Summary An assessment of the afforested Peat Resource in Wales Summary of the findings of the report “A strategic assessment of the afforested peat resource in Wales, and the biodiversity, greenhouse gas flux and hydrological implications of various management approaches for targeting peatland restoration”. This report helps identify the opportunities for restoration of afforested deep peat and prioritise restoration efforts. Purpose Produce improved distribution maps of the peatland in Wales. Develop rule-based criteria to strategically assess the afforested deep peat resource in Wales, and its potential for delivery of ecosystem services. Establish priority sites for restoration based on these criteria. Develop a field assessment tool to evaluate a site’s potential for viable restoration to active bog habitat. Overview 18,092 hectares (ha) of woodland are estimated to be on deep peat soils in Wales. Of which 11,038 ha is owned by Welsh Government, with a little under 7,000 ha of that being under coniferous plantations. Restoration potential was assessed nationally and priority sites were mapped according to their potential delivery of ecosystem service benefit (carbon storage and sequestration, hydrology and biodiversity). Background Peatland in pristine or good condition provides a range of critical ecosystem services, including biodiversity, carbon storage and sequestration, regulation of stream base flows, water runoff and downstream flood peaks and nutrient regulation and retention. Peatlands are also sinks and sources of several natural greenhouse gases, particularly carbon dioxide (CO2) and methane (CH4). Peatlands that are in poor condition may be drying and oxidising, which will cause them to emit carbon, whereas peatland in good condition will be peat forming, and therefore sequestering carbon. More than 75% of deep peat soils in Wales are covered in semi-natural vegetation. Most of this is upland blanket bog, with significant amounts of fen and flush and, locally, lowland raised bog. These are all UK Biodiversity Action Plan priority habitats with UK and Welsh targets for habitat management and restoration. The focus of this work is the 18,092ha of deep peat which is under woodland cover. Assessment of peat resource Summary Definition Peat which is more than 50cm in depth is defined as deep peat under UKFS. A precautionary approach has been taken in this work, which means that the new map probably over-estimates the extent of deep peat. Distribution The most extensive areas of peatland habitat are the upland blanket bogs (23,400 ha) mostly in North Wales and the substantial area of wet modified bog (22,600 ha) mostly in the uplands of central Wales. Much of the forestry in Wales is also located in these areas because when they were initially planted to meet the country’s timber needs, it was the marginal agricultural land that was made available for the afforestation. Much of the deep peat in Wales is part of a mosaic of soil types rather than being in large blocks. Within the more expansive areas of peat there are often pockets of other soil types as well. National Assessment The focus of Forestry Commission Wales is to enable the greatest delivery of ecosystem services. This includes timber production and recreation, however, where trees were planted on deep peat (a practice which no longer occurs), it may be that restoring the peat to active bog habitat offers greater benefit across the range of ecosystem services. Sites which will be prioritised for restoration are those which have the greatest potential to provide benefits for biodiversity, improve the integrity of hydrological source areas and their capacity to regulate water flow and storage, and provide optimal greenhouse gas storage and sequestration. The national assessment scheme applies spatial datasets to assess five issues: a) current status of the peat; b) hydrological integrity of the site; c) consequence of restoration in terms of greenhouse gas emissions; d) ecological integrity of the site and e) climatic integrity of the site. The rule-based criteria score a site's potential for restoration so that the sites with good potential to become peat forming habitats have higher scores than those which will merely retain the existing peat. At a national level, each issue has been assessed and mapped separately (peat condition, hydrology, greenhouse gas balance, biodiversity, and climate integrity). The five issues are then combined using weighting factors to determine the final score for each site and produce the national map. Assessment of peat resource Summary Prioritisation and the Top 10 Sites The results of the national assessment reveal where the best opportunities for restoration are (excluding consideration of other factors beyond the scope of this study) – these are shown in green on the map. The sites which ranked in the top 10 (outlined in blue) are identified as priority sites. These priority sites have been assessed on the ground by an expert in the field to establish if the sites are really viable for restoration by applying the field assessment tool. These sites will be the focus for restoration efforts by Forestry Commission Wales. Options for sites not viable for restoration It is essential for the successful restoration of peatland that the water table can be raised and maintained. Where this is not possible, for example due to slope and cracking of the peat structure, an alternative to bog restoration must be sought. Options include creation of open heathland habitat, native or wet woodland, or continue to carry out commercial forestry on the site to lock up carbon and supply timber. These options need to be considered at each site that is not viable for bog restoration, according to the ecosystem service benefit and likelihood of success. Restoration Methods and Costs The primary aim in bog restoration is to keep the water table level high to allow sphagnum moss to accumulate. This is generally achieved by removing trees and blocking any ditches on site. The cost of this work varies greatly, but broadly speaking is in the region of £ 1,600 / ha. Assessment of peat resource Summary Management A site cannot be considered viable for restoration if success cannot be achieved in a reasonable timescale and that, once restored, the site cannot be self maintaining without a need for continual intensive intervention. Some ongoing management of these sites is expected. It is important to monitor the success of the works which have been undertaken and ensure the area is not deteriorating. The most likely ongoing problem is that of regeneration of conifer species. These can be manually removed or a low intensity grazing system may be implemented. Field Assessment A field assessment tool has been developed to enable forestry staff (such as planners and conservation managers) to evaluate all the areas of afforested deep peat highlighted in the national assessment and prioritise those sites where restoration is most viable. This tool is simple and easy to apply, information on soil type, peat depth, area and slope form the basis of this tool. It enables local decision making on the priority sites. It also guides managers away from committing resources to areas which are not viable or not going to deliver greatest ecosystem service benefit. Field Assessment Tool Next Steps There is an accompanying piece of guidance on forestry and restoration of peatland, which gives an indication of policy direction and outlines the need for a programme to be developed to assess afforested deep peat and future management. The Top 10 sites will be put into a programme of action to be undertaken on the Welsh Government Woodland Estate (WGWE) by 2027. The remaining afforested deep peat within the WGWE will be assessed using the Field Assessment Tool by 2017. Areas of afforested deep peat in private ownership will be subject to changes in felling licence conditions and we are in discussion with Welsh Government to ensure funds will be made available through Glastir for bog restoration where appropriate. The report, “A strategic assessment of the afforested peat resource in Wales and the biodiversity, greenhouse gas flux and hydrological implications of various management approaches for targeting peatland restoration” was conducted by Elena Vanguelova, Samantha Broadmeadow, Russell Anderson, Sirwan Yamulki, Tim Randle, Tom Nisbet and James Morison of Forest Research. This work was commissioned by Forestry Commission Wales, with support from the Countryside Council for Wales, with Welsh Government and Environment Agency Wales also represented on the steering group.
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