Buckinghamshire & Milton Keynes Biodiversity Action Plan Fens Habitat Action Plan Reedbeds Habitat Action Plan Fens Reedbeds Key associated species Bittern Otter Blunt Flowered Rush Reed Bunting Brown Galingale Reed Warbler Common Tern Sedge Warbler Curlew Snipe Grass Snake Teal Great Crested Newt Water Rail Green Sandpiper Water Shrew Marsh Fern Water Vole Marsh Helleborine Yellow Loosestrife Fens and reedbeds (including marsh and swamp) represent small areas of wetland habitat scattered throughout Buckinghamshire. These habitats tend to be restricted to places that are difficult to drain. They can occur around the margins of lakes or in the floodplains of rivers or can be what were once standing open water but have been gradually filled in by encroaching vegetation. The North Bucks fens are base-rich, soligenous fens, the water movement being predominantly lateral. Swamp is characterised by water table levels that are at, or above, the surface of the vegetation for most of the year. Swamps normally exhibit a species-poor vegetation when compared with fens. Marsh refers to vegetation occurring on mineral soil that has a water table close to the surface for most of the year, but not usually above ground level. Reedbeds are fens or swamps dominated by stands of common reed. These fragments of natural wetland habitats are of immense importance for nature conservation, supporting plants and animals that are specially adapted and entirely reliant on the habitat for their survival. 1 Current status in the UK Biological status 1.1 Large areas of wetland habitats in the UK have been lost to changes in agricultural practices. Fen, marsh, swamp and reedbed are widespread and scattered throughout the UK. The UK is thought to host a large proportion of the fen surviving in the EU. In other parts of Europe fen vegetation has declined dramatically in the past century. Intensive farming has resulted in the drainage of formerly wet areas 1 Buckinghamshire & Milton Keynes Biodiversity Action Plan Fens Habitat Action Plan Reedbeds Habitat Action Plan and their pollution owing to run-off from farms. Management of rivers and their catchment areas has contributed to the loss, although recent management has been more sympathetic. 1.2 Swamps are species-poor vegetation types, characteristic of open- water transitions with permanently or seasonally submerged substrates. Fens, marsh, swamp and reedbed vegetation communities are covered as swamp and tall-herb fens in Volume 4 of the National Vegetation Classification. 1.3 Reedbeds are fens or swamps dominated by common reed. In the UK they are geographically important in a global context and support characteristic communities of national important birds and invertebrates. There are about 5,000 ha of reedbeds in the UK but of the 900 or so sites contributing to this total only about 50 are greater than 20 ha, and these make a large contribution to the total area. 2 Current status in Buckinghamshire Cover and distribution 2.1 Fens and reedbeds are a nationally scarce habitat and have been identified as priority habitat types by the UK Biodiversity Group. Reedbeds, in particular, support characteristic nationally uncommon and rare birds and invertebrates. The North Bucks Fens support a number of locally uncommon vascular plant species. 2.2 The main vegetation-type for which the North Bucks fens are important is a form of base-rich fen meadow assigned to the NVC unit M22. This accommodates considerable floristic variation and the fens collectively support a number of locally uncommon species but few nationally uncommon taxa. However, both marsh helleborine and blunt-flowered rush meet the criteria suggested for national rarity in fen species. Information on the condition of the North Bucks Fens was published as a report to the Thames and Chilterns Team of English Nature (B D Wheeler 1996) and in Journal of Applied Ecology (B D Wheeler 1988). 2.3 A Phase 1 survey has been undertaken for The Greensand Trust area. Target notes from this survey and the national BAP for wetlands provide a source of information on marsh areas and wet areas. The Greensand Natural Area within Buckinghamshire possesses nine sites that support wetland interest. 2.4 Fens and reedbeds are not widespread in Buckinghamshire. The majority of fens are situated in central North Bucks, with the majority occurring at, or near, the headwaters of small stream valleys (valleyhead fens). A total of 19 sites were surveyed as part of the North Bucks Fen survey (Wheeler, 1996) in order to assess their current condition and identify changes that had occurred since previous 2 Buckinghamshire & Milton Keynes Biodiversity Action Plan Fens Habitat Action Plan Reedbeds Habitat Action Plan surveys in the 1970’s. Assessment for the areas of nine of the 19 fen sites has been provided and these sites cover a total area of 10 ha. 2.5 Fen communities are present at a number of SSSIs such as Frogmore Meadows, Kingcup Meadows, Pilch Fields, Temple Island Meadows and Tingewick Meadows. Tring Reservoirs (mostly in Hertfordshire) and Weston Turville Reservoir have reedbeds present. The largest areas of reedbed within the County are generally part of SSSIs but there are no available figures for the extent of the reedbeds within these areas. Small, isolated, linear strips of reedstand occur in the County along canals and around gravel pits and reservoirs. 