Wicken Fen

Wicken Fen National Nature Reserve in Cambridgeshire is one of Britain's oldest nature reserves, purchased by the National Trust in 1899, and protects one of the last surviving fragments of the undrained fenland that once stretched across much of eastern England. The original reserve covers approximately 250 hectares of diverse wetland habitats including sedge fen, reed beds, and open water, representing a landscape type that has been almost entirely lost to agriculture across the Fens. The National Trust's Wicken Fen Vision aims to extend the protected area to over 5,000 hectares, creating a landscape-scale wetland corridor between Cambridge and the existing reserve.

Wicken Fen is one of the most intensively studied wildlife sites in Britain, with over 9,000 species recorded including more than 1,000 species of beetle and over 1,700 species of moth and butterfly. The hen harrier and marsh harrier hunt over the fen during winter and summer respectively, while bitterns boom from the reedbeds during the breeding season. Otters and water voles are present in the waterways, with Chinese water deer, introduced from Woburn, now a characteristic feature of the reserve. The fen's dragonfly fauna includes 23 species, with Norfolk hawker and variable damselfly among the highlights.

The sedge fen is dominated by great fen sedge (or saw-sedge), harvested commercially for thatching until the 1960s and maintained by continued cutting to prevent succession to scrub. Milk parsley, the food plant of the swallowtail butterfly, grows in the fen alongside marsh pea, marsh orchid, and fen violet. The lode-side vegetation includes yellow water-lily, flowering rush, and various pondweeds in the waterways. The expanding reserve lands support more dynamic habitats including developing scrub, rough grassland grazed by Highland cattle and Konik ponies, and newly created pools that attract wetland species.

Wicken Fen sits on deep peat deposits that accumulated over approximately 7,000 years in the waterlogged conditions of the post-glacial fenland. The surrounding agricultural land has shrunk dramatically through peat oxidation following drainage, dropping by up to 4 meters since the 17th century, leaving the undrained fen surface now significantly elevated above the surrounding fields. The underlying geology is Jurassic Oxford Clay covered by glacial drift deposits, with the flat topography and high water table creating the conditions for peat formation. The fen is fed by calcareous groundwater from the chalk aquifer to the south, creating mineral-rich conditions that support diverse vegetation.

The Cambridgeshire Fens have one of the driest and most continental climates in Britain, with annual rainfall of only 550mm and high summer temperatures reaching 25 degrees Celsius or more. The flat, open landscape experiences cold winter winds from the east, with ground frost common from October through April. Low rainfall and high evaporation in summer create water management challenges for the fen, particularly as surrounding drainage has lowered the regional water table. The continental climate produces distinct seasons with warm summers, cold winters, and spectacular autumn and spring wildlife activity.

The Fens were extensively exploited from at least the Roman period, with fish, wildfowl, reeds, and sedge providing livelihoods for fen communities. Major drainage schemes beginning in the 17th century under Cornelius Vermuyden progressively converted the fenland to arable agriculture, fundamentally transforming the landscape. Wicken Fen survived largely because its common rights holders continued traditional management including sedge cutting and peat digging. The economic importance of sedge harvesting for thatching material maintained the open fen character well into the 20th century, inadvertently preserving the biodiversity that depends on this management.

Charles Rothschild purchased the first plot at Wicken Fen in 1899 and donated it to the National Trust, making it one of the first nature reserves in Britain. Subsequent purchases and donations expanded the reserve through the 20th century, with National Nature Reserve designation following. The Wicken Fen Vision, launched in 1999, set an ambitious 100-year plan to expand the reserve tenfold through progressive land acquisition, creating a landscape-scale wetland extending toward Cambridge. The vision represents one of the most forward-thinking conservation projects in Britain, planning on generational timescales for landscape transformation.

The boardwalk nature trail provides accessible walking through the heart of the sedge fen, raised above the waterlogged surface with views across the characteristic fenland vegetation. The Lode waterway provides a canal-side walk with views over newly created wetland on the Vision lands grazed by Konik ponies and Highland cattle. The historic Fen Cottage displays traditional fenland life, while the 19th-century wind pump demonstrates the technology that once maintained water levels across the agricultural fens. Tower hides provide elevated views across the reserve, excellent for watching hunting harriers and other raptors.

The National Trust visitor center provides a cafe, shop, toilets, and exhibition space explaining the reserve's history and the Wicken Fen Vision. Car parking is available at the visitor center on Lode Lane, with additional access points on the Vision lands. The reserve is located approximately 15 kilometers northeast of Cambridge, accessed via the A1123 and minor roads. Bus services from Cambridge serve the village of Wicken, approximately one kilometer from the reserve entrance, and the reserve is accessible by bicycle from Cambridge via the Lode Way cycle route.

Traditional sedge cutting maintains the open fen character, preventing succession to dense scrub and maintaining the specific habitat conditions required by specialist fen invertebrates and plants. Water level management is increasingly challenging as surrounding agricultural drainage continues to lower the regional water table, requiring pumping to maintain fen wetness. The Wicken Fen Vision acquires former arable land and converts it to low-intensity grazing with natural flood management, allowing wetland conditions to develop over decades. Large herbivore grazing by Highland cattle and Konik ponies creates structural diversity on the new lands, mimicking natural processes that historically maintained fenland mosaics.