Securing Biodiversity in Breckland - European Commission

CONTENTSExecutive Summary ........................................................................................................................... 6Glossary .......................................................................................................................................... 10Introduction .................................................................................................................................... 11The Breckland Region .................................................................................................................. 11Dynamic Changes in Breckland ................................................................................................ 12Recent Landscape and Land-Use Change ................................................................................. 16Changes in Fen, Wetland and River Valley habitats .............................................................. 17Breckland Conservation and the Need for this Audit ................................................................... 21Aims of the audit ......................................................................................................................... 25The Breckland bio-geographic region: climate, soil, vegetation and regional limits ..................... 27The Conservation Resource: Designated Areas ............................................................................ 37Breckland Biodiversity Audit: Methodology .................................................................................... 48Analysing Long-Term Trends in Weather ..................................................................................... 48Defining the Area of Species Record Capture .............................................................................. 50Collation and Sources of Species Records .................................................................................... 50Sources of Species Records ..................................................................................................... 50Duplicate Records ................................................................................................................... 54Record coverage and completeness ........................................................................................ 54Species historic to Breckland ................................................................................................... 55Data quality and resolution ......................................................................................................... 55Species lists and validation .......................................................................................................... 56Breckland Conservation Priority Species: Criteria ........................................................................ 58Treatment of Sub-species ........................................................................................................ 60Breckland Specialist Species: Criteria ....................................................................................... 61Collating and Synthesising Species Ecological Requirements ....................................................... 63Rationale for the Approach ..................................................................................................... 63Selection of Habitat and Ecological Process Categories ........................................................... 63Sources of Ecological Information ........................................................................................... 64Guild Analysis .............................................................................................................................. 69Current Conservation Management ............................................................................................ 70Data Mapping and Analysis ......................................................................................................... 71Findings of the Breckland Biodiversity Audit ................................................................................... 73Records and coverage ................................................................................................................. 73The Biodiversity Importance of Breckland ................................................................................... 82Differences in the Conservation Status of Rare Species in Breckland ....................................... 88Distribution of Breckland Conservation Priority Species .......................................................... 89Rarest and Most Widespread of the Priority and Specialist Species ......................................... 89Evidence of Climatic Change: Long-Term Trends in Weather ....................................................... 93Biodiversity Implications of the Changing Breckland Climate ................................................... 97Nitrogen Deposition: Potential Impacts and Mitigation ............................................................... 98Trends in Species Status: Extinctions and Declines .................................................................... 105Ecological Requirements of Breckland Biodiversity: Broad Habitat Associations ........................ 113The Feasibility and Usefulness of the Ecological Assemblage Approach ..................................... 115Delivery of Multiple Species by Integrated Species Biodiversity Action Plans......................... 121Breckland Species Assemblages .................................................................................................... 122Requirements of Dry Terrestrial Assemblages ........................................................................... 122Disturbance and Intensive Grazing Guild ............................................................................... 1224