park (walkways, cycle-paths etc.). In reality, all sites will comprise a mix of after-uses given the scale and potential of the bogs in relation to mixed use and multiple benefits, as in the case of the Oweninny Bog Group.
A number of after-uses have already been developed on parts of the Bord na Móna bogs. These include:
Any proposed after-uses implemented to date are generally covered by specific planning and mitigation conditions and/or appropriate licenses, such as the Srahmore Peat Deposition Area (part of the Oweninny Bog Group) which is covered by Waste Licence W199-2. The Strategic Framework for Future Use of Peatlands (2011) sets out the range of after uses that may be considered on any bog area and the general requirements relating to each option.
Each Bord na Móna IPC licensed area reports on progress of cutaway rehabilitation and potential future work as part of the Annual Environmental Reports (AERs) for each licensed area. This is carried out annually. Since completion of the baseline ecological work under the Biodiversity Action Plan 2010-2015 draft rehabilitation plans have been developed for all Bord na Móna sites and will be reviewed bi-annually. In terms of finalising rehabilitation plans a series of triggers can be outlined as follows:
These stages and triggers will continue to apply as peat production continues in all licensed areas for all bog units in Bord na Móna ownership. Within this framework, the most appropriate rehabilitation and/or after-use is based on the most up to date research and trials conducted and the conditions required for each potential after-use, while taking all primary and secondary factors into consideration.
Peat production in the Oweninny Bog Group began in the 1950s, supplying milled peat to the ESB peat-fired station adjoining the production areas at Bellacorick in North West Mayo. Bord na Móna developed two distinct bog areas – one at Bellacorick and one adjacent to Bangor Erris – which collectively covered 6,500 hectares of blanket bog. When the decision was reached to close the ESB power station in 2005, this led to the development of the Oweninny Bogs Rehabilitation Plan (2003). The plan was based on research on the emerging cutaway blanket bog carried out between 1996 and 2001 and the establishment of a number of site specific rehabilitation trials between 2001 and 2003.
A draft rehabilitation plan was circulated to consultees in 2001, with the final agreed plan in 2003. Implementation of the rehabilitation plan was carried out between 2003 and 2005, once the final drainage plan and site conditions were established. This involved an extensive programme of drain blocking and other targeted rehabilitation, carried out by the former peat production staff using the appropriate machinery.
In tandem with the rehabilitation, planning permission for an extensive wind farm was granted for the site in 2003, complementing the existing wind farm which had been built on the Bellacorick site in 1992, with a further planning application under review by the planning authorities. Furthermore, the Srahmore Peat Deposition Area and Associated Facilities was established in 2004/5 on 65 ha of the Bangor site to accommodate the spread and stabilisation of 450,000 tonnes of peat from the nearby Bellanaboy Gas Terminal site. Other more recent developments include GHG monitoring from the rehabilitated cutaway (2008-2013), the lease of 1,000 ha of the Bangor bogs to the National Parks and Wildlife Service in 2010 for the purpose of Red Grouse management, and ongoing projects with the local communities in relation to amenity use (walkway developments) of the sites.
Because of the scale of the site a number of mixed uses – wind energy, peat deposition and storage, nature conservation, amenity, turf cutting, blanket bog restoration, GHG monitoring – have been proposed and developed successfully together for the Oweninny Bog Group. The Ecology Team continues to monitor the rehabilitation outcomes at the site.
A range of rehabilitation measures have been trialled on the cutaway bogs in the period 2010-2015. In most cases the aim has been to accelerate revegetation in areas slow to colonise, although there have been species specific measures also carried out. Some of the trials are outlined here in detail.
Bord na Móna and BirdWatch Ireland established a trial area in 2010 on Drinagh Bog (Boora complex) in County Offaly with a view to developing management techniques for breeding waders on cutaway bog in Ireland. These techniques have been used in other countries in wet grassland and other wetland habitats.
The main objectives of this trial project were to investigate rehabilitation techniques to enhance the value of cutaway bog in the midlands for breeding waders and wintering water-birds, and where possible, to increase breeding wader numbers.
The main rehabilitation techniques included:
The main work of scrub clearance, re-profiling and drain blocking was carried out over 30 ha between 2010 and 2011. The site has been monitored annually since. Rehabilitation management has had a significant initial visual impact on the overall landscape of the trial area, creating a large open landscape comprising a mosaic of emergent wetland vegetation, drier exposed bare peat areas and some open water. Drain-blocking has also been successful and waterlevels are generally higher, with larger areas being inundated for longer periods of time. This is in contrast to the previous landscape with scattered scrub and fields with high margins.
