Area: 32.5 hectares.
Description and Reasons for Notification:
Greenamoor 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 is estimated to have decreased by at least 64% during the past six years, and the remaining 137 hectares of unimproved Culm grassland represents a highly fragmented and diminishing resource.
Greenamoor constitutes a large fragment of these remaining Culm grasslands. The site is floristically diverse and supports a Culm grassland community of particularly high conservation interest in Britain, as it is restricted to southwest England and South Wales and also known to occur in the New Forest.
Greenamoor is located approximately 10 km south-east of Bude and south of Week St Mary, within the catchment of a tributary of the River Ottery. The site is underlain by shales of the Upper Carboniferous Culm Measures, which have weathered to produce slowly permeable pelo-stagnogley soils, while alluvium and river deposits flank the stream valleys. Greenamoor supports examples of fen-meadow communities which have the main centre of their distribution in Devon and north Cornwall, and are typical of unimproved acidic grassland overlying the Culm Measures. The site is floristically rich; large areas are dominated by purple moor-grass Molinia caerulea, with abundant meadow thistle Cirsium dissectum, devil’s-bit scabious Succisa pratensis, sweet vernal-grass Anthoxanthum odoratum, tormentil Potentilla erecta, heath spotted-orchid Dactylorhiza maculata and saw-wort Serratula tinctoria. Wild angelica Angelica sylvestris, ragged robin Lychnis flos-cuculi and meadowsweet Filipendula ulmaria occur in less well-drained areas. Wet hollows within the tussocks of Molinia provide habitat for bog pimpernel Anagallis tenella, water mint Mentha aquatica, lesser skullcap Scutellaria minor and the nationally scarce wavy-leaved St Johns’-wort Hypericum undulatum.
Areas of shorter, Molinia dominated vegetation support abundant stands of sedges, including carnation sedge C. panicea, flea sedge C. pulicaris and tawny sedge Carex hostiana, together with cross-leaved heath Erica tetralix, sharp-flowered rush Juncus acutiflorus, lousewort Pedicularis sylvatica, bog asphodel Narthecium ossifragum, marsh violet Viola palustris and petty whin Genista anglica.
Additional species of interest include small numbers of lesser butterfly-orchid Platanthera bifolia, an orchid of declining distribution, a small population of the nationally scarce wood bitter-vetch Vicia orobus at its second known location in the county, and whorled caraway Carum verticillatum, another species of declining distribution, which is locally abundant within Greenamoor.
The site supports a diverse bryophyte flora (mosses and liverworts) including particularly well-developed populations of the Atlantic moss Hookeria lucens, occurring on the bases of Molina tussocks, an unusual habitat for this moss. Other species include Calypogeia muelleriana, Diplophyllum albicans, Sphagnum auriculatum and Dicranum bonjeanii.
Habitat diversity is further increased by the presence of a small block of deciduous woodland, fringing hazel coppice and willow scrub, water-filled ditches and a stream.