Area: 10.3 hectares.

Description and Reasons for Notification: 

Within Dartmoor National Park. 

Halstock Wood, on the northern edge of Dartmoor, is an example of an upland sessile oakwood, supporting a wide range of plants and birds. 

This ancient semi-natural woodland lies on east-facing slopes above the East Okement River, at an altitude of 250–300 m. The steep-sided valley bears thin, well-drained soils overlying a variety of rock types – predominantly chert, slate and tuff of Lower Carboniferous age. 

The dominant tree species is sessile oak Quercus petraea, largely of stored coppice origin, with ash Fraxinus excelsior and pedunculate oak Quercus robur interspersed throughout, and alder Alnus glutinosa on the river banks. Hazel Corylus avellana dominates the understorey, with occasional holly Ilex aquifolium and guelder-rose Viburnum opulus. The woodland floor shows a diverse ground flora including bluebell Hyacinthoides non-scripta, wood anemone Anemone nemorosa, pignut Conopodium majus, sanicle Sanicula europaea, common cow-wheat Melampyrum pratense and ramsons Allium ursinum and with bilberry Vaccinium myrtillus in more acidic parts. Occasional wet flushes occur on the lower slopes, and these are characterised by meadowsweet Filipendula ulmaria and opposite-leaved golden-saxifrage Chrysosplenium oppositifolium. At least 79 species of lichen occur in the wood, with a particularly well-developed Parmelietum laevigatae community on the trees: the species Graphina ruiziana, found on smooth-barked trees near the river, is a local species on Dartmoor. 

Some 30 species of bird breed in the wood, including raven Corvus corax, buzzard Buteo buteo, redstart Phoenicurus phoenicurus and wood warbler Phylloscopus sibilatrix. The woods along the East Okement, of which Halstock Wood forms a large part, are of particular interest as the site has one of the largest colonies of pied flycatcher Ficedula hypoleuca in southwest England.