2.6 Wet flushes and ponds on Littleworth Common used to support starfruit and small fleabane, both Red Data Book species. Marsh areas are present on the SSSIs at Moorend Common and Old Rectory Meadows 2.7 The Wolverton gravel extraction site in Milton Keynes is to be restored into a floodplain forest – including extensive (for the county) areas of reedbed. Trends 2.7 The close association between wetland habitats and watercourses has meant that the threats and changes that have been attributed to the degradation of watercourses have also greatly affected the marshes and fens of the County. Land drainage, infill and lowering of ground water levels have brought about losses of many of these important wetland habitats. 2.8 The North Bucks fen survey (Wheeler, 1996) revealed a deterioration to some degree for nine of the 19 sites surveyed. The estimate of deterioration was subjective, based on comparison of the current condition with records from the 1970s. 3 Current factors affecting the habitat Drainage and infilling 3.1 This can be for reclamation and agriculture. Pollution 3.2 This can include eutrophication from fertiliser run-off, chemical spillage and increased levels of effluent from sewage and water treatment works. Changes in the water table 3.3 This can be due to excessive ground water and surface water abstraction. 3 Buckinghamshire & Milton Keynes Biodiversity Action Plan Fens Habitat Action Plan Reedbeds Habitat Action Plan Climate change 3.4 This may result in different hydrological regimes and extreme environmental effects. Lack of appropriate management 3.5 If these sites are not managed, succession will occur and woody species such as willow and alder will invade. 4 Current action Legal status 4.1 The majority of the larger reedbeds are within sites designated as SSSIs. Many of the remaining sites are managed as part of nature reserves. No protection is available to linear tracts of reedbeds unless they are part of a Wildlife Site. 4.2 Of the fen sites in the North Bucks survey 9 sites are designated as Local Wildlife Sites and 2 lie within SSSIs. Management, research and guidance 4.3 The SSSI reservoirs that support reedbeds are Tring and Weston Turville. British Waterways own Weston Turville Reservoir with management of the SSSI undertaken by the Wildlife Trust. 4.4 Environmental Stewardship (HLS) has options that target reedbed and fen maintenance and restoration 5 Objectives 5.1 It is important that Habitat Action Plan objectives and actions are considered in conjunction with those in Generic Issues (see Generic Issues). All Generic objectives and actions apply to each individual Habitat Action Plan. The Fens and Reedbeds HAPs will contribute to the following targets in the UK BAP Fens T1 Maintain the current extent of the UK fen resource and diversity of fen types (see fen types 1-8). This target represents a "no loss" of habitat. T2 Maintain condition of fen habitat where already favourable and establish by 2010, management to secure favourable condition for all areas of fen currently judged as unfavourable. The target condition for all such areas should be favourable or unfavourable recovering by 2020. 4 Buckinghamshire & Milton Keynes Biodiversity Action Plan Fens Habitat Action Plan Reedbeds Habitat Action Plan T3 Initiate by 2020, the restoration of 2,800 ha of former fen habitat across the UK. T4 Establish 8 new landscape scale wetland complexes by 2020, at least 1 in each country in which fen is a major component along other wetland types and in which successional processes within the fen are allowed to proceed unchecked. This cross-refers to targets in the uplands, lowland raised bog, wet woodlands and reedbed HAPs. (Contributes to T3) Reedbeds T1 Maintain the extent of the existing resource of BAP habitat by active management and with no net loss (priority will be to maintain blocks of greater than 2ha, where appropriate). Links to Bittern SAP T2 Maintain the condition of wet reedbed habitat where already favourable and establish by 2010, management to secure favourable condition for all areas of targeted reedbed currently judged as unfavourable. The target condition for all such areas should be favourable or unfavourable recovering by 2020. T3 Continue creating reedbed from land of low nature conservation interest with the objective of expanding the BAP resource by 3,000 ha across the UK by 2020. T4 Establish 8 new landscape scale wetland complexes by 2020, at least 1 in each country in which reedbed is a major component along other wetland types.