Area: 1,006.7 hectares.
Description and Reasons for Notification:
Includes Holne Chase, a Nature Conservation Review site. In Dartmoor National Park. In Devon Structure Plan Dartmoor Nature Conservation Zone. Part owned by the National Trust and parts managed by the Devon Trust for Nature Conservation. Site previously called Holne Chase and Central South Dartmoor (part).
This site is important for its extensive area of ancient semi-natural oak woodland which displays a mixture of stand types. The woods support nationally important lichen communities and many species of breeding bird.
The greater part of the woodland lies on Carboniferous slates and mudstones which have been deeply incised by the fast-flowing River Dart and its tributaries. Within an altitude range from approximately 60 metres to 300 metres, the steep slopes of the valley system have a well-drained, fine loamy or fine silty, sometimes shallow soil with bare rock in places.
Sessile oak Quercus petraea is the dominant tree over much of the area, occurring with other tree species according to local soil conditions. Birch Betula spp. is often present on the poorer soils, particularly at the tops of hills or sometimes as pioneer species on neglected fields. Hazel Corylus avellana is locally abundant, while ash Fraxinus excelsior and wych elm Ulmus glabra are present on mildly acid, flushed soils. In some areas, on more freely drained soils, there are relatively extensive groves of small-leaved lime Tilia cordata, mostly derived from the former coppice. Stands of alder Alnus glutinosa and willow Salix spp. occur alongside the rivers whereas beech Fagus sylvatica and sycamore Acer pseudoplatanus are widespread throughout the site.
The ground flora is similarly varied, with sanicle Sanicula europaea, woodruff Galium odoratum and primrose Primula vulgaris growing on the more base-rich soils, and with common cow-wheat Melampyrum pratense, bilberry Vaccinium myrtillus, heather Calluna vulgaris and bramble Rubus fruticosus more common on the poorer soils of the slopes. In the darker, damper conditions of some north- facing slopes, a generally fern-dominated ground flora exists. Species present include scaly male-fern Dryopteris affinis, broad buckler-fern D. dilatata, lady fern Athyrium filix-femina and lemon-scented fern Thelypteris limbosperma. Royal fern Osmunda regalis is well established in places and Tunbridge filmy-fern Hymenophyllum tunbridgense occurs on some rocks along the River Dart.
Due to their long history, wide variety of aspects and pollution-free atmosphere, the broad-leaf woodlands support a rich lichen flora. A range of old forest community types are present, with the Lobarion community in the sheltered, moist valleys represented by Lobaria pulmonaria, L. laetevirens and L. scrobiculata. A very rich Graphidion community also occurs and includes the rare Graphina ruiziana, while the Pamelion laevigatae community characterises the more exposed conditions on the upper slopes. The site supports many rare species, such as Heterodermia obscurata, Parmeliella jamesii, Peltigera collina, Parmelia sinuosa and Sticta dufourii. Saxicolous lichens are particularly well developed on Ausewell Rocks and Sharp Tor.
On the higher valley slopes, the trees become stunted and scattered. Here, the woodland gives way to an open moorland occupied by a mosaic of bracken Pteridium aquilinum, gorse Ulex spp., heather, bell heather Erica cinerea, bents Agrostis spp. and fescues Festuca spp .
The woodland bird population is characterised by such species as raven Corvus corax, buzzard Buteo buteo, great spotted woodpeckerDendrocopus major, wood warbler Phylloscopus sibilatrix and pied flycatcher Ficedula hypoleuca. Woodland edge species include redstart Phoenicurus phoenicurus, while stonechat Saxicola torquata and whinchat S. rubestra breed on the adjoining woodland. Dipper Cinclus cinclus and grey wagtail Motacilla cinerea nest alongside the river, otters Lutra lutra traverse the area. The good quality of the waters also provide suitable conditions for the spawning of salmon Salmo salar and trout S. trutta.