Barle Valley

Barle Valley (grid reference SS723423) is a 104.2 hectare biological Site of Special Scientific Interest in Devon and Somerset, notified in 1997.

The site includes the Somerset Wildlife Trust's Mounsey Wood Nature Reserve and Knaplock and North Barton SSSI notified in 1954. The site is within Exmoor National Park.

The Barle Valley contains extensive tracts of ancient upland Sessile Oak ancient woodland which exhibit variations in structure and species composition as a result of difference in past management, geology and topography. The diversity of the site is increased substantially by areas of valley mire, heathland and acid grassland. Eighty five woodland vascular plant species have been recorded including thirty one ancient woodland indicators from a single compartment. The meadows are one of the few sites for Great Burnet (Sanguisorba officinalis) on Exmoor. Springs emerging from the base of sandstone slopes generate nutrient poor acid mires dominated by Sphagnum and Polytrichum moss carpets. The lichen flora is exceptional both for its luxuriance and in the number of rare species. One hundred and sixty five taxa of epiphytic lichens are present containing a remarkably large proportion of ancient woodland indicators giving the Barle a very high index of ecological continuity.