An updated map of peat extent for Wales has been developed by the UK Centre for Ecology and Hydrology, with support from the British Geological Survey and Natural Resources Wales in support of the Glastir Monitoring & Evaluation Programme, commissioned by the Welsh Government. This map represents a considerable advance on previous attempts to map the deep peat resource of Wales and yields a significantly larger estimate than that based on the Soil Survey of England and Wales alone. This new map highlights the wide distribution of peatlands across much of Wales, with large areas of upland blanket bog in North east and North-central Wales (Migneint, Berwyn) and central Wales (Cambrian Mountains), as well as smaller areas of upland peat in and around the Brecon Beacons National Park. The new unified map also provides a much more detailed picture of the distribution of deep peat in the lowlands, many areas of which retain significant biodiversity interest. The Glastir Monitoring & Evaluation Programme was set up by the Welsh Government in 2013 to monitor the effects of the Glastir agri-environment scheme on the environment and ran from 2013 to 2016. Full details about this dataset can be found at https://doi.org/10.5285/58139ce6-63f9-4444-9f77-fc7b5dcc00d8

In support of the monitoring programme, the Welsh Government commissioned the UK Centre for Ecology and Hydrology, with support from the British Geological Survey and Natural Resources Wales, to develop an updated map of peat extent and condition for Wales. A full description and assessment of the peat map, including an analysis of current land-use and condition of peatlands, and their associated greenhouse gas emissions, are provided in Evans et al. (2015).

This map represents a considerable advance on previous attempts to map the deep peat resource of Wales (e.g. Taylor & Tucker, 1968) and yields a significantly larger estimate than that based on the Soil Survey of England and Wales alone (ca. 706 km2; ECOSSE, 2007). Another recent assessment of peat cover also utilised multiple data-sources (Vangeulova et al., 2012) but included the data from the Soil Survey of England and Wales, which were omitted from this study due to the scale of mapping, which tended to omit smaller peat units particularly in lowland areas, whilst over-estimating peat cover in some upland areas due to the merging of different soil types in mixed landscapes into peat-dominated soil associations.

The new map highlights the wide distribution of peatlands across much of Wales, with large areas of upland blanket bog in Northeast and North-central Wales (Migneint, Berwyn) and central Wales (Cambrian Mountains), as well as smaller areas of upland peat in and around the Brecon Beacons National Park. The new unified map also provides a much more detailed picture of the distribution of deep peat in the lowlands, many of which retain significant biodiversity interest. Large numbers of small peat units are found in many lowland areas of Wales, with the largest numbers mapped in Anglesey, Penllŷn, coastal Ceredigion, Pembrokeshire and Carmarthenshire. Larger lowland raised bogs occur at Cors Fochno on the Dyfi estuary, Cors Caron in Ceredigion, and Fenn’s and Whixall Moss on the border with Shropshire.