Peterborough Brick Pits IPA

Location: The IPA is found on the southern and eastern outskirts of Peterborough.

Grid Reference: TL 193 948

Peterborough Brick Pits 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 surface standing waters
  • One of the best UK examples of threatened habitats of:
    Nutrient-poor waters with Stonewort algae
  • This unusual landscape around the outskirts of Peterborough has been formed as a result of former brick clay extraction. This has left an extensive suite of pits and other excavations, some of which contain series of linear ponds and furrows, the most notable of which is Orton Pit.

    A mosaic of habitats has developed - scrub, grassland, bare clay, sedge, reed beds, small pools and open water pools where the pits have filled with water and now support communities of aquatic plants. The area is identified as being internationally important for stoneworts, with one of the richest florae in the UK.

    The open water of the ponds is characterised by pondweeds (fen pondweed, fennel pondweed, lesser pondweed and broad-leaved pondweed), an abundance of Chara species, mare’s-tail and spiked water-milfoil. The pond margins are typical of eutrophic or brackish conditions and comprise common reed, common clubrush, grey club-rush, lesser bulrush and bulrush.

    Orton Pit in particular is particularly noteworthy for the number of stonewort (charophyte) species present. The nationally rare bearded stonewort is most associated with the youngest ponds on the site. Another nine species of stonewort occur here, four of which are nationally scarce – hedgehog stonewort, lesser bearded stonewort, smooth stonewort and clustered stonewort.

    The marshy areas are dominated by a number of grasses, sedges and rushes, including creeping bent, jointed rush and the two spike-rushes. A great variety of herbs are present such as lesser water-plantain, early marsh-orchid and water violet. Of particular interest are stands of sea club-rush.

    Plant communities present in the dry grassland include common spotted orchid, pyramidal orchid, bee orchid and greater burnet. Other scarce plants include lesser bulrush, fen pondweed and horned pondweed.