Biodiversity Action Plan 2016-2021

Objective 3 – Develop and Promote Best Practice in Terms of Rehabilitation for all Bord na Móna Bogs to Stabilise Former Peat Production Areas and Enhance Biodiversity

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.

Key Performance Indicators

Some of the key performance indicators in the period 2010-2015 were:

  • Draft rehabilitation plans detailed and lodged with the EPA for all bog areas. Each (draft) plan outlines the starting point (current baseline condition), sets clear aims and objectives to stabilise and rehabilitate the area, the necessary rehabilitation work based on best practice and research to date, a timeframe for completion, and the outcome of consultations with statutory and other relevant bodies to date
  • Final rehabilitation plans developed and implemented (completed or ongoing) for the Oweninny Bogs complex (Mayo, 2005 to 2013), Abbeyleix Bog (Laois, 2009), the Derrydoo-Woodlough bog cluster in East Galway (2012-2015) and the Clonboley Bog cluster in South Roscommon (2009 to present)

 

Field trials to determine effective approaches to biodiversity enhancement established at a number of bogs

  • Aspects of rehabilitation plans being trialled where possible such as in Boora Bog (Offaly – 1990s to present), Ballycon Bog (Offaly – 2006 to present), Mountlucas Bog (Offaly – 2014) and Templetuohy (Bruckana) Bog (Tipperary 2015; area under wind farm development footprint) (a complete list of areas rehabilitated is outlined in the previous section under Table X)
  • Field trials to determine effective and efficient approaches to biodiversity enhancement on cutaway bogs established at a number of bogs; these include drain-blocking, seeding (native and nursery species), fertiliser, reed transplant and seeding, and heather brash spreading trials
  • A Sphagnum inoculation field trial established at Kilberry Bog (2012)
  • An area of cutaway in Drinagh bog (31.2 ha) was developed to enhance breeding success of waders with a focus on Lapwing (2010)
  • Large scale rehabilitation trials established on Kilberry bog (rewetting – 38 ha in 2013) and Drumman (fertiliser and seeding approx. 30ha in 2010, 2011)
  • Targeted rehabilitation was carried out in parts of Derrycashel Bog (rewetting of ca. 20 ha in 2014)
  • Rehabilitation of the Srahmore Peat Deposition and Associated Facilities near completion
  • Restoration of raised bog areas identified during the baseline survey – to date 1,000 ha of raised bog has been restored (2009 to present)
  • Three Greenhouse Gas monitoring projects were established and funded by Bord na Móna on rewetted acidic cutaway (Oweninny), rewetted alkaline cutaway (Blackwater) and restored raised bog (Moyarwood). These projects were part of an EPA funded project – NEROS (Network monitoring Rewetted/restored peatlands and Organic Soils for climate and biodiversity benefits) – of which Bord na Móna was a member of the steering committee
  • Facilitation of a number of Masters research student projects and work experience for a number of Transition Year secondary school students
The wetlands at Finnamore's have attracted rare bird species such as Red-necked Phalarope

The wetlands at Finnamore's have attracted rare bird species such as Red-necked Phalarope

Building on this work the following actions can be outlined for the period 2016-2021.

Actions

  • Continue to update draft rehabilitation plans for all bog areas, with a view to final plans being developed and implementation in line with areas of cutaway bog available
  • Establish further rehabilitation field trials and build on existing knowledge in relation to habitat management and GHG emissions
  • Continue to implement the Bord na Móna Raised Bog Restoration programme
  • Finalise rehabilitation of the Srahmore PDA in Co. Mayo
  • Develop habitat and species management guidelines to be based on rehabilitation and restoration work carried out on Bord na Móna bogs which can be translated to other peatland areas

These actions will require ongoing work including:

  • Update draft rehabilitation plans bi-annually to reflect updates in baseline survey and/or other targeted surveys, as well as changes in peat harvesting projections/requirements and/or different land uses proposed
  • Consider the rehabilitation plans in the context of adjoining land-uses, hydrology including ground water dependant terrestrial ecosystems (GWDTESs), national policies such as the National Landscape Strategy and relevant EU Directives including Habitats, Birds, EIA and Water Framework Directives
  • Finalise rehabilitation plans in consultation with statutory and non-statutory consultees and carry out implementation as areas come available; carry out Appropriate Assessment screening for completed rehabilitation plans in accordance with EPA licensing requirements
  • Establish further rehabilitation trials on cutaway bog areas: trials outlined for 2016-2021 include an additional Sphagnum inoculation trial, different establishment methods for reed and other peatland species and controlled water run-off (sluice control); establish trials specifically for targeted species and habitat management; support biomass trials as well as other potential commercial trials on appropriate cutaway bog areas
  • Continue to investigate the potential for breeding wader habitat across Bord na Móna cutaway bogs, continuing to focus on the Drinagh trial site

Left: Fly Agaric Mushroom. Centre: Hawkbit and Common Centaury. Right: Grey Heron.

