Area: 10.98 hectares.
Description and Reasons for Notification:
Grimscott is a fragment of a formerly extensive moorland and mire system on the Carboniferous Culm Measures of North Cornwall. The unimproved "Culm Grasslands" that occur here support a vegetation complex comprising grassland, heath, mire and fen communities, several of which are nationally restricted in distribution. The extent of such sites in Cornwall has decreased by at least 64 percent during the past 6 years and the remaining 137 hectares of unimproved Culm grassland represents a highly fragmented and decreasing resource.
Grimscott is located approximately 7 kilometres to the east of Bude, within the catchment of the River Tamar. The site is underlain by sandstones of Upper Carboniferous Culm Measures, which have weathered to produce slowly permeable pelo-stagnogley soils, white alluvium occurs along the stream valley.
Grimscott supports a range of fen-meadow, mire and rush-pasture vegetation communities which are typical of unimproved acidic grassland overlying the Culm Measures. Of particular nature conservation importance here is the occurrence of purple moor-grass – meadow thistle Molinia caerulea – Cirsium dissectum fen-meadow, sharp-flowered rush – cross-leaved heathJuncus acutiflorus-Erica tetralix sub-community. This sub-community type, is restricted to the southwest of England, south Wales and scattered occurrences in the New Forest.
It is represented at Grimscott by a short sward supporting abundant meadow thistle and a rich sedge flora dominated by carnation sedge Carex panacea, with tawny sedge C.hostiana, common sedge C.nigra and oval sedge C.ovalis occurring frequently. Grasses are represented by Yorkshire fog Holcus lanatus and sweet vernal-grass Anthoxanthum odoratum, with purple moor-grass. Sharp-flowered rush is abundant, together with the herb species greater bird's foot-trefoil Lotus pedunculatus, meadow buttercup Ranunculus acris and marsh thistle Cirsium palustre.
Areas of Molinia tussock dominated vegetation are characterised by the occurrence of sharp- flowered rush, wild angelica Angelica sylvestris, common marsh-bedstraw Galium palustre, meadowsweet Filipendula ulmaria and common valerian Valeriana Officinalis. Of additional interest are the presence of whorled caraway Carum verticillatum, a species of declining distribution; and locally occurring populations of marsh cinquefoil Potentilla palustris. Bog moss Sphagnum spp. and ragged robin Lychnis flos-cuculi occur in the wetter hollows.
The site is bounded by a small fast flowing stream to the north and east, with associated willow carr, a type of wet woodland, dominated by willow Salix spp. and frequent alder Alnus glutinosa. Drier locations support coppiced hazel Corylus avellana and scattered holly Ilex aquifolium.