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
Holme & Woodwalton Fens IPA has been recognised as one of 165 Important Plant Areas in the UK.
The key features of this IPA are:
Calcareous fens with Great Fen-sedge
Woodwalton Fen is one of Britain's oldest nature reserves and together with Holme Fen, supports extensive areas of rich-fen and allied habitats. These National Nature Reserves are also recognised for their stoneworts, which can be found in the many fen pools and along the extensive ditch systems, also known for their rich aquatic flora. The area is now subject to restoration as part of the Great Fen Project.
Holme Fen is the lowest point in Britain, lying on the shore of the former Whittlesey Mere, and considered to be the finest, example of silver birch woodland in lowland Britain. More importantly the site contains approximately 5 hectares of rare acid grassland and heath and a hectare of remnant 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.
Over many years drainage of the surrounding farm land has caused the peat to shrink and this shrinkage has been recorded by the Holme Fen Post, a cast-iron column that was sunk into the fen in 1852. The column was sunk till its top was level with the peat surface, but it now rises some 4m above ground level. A series of lakes has been created in an attempt to increase the biological interest at the site.
About 5 km to the south east, Woodwalton Fen occupies a substantial site of 208ha. which features a mosaic of habitats, interlaced with stretches of tranquil waterway and footpaths. The area was dug for peat until the 1920s after which scrub invaded most of the site, but it now features a variety of fen habitats, including purple moor grass meadows, tall fen and scrub communities, woodland, and other assemblages of grasses, sedges, herbs and mosses.
At Holme Fen, the woodland consists of almost pure birch with a small number of oak trees. Around 450 species of fungi are found in the woodland and mixed scrub on the site. Where commercial peat cutting has led to the creation of areas of open water these support marsh plants such as golden dock. Other plants to be found include climbing corydalis, twayblade, meadow rue, saw sedge, heather, cross-leaved heath, purple moorgrass and the fen wood-rush.
At Woodwalton Fen, the moorgrass meadows contain ling, bog myrtle, tormentil and saw sedge. The flower-rich mixed fen which covers a significant area is home to meadow rue, yellow iris, swamp meadow-grass and great water dock and the 15 km of ditches support the rare carnivorous bladderwort and water violet. The site also supports two very rare plants; fen violet is found in only two other places in Britain, whilst fen woodrush is unique to the Great Fen in the UK.