Greena Moor

Location: Week St. Mary, Cornwall

Grid Reference: SX 234 963

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Plantlife’s purchase of Greena Moor reserve helped to protect almost a fifth of the remaining area of a scarce and colourful habitat in Cornwall.

Greena Moor, in a somewhat isolated corner of Cornwall, is a reserve that needs an explanation. It’s an excellent example of culm grassland. Confusingly this has nothing to do with the flowering stems of grasses called “culms”, but refers instead to the rocks underneath the clay soil of the reserve. These culm measures are a kind of rock from the Carboniferous era that contains thin bands of impure anthracite or “culm”, found only in Cornwall, Devon, the New Forest and South Wales.

Mosaic of life

Always sparse, culm grassland suffered a catastrophic decline through agricultural “improvements”. The reserve is a fragment of what was once an extensive moorland and mire system, including large areas of culm grassland. It is fringed by wet woodland of alder and willows.

Two nationally scarce plants are found in the reserve: wavy St-John’s-wort grows in wet ditches and three-lobed crowfoot prefers muddy hollows. Also there are three species rare in Cornwall: whorled caraway is regarded as a good indicator of culm grassland and is abundant in parts of the reserve, meadow thistle prefers areas of damp grassland, and upright vetch grows among scrub and rocks on one north-facing bank.

Devil’s-bit scabious and saw-wort are common in some of the grassland, heath spotted-orchid and bog asphodel are plants of heathy areas, and bog pimpernel, lesser skullcap and water mint prefer damp hollows. Devil’s-bit scabious is important as the food plant for caterpillars of the marsh fritillary butterfly, which is active on the reserve in late May and early June. Reed buntings and meadow pipits are two of the many bird species present on the reserve.

Managing culm

Management of culm grassland typically involves grazing in summer, usually by cattle, to prevent purple moor-grass and scrub from swamping the other vegetation. The Cornwall Wildlife Trust works with a tenant farmer on our behalf to maintain this traditional management.

Purchase of the reserve was made possible by Unilever (Timotei). Please note that the site’s original name was Creddacott Meadow, but this was changed to avoid confusion with nearby Creddacott Farm.