Chippenham Fen is a remnant of the once massive Cambridgeshire Fens and is one of only four extant ‘wild’ Fens still surviving in the enormous Great Fen Basin - 99.9% of the former Fens have now been replaced by arable cultivation. Unlike the typical Cambridgeshire fens, which are below sea level, Chippenham Fen is 12m above sea level. Its 120 hectares of habitats include beds of saw-sedge and common reed, grazed wet meadows rich in wild flowers, meadows cut for hay, chalk grassland, carr woodland and scrub, and mature woodland. There are several ponds on the site and a system of dykes take water from the springs, in the south, to the Chippenham River, near its northern boundary. The fen lies in a shallow peat-filled depression underlain by a thick layer of chalky marl which rises to the surface in places. It is fed by rainfall and springs arising from the chalk aquifer, the clean, lime-rich waters of which support a rich aquatic flora plus a significant stonewort assemblage.
Plants you could see
More than 400 species of wild flowers have been recorded at the fen and it is the main British site for the very rare Cambridge milk parsley Selinum carvifolia and one of only 3 UK sites for early marsh orchid Dactylorhiza incarnata var. ochroleuca. The rich fen grassland is also home to blunt-flowered rush Juncus subnodulosus, long-stalked yellow sedge Carex lepidocarpa, glaucous sedge C. flacca and bog pimpernel Anagallis tenella Also present in this community are fragrant orchid Gymnadenia conopsea var. densiflora, marsh helleborine Epipactis palustris, marsh bedstraw Galium palustre, marsh lousewort Pedicularis palustris, grass of Parnassus Parnassia palustris and the locally rare common butterwort Pinguicula vulgaris, plus fen pondweed Potamogeton coloratus. To the north lie areas of fen and chalk grassland where the early marsh orchid and Cambridge milk parsley are to be found together with southern marsh orchid D. praetermissa, narrow leaved marsh orchid D. traunsterneri, common spotted orchid D. fuchsii, and an abundance of herb species including cowslip Primula vulgaris, restharrow Ononis repens, eyebright Euphrasia officinalis agg. and bee orchid Ophrys apifera. Columbine Aquilegia vulgaris also occurs sparingly here. The ponds and springs are home to a variety of aquatic plants, including water plantain Alsima plantago-aquatica, mare’s tail Hippuris vulgaris and frequent fen pondweed Potamogeton coloratus,
Image: Chippenham Fen IPA © Peter Wakely