Exmoor Mires

(Geophysical survey on Lanacombe; © ENPA 2013)

Mires, from the Old Norse word 'mȳrr', are bogs; wetland areas formed in conditions which are sufficiently cool and damp to inhibit the decay of dead vegetation that accumulates as peat. Such environments are globally rare, but the UK contains a significant proportion of the total. Although, at first glance, mires are perhaps unappealing places, they are actually important for a number of different reasons. Ecologically, they provide habitats for rare species while hydrologically, they store water and provide a buffer for rapid fluctuations in times of high or low rainfall. Possibly less obviously they are vast storehouses of carbon; peatlands globally hold one third of all terrestrial carbon, more than twice as much as the planet’s forests.

Mires are under great threat from drainage, peat exploitation and erosion. In the UK, 80% of the country’s peatlands have been damaged by human activity, resulting in the release of the equivalent of almost four million tonnes of carbon dioxide into the atmosphere annually, contributing to global warming. Exmoor’s mires are no exception having been especially heavily damaged by programmes of agricultural improvement involving the excavation of networks of drainage ditches, especially during the 19th century. Many of these ditches still operate, causing drying, degradation and decay of peat and the gradual destruction of the region’s remaining mires.

Since 2011, the Exmoor Mires Partnership, funded by South West Water (known as the Exmoor Mires Project until 2015) has been working to reverse this slow decline and restore Exmoor’s mires to a healthy condition. Partners in this include Exmoor National Park Authority, English Heritage, the Environment Agency, Natural England, the University of Exeter, the Exmoor Society and Exmoor landowners. This is achieved through the blocking of drainage ditches which allows the peat to retain water for longer, promoting wetter conditions and peat growth and increasing biodiversity.

Although often witness to a significant prehistoric human presence , the moorland areas containing Exmoor’s mires have generally seen less intense activity in recent millennia than the surrounding lowlands. As a result they are archaeologically rich with rare artefacts, sites and even landscapes being preserved under, within and around the peat. Indeed, the peat itself constitutes a record of past vegetation cover  that provides clues about the long-vanished environments in which our ancestors lived. Mire restoration involves the use of heavy vehicles and ground disturbance and thus has the potential to disturb or damage delicate and rare archaeological features, while the effects of restoration itself can obscure them over time. Accordingly, the project team includes a Historic Environment Officer, whose task is not only to provide advice and undertake work aimed at reducing any threats to valuable archaeology, but also to devise and coordinate a programme of research on aspects of Exmoor’s moorland archaeology most likely to be affects by restoration.

To date, this work has employed a variety of techniques. These range from simple walkover survey, aimed at spotting and recording previously unknown archaeological features, to more sophisticated methods such as geophysical investigation, palaeo-ecological analysis and the use of drones for high-resolution photographic surveying. So far, this has yielded a wealth of new information on archaeological topics as diverse as Mesolithic hunter gatherers, Bronze Age farming landscapes, Victorian agricultural improvement and 19th and 20th Century peat cutting. More work is ongoing, including research into World War Two military training, detailed study of the landscape of Exmoor Forest as created by the Knight family and analytical survey of the multi-period fields and settlements found on Codsend Moor. It is no exaggeration to say the Exmoor Mires Partnership has made a major contribution to the archaeology of the region’s moorlands. It continues to transform many aspects of our understanding of Exmoor’s historic environment into 2018 and beyond.

Lee Bray and Martin Gillard

Further reading

You can view further details about the project by visiting the Exmoor Mires website. This contains a variety of information on a range of research topics, including the historic environment and a list of historic environment publications generated by the project.