|IPA Factsheet - Holme and Woodwalton Fens|
Site Description Holme and Woodwalton Fens are two of the largest surviving areas of relict fen vegetation in the East Anglian Fens. Before it was drained in 19th Century Holme Fen formed part of Whittlesey Mere. Holme Fen is now seen as a finest example of birch woodland in lowland Britain. By 1985 a series of lakes had been created in an attempt to increase the biological interest at the site. Woodwalton Fen was formerly a raised bog that surrounded Whittlesey Mere. Used previously as a site of bog peat extraction, the underlying fen peat has been exposed leaving only patches of the acidic peat at the surface. Open water habitats are also present at Woodwalton Fen in the form of ditches that hold some interesting aquatic species. Birch and alder woodland, fen carr and grassland are other habitats present at Woodwalton Fen. Holme and Woodwalton Fens are two of the largest surviving areas of relict fen vegetation in the East Anglian Fens. Together the two sites form the core of this IPA within a larger zone of opportunity surrounding and connecting the two; this area is already subject to a restoration effort as part of the Great Fen Project. The area has been subject to considerable drainage and over the centuries and the amount of peat shrinkage has been of considerable concern, as recorded against the Home Fen Post. Peat extraction also took place at Woodwalton Fen until 1920’s, the acid peat of the former blanket mire being stripped off for fuel to expose the calcareous peat below; there is no surviving blanket mire at Woodwalton but a fragment survives at Holme Fen. Woodwalton Fen is also used for flood storage. The area is also recognised for its stonewort populations.
Botanical Significance Noted for stonewort interest. The most significant vegetation present is the calcareous fen vegetation with Cladium mariscus and species of the Caricion davallianae. The site also supports other alkaline fen communities including the nationally rare Cirsium-dissectum meadow and supports a population of Viola persicifolia although this plant now occurs only sporadically as against the thousands present in the 70’s. Both Woodwaltonand Holme Fens support populations of Luzula pallidula and together they are considered of European Importance for stoneworts.
General Habitat Description · Woodland (Birch and carr) (major)· Bog and fen (peatland) (major)· Heathland Scrub (minor)
Conservation Issues Restoring fen from long-term arable cultivation Establishing appropriate water control systems to allow former fields to be appropriately inundated Developing appropriate water control strategy Facilitating the colonisation of restored land by vegetation from NNRs – establishing and maintaining plant transport processes.