Wicken Fen IPA

Location: Cambridgeshire, south of Wicken on the A1123.

Grid Reference: TL 557 701

Wicken Fen IPA has been recognised as one of 165 Important Plant Areas in the UK.

The key features of this IPA are:

  • The species richness of stoneworts in base-rich fens
  • The species richness of vascular plants in base-rich fens
  • One of the best UK examples of threatened habitats of:
    Calcareous fens with Great Fen Sedge
  • Wicken Fen is one of the most important remnants of the once huge area of wetland which once covered the lowlands of Lincolnshire, Cambridgeshire, Suffolk and Norfolk.

    Since the 17th century the vast majority of this land area has been drained for intensive agriculture, with the result that less than 1% of the original wetland habitat survives today.

    The fen is divided by a man-made watercourse called Wicken Lode. The dykes, abandoned claypits and other watercourses carry a great wealth of aquatic plants, many of which are uncommon elsewhere, such as greater spearwort and lesser water-plantain. The fen also contains drier species-rich habitats but the main botanical interest is in the wetland communities, including the IPA qualifying stonewort flora with species such as dwarf stonewort.

    Plants you could see

    The original peat fen to the north of the Wicken Lode supports fen communities of carr and sedge. The carr scrub is largely of alder buckthorn Frangula alnus, buckthorn Rhamnus catharticus and sallow over a sparse vegetation of fen plants including the marsh fern Thelypteris palustris. The more open areas of sedge fen are typically of tall grasses, great fen or saw sedge Cladium mariscus, purple moor-grass Molinia caerulea, sedges Carex spp. and rushes Juncus spp. The deep peat soils of the sedge fen and centuries of traditional management have allowed rich plant communities to develop including milk parsley Peucedanum palustre, meadow rue Thalictrum flavum, marsh pea Lathyrus palustris, Cambridge milk parsley Selinum carvifolia, fen violet Viola persicifolia, (although this violet has not been seen on the site for some time), tubular water-dropwort Oenanthe fistulosa, marsh fern Thelypteris palustris, yellow loosestrife Lysimachia vulgaris, southern marsh orchid Dactylorhiza praetermissa and early marsh orchid D. incarnata.

    To the south of the Wicken Lode the area is of rough pastureland, reedbed and pools. The dykes, abandoned claypits and other watercourses carry a great wealth of aquatic plants. Many, such as greater spearwort Ranunculus lingua and lesser water-plaintain Baldellia ranunculoides are now uncommon elsewhere. They also support Internationally Important stonewort flora including Nitella tenuissima, the only recent site for this species in England.