Area: 466.60 hectares.
The heath fritillary is specially protected by being listed on Schedule 5 of the Wildlife and Countryside Act 1981 as amended; Dartford warbler is also specially protected under Schedule 1 of the same Act.
Heath fritillary, nightjar and the pink meadow cap are all priority species and lowland heath, dry acid grassland, parkland and wood-pasture and sessile oak woodland are all priority habitats of the UK Biodiversity Action Plan.
Dry heaths and old oak woods with holly and hard fern are habitats included on Annex 1 of the EC Directive on the Conservation of Natural Habitats and of Wild Flora and Fauna (92/43/EEC).
Dartford warbler and nightjar are both included on Annex 4.1 of the EEC Directive on the Conservation of Wild Birds (79/409/EEC).
Reasons for Notification:
This site is notified for nationally important lowland dry heath, dry lowland acid grassland, wood-pasture with veteran trees and ancient semi-natural oak woodland habitats. The fauna of the lowland heath includes a nationally rare butterfly the heath fritillary Mellicta athalia. The assemblage of beetles associated with the veteran trees is of national significance.
This site is located in the north-east of the Exmoor National Park within a few kilometres of the Bristol Channel. The majority of the site is on sloping ground with a northerly aspect ranging from 25 to 380 metres AOD. The underlying geology of the area is mainly Devonian Old Red Sandstone. These rocks give rise to nutrient poor, stony, acid soils, many of which are podzolic. The underlying rocks of the lower part of Dunster Park are Permo-Triassic marls and the clay rich soils here are less acid with a higher nutrient status.
The heathland found on this site is mostly classified as the western gorse Ulex gallii - bristle bent Agrostis curtisii type, which is restricted in distribution to the western parts of Europe and to south-west England and south Wales in the UK. Western gorse, bristle bent, heather Calluna vulgaris, bell heather Erica cinerea, european gorse Ulex europaeus and bracken Pteridium aquilinum are the main constituents of this habitat. On the highest part of the site the heathland becomes more like that normally associated with upland areas, with more frequent bilberry Vaccinium myrtillus and purple moor-grass Molinia caerulea and less frequent western gorse and bristle bent. The fauna of the heathlands is lowland in nature and includes several colonies of the heath fritillary, along with nightjar Caprimulgus europaeus and Dartford warbler Sylvia undata. The erratic ant Tapinoma erraticum, which is very rare in Somerset also occurs.
The wood-pasture together with associated parkland has a substantial number of veteran trees. By far the commonest species is sessile oak Quercus petraea and ash Fraxinus excelsior is also important for the saproxylic fauna and there are some black poplar Populus nigra ssp betulifolia present. Amongst the nationally scarce invertebrates associated with these trees are species of beetle and hoverfly.
The parkland contains areas of unimproved species-rich acid grassland mostly of the sheep’s fescue Festuca ovina - common bent Agrostis capillaris - sheep’s sorrel Rumex acetosella type. Amongst the many species present in the grassland is the nationally scarce clustered clover Trifolium glomeratum. There is an abundance of large anthills formed by the yellow meadow ant Lasius flavus. There is also a diverse fungal flora with waxcaps Hygrocybe species being well represented, including the pink meadow cap Hygrocybe calyptriformis. There are also areas of bracken and bramble Rubus fruticosus and scrub including some veteran elder Sambucus nigra and hawthorn Cratageus monogyna which add tote diversity of the site and enhance the habitat for the invertebrate and lichen species in particular.
The site also includes areas of ancient semi-natural sessile oak woodland. This woodland has a canopy dominated by sessile oak over a ground cover of bilberry with a sparse shrub layer including holly Ilex aquifolium. The ground flora of these woods is typical of woodlands of this type with several fern species including hay-scented buckler fern Dryopteris aemula and hard fern Blechnum spicant and mosses such as Dicranum majus.
The assemblage of breeding bird associated with the parkland and areas of sessile oak woodland is very diverse and includes species such as wood warbler Phylloscopus sibilatrix, redstart Phoenicurus phoenicurus, buzzard Buteo buteo and raven Corvus corax.