RESULTS 2011: A total of 10 wader pairs were recorded in the trial area in 2011 compared to 2 pairs in 2010, prior to any rehabilitation management. Nearly all of the waders were recorded within the area cleared of scrub in 2010. The breeding wader population in 2011 comprised of Lapwing (4 pairs) (following numbers indicate pairs), Snipe (3), Redshank (2) and Ringed Plover (1). This compares to 2010 when the same area had Lapwing (1 pair) and Snipe (1 pair).
RESULTS 2014: The 2014 survey found that the new wetland area was still providing important bird habitat. Twenty-Eight breeding bird species were recorded in
the wetland including six Red-listed Birds of Conservation Concern in Ireland (BoCCI) species, Meadow Pipit (6 territories); Black-headed Gull (5), Tufted Duck (2); Lapwing (2); Redshank (1) and Woodcock (1) were recorded, and a further five Amberlisted BoCCI species: Snipe (6 territories); Little Grebe (4); Water Rail (4); Skylark (5) and Robin (12).
The new wetland habitats developing in Drinagh are most important for a range of species of conservation concern including breeding waders and other waterbird species such as Little Grebe and Water Rail. However, factors such as predation are preventing breeding wader numbers from increasing since 2011.
The wetland area also attracts a range of wintering bird species with species recorded in the past few years including Whooper Swan, Greylag Goose, Teal, Mallard, Lapwing, Golden Plover, Tufted Duck, Merlin and Hen Harrier.
During the baseline survey it was noted that while natural colonisation progresses relatively quickly on cutaway bog once peat production ceases, some sites are slow to revegetate and can remain bare. A number of trials were carried out on Drumman Bog (Derrygreenagh complex) in County Offaly to investigate measures to enhance vegetation.
The main rehabilitation techniques included:
The work on each trial was carried out in 2010 and monitored annually. Based on the work to date, it was concluded that a once off low-level fertiliser application to bare peat is sufficient to kick-start revegetation. This approach has been applied successfully on a number of sites now, with the focus on travel paths that tend to dry out in summer periods and areas generally slow to revegetate. The use of a nurse species was successful for stabilisation of bare peat but it is generally accepted that nutrient levels (such as phosphorus) is the main limiting factor. The trial areas continue to be monitored. Since establishment of the trials there has been ongoing pioneer habitat succession with birch colonisation leading to scrub development in places of former bare peat areas.
This trial has formed the basis for further targeted rehabilitation work on Ballycon Bog (2013), Lullymore (2014) and Cavemount (2015).
Kilmacshane Bog contains large areas of former production bog that are subject to the seasonal fluctuations of the River Shannon. The trial areas selected within Kilmacshane Bog are representative of the future cutaway bogs along the Shannon corridor that will be prone to seasonal inundation. The site is sufficiently dry during the growing season but wet during the winter months. A number of trials have been instigated here with the main aim of establishing vegetation cover on bare peat.
Three main trials were used here:
Results have been mixed to date with vegetation becoming established on former areas of bare peat. The crop trials worked best with the nurse crops allowing the establishment of wetland vegetation species including marsh arrow grass, mint and bulbous rush. The reed trials have not established widespread vegetation cover, possibly due to the site drying out during the summer months and/or seed viability. Issues that have been highlighted include control of the water levels to allow more water to stay on site during drier periods, grazers such as Irish hare have also had an impact on the developing vegetation. It should be noted that Kilmacshane Bog is host to large numbers of Whooper Swans in the winter months with the highest numbers in Ireland recorded from the bog in the winter period 2014/2015.
These trials have provided a great deal of information in relation to developing vegetation in difficult environmental conditions and they will continue to be monitored into the future.
There has been significant interest in recent years in a number of countries in farming Sphagnum to produce sustainable growing media for horticulture and other applications such as Sphagnum inoculation during bog restoration to increase diversity, re-establish peat bog vegetation and enhance restoration outcomes. A wide range of research has been carried out in several countries including Canada, Germany, UK and Estonia.
Sphagnum can be grown in suitable environmental conditions in degraded peatlands such as cutaway peatlands using paludiculture methods (production under wet conditions) as shown in Canada and Germany. With this in mind, the Bord na Móna Ecology Team established a trial at Kilberry Bog in County Kildare with the Bord na Móna Innovation Team to investigate the ability of different Sphagnum species to colonise and grow in suitable Bord na Móna deeper remnant peat cutaway.
Two different Sphagnum growth trials were set up in 2012 and 2013. Both trials implemented similar techniques as used in Canada and Germany to inoculate Sphagnum on cutaway bog. This involved site preparation (re-wetting), Sphagnum collection from a donor site, spreading Sphagnum fragments on the trial site and spreading straw mulch over the Sphagnum fragments to help water retention and protection of fragments from desiccation during colonisation. Care was taken to attempt to mimic the conditions of pioneer Sphagnum-dominated communities that have developed naturally in Bord na Móna cutaway thorough site selection.
