Holme and Woodwalton Fens IPA
Location: Between Huntingdon & Peterborough, either side of the B660, which runs east from the A1.
Grid Reference: TL 220 873
These vast, low-lying and flooded landscapes are some of the best remnants of the great fens that once characterised East Anglia. Dominated by reeds and rushes, these watery worlds are home to rare flowers like fen violet and a rich diversity of freshwater algae called stoneworts.
Woodwalton Fen is one of Britain's oldest nature reserves and together with Holme Fen, supports a spectacular mosaic of plant-rich fen, woodland and heathland. These National Nature Reserves are also renowned for their stoneworts, beautiful algae which can be found in the clear pools and ditches along with many other rare plants.
The two reserves form part of the Great Fen Project, a 50-year project aiming to create a huge 3,700 hectare area of wetland in East Anglia.
Holme Fen is the lowest point in Britain, lying 2.75 metres (9 ft) below sea level. As well as the fen, it includes what’s considered to be the finest example of silver birch woodland in lowland Britain, home to around 500 species of fungi. The site also contains around five hectares of rare acid grassland and heath, and a remnant fragment of raised bog, an echo of the habitat that would have dominated the area centuries ago. It is the most south-easterly bog of its type in Britain.
Drainage of the surrounding farmland has caused the peat to shrink. In 1852, a cast-iron column was sunk into Holme fen until its top was level with the peat surface; today it now rises some 4 metres above ground level. Commercial peat cutting in the past has led to the creation of areas of open water, supporting marsh plants like sphagnum mosses and golden dock. Other plants to be found include climbing corydalis, twayblade, meadow rue, saw sedge, heather, cross-leaved heath and purple moorgrass.
Nearby Woodwalton Fen covers an impressive 208 hectares, a mosaic of habitats interlaced with stretches of tranquil waterway and footpaths. The area was dug for peat until the 1920s after which scrub and woodland developed, but a variety of fen habitats have since been restored. These include purple moor-grass meadows with more acid-loving plants like heather, bog myrtle, tormentil and saw sedge. The tall-fen beds, thick in reeds and rushes, support a wide range of flowering plants such as meadow rue, yellow iris, swamp meadow-grass and great water dock, while the 15 km of ditches support the rare carnivorous bladderworts and water violet.
This IPA also supports two very rare plants. Fen violet is found in only two other places in the UK (although worryingly it’s not been seen at Woodwalton Fen for several years now), whilst fen woodrush is unique to Holme Fen. Only eight plants of fen woodrush have been seen in the past 10 years.Image: Woodwalton Fen © Michael Trolove CC-BY-SA 2.0