Left: Fly Agaric Mushroom. Centre: Hawkbit and Common Centaury. Right: Grey Heron.

  • Develop habitat management measures particularly for Curlew, building on the results of the 2015 and 2016 breeding Curlew survey
  • Selection of additional research trial sites and establishment of trials to determine effectiveness of other potential management options for rehabilitation; facilitation of potential funding sources such as EU LIFE, LEADER and other research grants; communicate with potential project partners such as BirdWatch Ireland, Irish Peatland Conservation Council, Butterfly Conservation Ireland, National Parks and Wildlife Service, Inland Fisheries, and second and third level education and research institutions
  • Continue to monitor GHG emissions from restored raised bog at Moyarwood Bog (Derrydoo Woodlough complex) up to 2018
  • Support and work to develop GHG monitoring projects on woodland habitats developing on cutaway bog
  • Work with the research team in Trinity College Dublin on the EPA funded project “A framework for the restoration of Irish peatlands” and continue to work with National Parks and Wildlife Service on the restoration practices for the NATURA 2000 raised bog network; this will include hydrological assessment of rehabilitation measures and options for cutaway bog areas
  • Continue restoration work in Clonboley and Killeglan Bog cluster; continue with restoration work in other bogs and bog remnants identified as high conservation sites
  • Monitor rehabilitation in Srahmore PDA and implement final rehabilitation phases
  • Following on from all of the rehabilitation and restoration work, assimilate the data and outcomes to inform best practice guidelines for cutaway bogs and associated peatland habitats; promote the ecosystem services approach in relation to trials, rehabilitation and restoration projects

Key Indicators of Success

The key indicators of success of the actions will be:

  • Acceptance of rehabilitation plans on submission to EPA and other consultees
  • Implementation and completion of rehabilitation plans where possible and monitoring programme established
  • Successful establishment of further research trials and projects showcasing a range of rehabilitation and management options for species and habitat management and/or conservation within Bord na Móna bogs; increased area of raised bog restoration
  • Established projects and successful funding applications for a range of projects with relevant project partners

inform best practice guidelines for cutaway bogs and… promote the ecosystem services approach

  • Increased knowledge of GHG balance of cutaway bogs and restored bogs
  • Habitat and species management guidelines for Bord na Móna bogs to be based on outcome of all rehabilitation trials and monitoring
Launch of Abbeyleix boardwalk in 2014. This community-inspired project is nationally and internationally renowned.

Launch of Abbeyleix boardwalk in 2014. This community-inspired project is nationally and internationally renowned.

Rehabilitation and the Bord na Móna Bogs

IPC License Condition 10

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).

Terminology

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:

  • Coniferous Forestry: areas leased to Coillte for forestry (up to 4,000ha across the land holdings); trial areas established in 2010/2012 at Killinagh and Derrybrennan (Allen Group)
  • Aggregates: Derryarkin Sand and Gravel project, Co Westmeath (leased to Roadstone) (Derrygreenagh Group)
  • Resource Recovery: Drehid Landfill, Composting Plant and Landfill Gas Generating Unit, (Timahoe South Bog) Co. Kildare (Allen Group)
  • Composting: Kilberry Composting Facility, Kilberry Bog, Co. Kildare (Kilberry Group)
  • Waste: Ash repositories for: EPL – Cloncreen, Co. Offaly (Allen Group); WOP – Area 3, Blackwater Bog, Co. Offaly. (Blackwater Group); LRP – Derraghan Bog, Co. Longford (Mountdillon Group)
  • Peat Deposition: Srahmore Peat Deposition Area and associated facilities, Oweninny Bogs, Co. Mayo (Oweninny Group)
  • Niche commercial opportunities: biomass trials (1980s-2000s); aquaculture trials (2014-2016)
  • Wind Farms: Mountlucas Wind Farm, Co. Offaly (Allen); Bruckana Wind Farm, County Tipperary (Littleton); Oweninny Wind Farm, Co. Mayo (Oweninny)
  • Amenity: Lough Boora Discovery Park, Co. Offaly (Boora); Loch Doire Bhile, Littleton (Littleton); DerryounceWalkway, Portarlington (Derrygreenagh); Mountlucas Wind Farm walkways
  • Biodiversity: for example all bog areas restored under the Bord na Móna Raised Bog Restoration programme (2009-present), Lullymore wetlands and Butterfly Conservation Ireland site; parts of the Oweninny Bog Group and Mountlucas Wind Farm sites

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.

All rehabilitation measures will have a positive impact on biodiversity in general, with some areas becoming habitat and species hotspots according to local characteristics.