The 2012 trial was set up with 24 5 m x 5 m plots in total. Five different Sphagnum species (S. capillifolium, S. papillosum, S. magellanicum, S. subnitens and S. cuspidatum) were used (and one blank plot). In addition there were 2 treatments, plots with straw and plots without straw. Fourteen plots were set up in 2013 (2.5m x 2.5m in size) testing 6 species (S. capillifolium, S. subnitens, S. magellanicum, S. papillosum, S. cuspidatum and S. palustre) with one blank and one replication ((6 + 1) x 2). All plots were covered in straw mulch.
Inundation during summer 2012 eventually destroyed half (12) of the original plots set up in 2012. Growth and establishment in the remaining 2012 plots has been relatively slow and only half of the plots with straw established some Sphagnum cover. The overall Sphagnum cover has also been quite low (generally < 1% with 2 plots reaching about 5% in 2015). Other vegetation has been colonising the plots (Bog Cotton, Rushes, weeds from the straw etc.) and some plots are now quite well vegetated (50-80% vegetation cover). Only 1 out of 12 plots in 2013 did not have some Sphagnum colonisation in 2015. However, general percentage Sphagnum cover values were relatively low (< 1% – 4%) in 2015. One plot (S. palustre) was the exception with relatively good colonisation and growth after the first year (10% cover) and continued relatively high cover in 2015 (~20% cover).
Summer inundation in 2012 and winter inundation in 2012/13 and 2013/14 has probably been the biggest constraint hindering the initial establishment of plots. Inundation acted by washing away the inoculating fragments of Sphagnum and the protective straw mulch. Relatively dry and hot periods such as in summer 2013 have also meant that the water levels dropped significantly, which is likely to have had a negative impact on colonisation and growth, although some Sphagnum has been able to survive and grow. Other environmental constraints to Sphagnum establishment at this site include the environmental characteristics of the residual peat. The average pH of the ground-water in the dip-wells was 6.0 in the initial dipwells and 5.3 in the newer dipwells with the average electrical conductivity being 104 μS. Sites with higher pH tend to be suited to development of poor fen and other habitats.
It would seem that the residual peat at the site in Kilberry is somewhat too decomposed and has a relatively high pH indicating that it is not optimally suited for raised bog Sphagnum restoration. The relatively high pH and conductivity is likely to be due in part to influence of the underlying limestonebased gravel sub-soils and the exposed fen peats. The site at Kilberry reflects the type of environmental conditions and constraints that would be found at some other potential deeper peat Bord na Móna cutaway sites. However, these sites have relatively variable remnant peat depths and environmental characteristics due to site variability, intensity of peat production etc.
Further trials will be established using a different sites in the period 2016-2021.
Peatlands are globally important in terms of greenhouse gas (GHG) emissions as it is estimated that they comprise up to 30% of the total global soil carbon pool*. As peatlands develop, the build-up of plant and animal remains creates a store of carbon in a waterlogged and anoxic environment. Because of this waterlogged condition, there is limited scope for microbes to break down the peat and release carbon dioxide.
When peatlands are drained, carbon is released mainly in the form of carbon dioxide and is also lost as dissolved organic carbon (DOC). This is also true for Irish peatlands and the role of managing Ireland’s peatlands has been highlighted in the National Peatlands Strategy (2015) as being important for future carbon accounting at a national level.
Most of the Bord na Móna bogs have been drained at some point. Where possible Bord na Móna is restoring raised bogs to peat forming conditions – stopping further release of carbon dioxide and in time restoring the carbon sequestration function of the bog. Bord na Móna is also funding research into determining the rate at which this switch occurs, and a project monitoring GHG emissions from a restored bog (Moyarwood in East Galway) was established in 2013, and is expected to continue to 2018.
Two GHG monitoring projects have also been carried out to inform rehabilitation measures on cutaway bogs – one in the rehabilitated Oweninny Bogs and one in a rehabilitated cutaway bog in Blackwater Bog (West Offaly). Both studies show that rewetting of the cutaway and establishment of wetland habitats such as poor fen and reed bed, reduces carbon dioxide emissions and leads in time to carbon sequestration.
Each of the studies has informed national carbon accounting measures carried out by the EPA, and Bord na Móna’s Carbon Working Group established in 2009, tracks policy developments and accounting approaches in consultation with the EPA Climate Action team.
The key actions relating to GHG monitoring listed in this plan are:
*The total amount of carbon stored in global peatlands and in global soils are both subject to considerable uncertainty and wide ranges of estimates. Estimates of soil carbon range up to 3,000 Gt C, but most recent estimates are in the range 1500-2000 Gt C. Estimates of carbon in peatlands stretch up to 600 Gt C, but International Peatland Society and Wetlands International figures are probably in the range 400-450 Gt C.