Triggers for Final Rehabilitation Plans and Implementation

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:

  1. Isolated areas of cutaway bog emerge but are dispersed within larger production areas Even though extensive peat extraction is ongoing, at this stage a general impression of what conditions will remain on cessation of peat extraction can be attained and possible rehabilitation and after-uses identified (preliminary outline of after-uses noted). At this point a draft rehabilitation plan can be developed, outlining main features that will be assessed. Annual reviews to identify newly cutaway bog areas are carried out each January and those areas are updated on a map on the Bord na Móna GIS system (Land-Use Maps).
  2. The final peat drainage infrastructure is installed and a decision is taken on the timeframe for cessation of peat production within the bog unit, i.e. what further depth of peat will be extracted, what acreage of bog will be required to meet market demands, etc. Generally at this stage the operations in the bog would be winding down and/or a realistic time plan established for closure of the bog unit. At this stage the draft rehabilitation plan will be reviewed and activated for the cutaway bog, ideally incorporating time frames, cost estimates and realistic objectives. Consultation with interested parties is conducted. This phase is represented in a number of bog areas such as the Oweninny Bogs (2003) and sites never developed fully for peat production such as Abbeyleix Bog (2009), Derrydoo-Woodlough Bog cluster (2013), and the Clonboley Bog cluster (2015).
  3. Hydrologically isolatable units of bog are available Rehabilitation can now commence within discrete areas of cutaway bog. For example, the Boora Parklands complex and Lullymore Bog (part of the Allen Ballydermot cluster of bogs).
  4. The entire bog out of peat production Only at this point can the complete rehabilitation plan be implemented, as well as decommissioning procedures for workshops and workstations. For example, the Oweninny Bog Group.

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.

Balycon wetland (rehabilitated in 2006).

Balycon wetland (rehabilitated in 2006).

Case Study: Oweninny Bog Group (1950s to 2015)

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.

Spreading Sphagnum on the Srahmore PDA in Co. Mayo.

Spreading Sphagnum on the Srahmore PDA in Co. Mayo.

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.

A number of mixed uses – wind energy, peat deposition and storage, nature conservation, amenity, turf cutting, blanket bog restoration, GHG monitoring - have been developed successfully for the Oweninny Bog Group

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.

Rehabilitation Trials 2010-2015

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.

rehabilitation_trial_01

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:

  • Re-profiling of drains and drain margins: Bord na Móna production bog is generally laid out in a series of long fields 15 m wide, separated by drains of < 1 m wide. When production ceases, drains with vertical edges that are sometimes quite deep (< 1.5m) are still present. These drains can act as a physical barrier to unfledged chicks. Re-profiling the edges of fields and infilling drains allows chicks to move from dry areas down to wetland vegetation to forage without difficulty.
  • Scrub removal: Maintenance of open areas and the management of scrub encroachment is also required to benefit these ground nesting bird species as they avoid any areas with emergent scrub, preferring open areas with lower incidence of predatory species such as Grey Crow.
  • Wetland enhancement by drain blocking: The introduction of wetland habitats provides valuable foraging areas for wader chicks. Raising waterlevels can also have the additional impact of limiting scrub re-growth, controlling scrub encroachment and maintaining large open areas.

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.

 

rehabilitation_trial_02

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:

  • Application of fertiliser to bare peat: This involved applying fertiliser to bare peat and establishing whether this was sufficient to kick-start seed germination and plant establishment.
  • Seeding bare peat with nurse species: Species such as Trticale are used as nurse species to promote revegetation, dying back as native plants establish.
  • Seeding bare peat with wetland/biomass crops: Reed canary grass is a known biomass crop and wetland species, and if established could provide a similar nurse crop function for other wetland species to establish.

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).

 

rehabilitation_trial_03

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:

  • Crop trials (2010): Crop trials were developed using the “nurse crop” principle where a crop is sown and fertilised in order to provide shelter for more naturalised vegetation to become established. Reed Canary Grass and Triticale were both selected as the nurse crops and received a once off application of fertiliser similar to the work in Drumman.
  • Reed trials (2013): Reed trials where reed seed (reedmace, Typha latifolia and common reed Phragmites australis) was collected from established wetlands offsite and stored before being sown at the correct time of year.
  • Seed trials (2013): Seed was collected along the high water mark on established wetland sites and then spread on the cutaway bog. The seed mix comprised many wetland species including sedges, reed and rushes.

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.

 

rehabilitation_trial_04

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. capillifoliumS. 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. capillifoliumS. 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.

Understanding the GHG balance in restored and rehabilitated peatlands

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.

Monitoring GHG at Blackwater reed bed (2011-2015).

Monitoring GHG at Blackwater reed bed (2011-2015).

Dr David Wilson monitoring GHG at Moyarwood Bog (bog restored 2012).

Dr David Wilson monitoring GHG at Moyarwood Bog (bog restored 2012).

The key actions relating to GHG monitoring listed in this plan are:

  • *Continue to monitor GHG emissions from restored raised bog at Moyarwood Bog (Derrydoo Woodlough complex) up to 2018
  • *Support and develop GHG monitoring projects on woodland habitats developing on cutaway bog
  • *Work with the research team in Trinity College Dublin on the current EPA funded project “A framework for the restoration of Irish peatlands” and continue to work with National Parks and Wildlife Service on the restoration practices for the NATURA 2000 raised bog network; this will include hydrological assessment of rehabilitation measures and options for cutaway bog areas

*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.

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