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Securing Biodiversity in Breckland: Guidance for Conservation and Research. First Report of the Breckland Biodiversity Audit

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Abstract

An innovative approach to evidence based conservation, The Breckland Biodiversity Audit (BBA) has developed an innovative, landscape-scale and evidence-based approach to strategic delivery of biodiversity. It provides a working example of the implementation of an integrated approach to biodiversity delivery in a region. The BBA is founded on a broad partnership of stakeholders, and harnessed the expertise, knowledge and recording effort of very large numbers of amateur naturalists, without whom this project would not have been possible. Their collective endeavours provide a working example of civil society in biodiversity delivery. The BBA identified priority species for conservation in Breckland, including large numbers of BAP, RDB and range-restricted species.  A key element has been to develop an evidence-based approach to understanding the requirements of these priority species and providing guidelines for their conservation. Ecological requirements of priority species for conservation in Breckland have been collated, and synthesised, integrating across numerous individual priority species to produce management guidance for multi-species assemblages.
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Securing Biodiversity
in Breckland
Guidance for conservation and research
First Report of the Breckland Biodiversity Audit
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Securing Biodiversity in Breckland:
Guidance for Conservation and Research
First Report of the Breckland Biodiversity Audit
Authors: Paul M. Dolman, Christopher J. Panter, Hannah L.
Mossman
Published By:
School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
Suggested citation:
Dolman, P.M., Panter, C.J., Mossman, H.L. (2010) Securing Biodiversity in Breckland: Guidance for
Conservation and Research. First Report of the Breckland Biodiversity Audit. University of East
Anglia, Norwich.
ISBN: 978-0-9567812-0-8
© Copyright rests with the authors.
Commissioned by the following organisations:
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Commissioning Group
Neil Featherstone (Chair): Brecks Partnership
Neal Armour-Chelu: Forestry Commission
Gen Broad: Suffolk Biodiversity Partnership
Bev Nichols: Natural England
Tim Pankhurst: PlantLife
Scott Perkin: Norfolk Biodiversity Partnership
Acknowledgements:
We are indebted to Martin Horlock (NBIS), Martin Sanford (SBRC), Gillian Beckett, Peter Harvey,
Helen Jobson (UEA/PlantLife), Yvonne Leonard, Ivan Perry, Ian Rabarts, Ian Simper and Doreen
Wells who collated and contributed large amounts of species records and autecological information
to the BBA. We are also very grateful to the many other individuals who provided invaluable help,
including biological records, autecological information, and information on management outcomes,
without these generous contributions the BBA would not have been possible. With sincere thanks
to: Isabelle Alonso (NE), Roy Baker, Stuart Ball, Helen Baczkowska (NWT), Jerry Bowdrey, Janet
Boyd, Andy Brazil, Shelia Brookes, Chris Burton (Forest Heath District Council), Dorothy Casey
(SWT), Piers Chantry (MOD), Adrian Chalkley, Phil Childs (Butterfly Conservation), Michael Chinnery,
Keith Clarke, Paul Cobb, Martin Collier, B.J. Collins, Tim Cowan (RSPB), Nigel Cuming, Joe Davis
(SWT), Paul Dickinson, Stan Dumican, Ken Durrant, Mike Edwards, Rafe Eley, Bob Ellis, Richard
Evans, Brian Eversham, Steven Falk, Francis Farrow, Jeremy Field, Richard Fisk, J. Fletcher, Andy
Foster, Garth Foster, Nick Gibbons, Mathew Ginn (NE), Gerald Gray, Gerry Haggart, Mike Hall, David
Hance, Rex Hancy, Ben Heather (SBRC), Sharon Hearle (Butterfly Conservation), David Heaver (NE),
Dave Hipperson, Chris Hitch, Peter Hodge, Sue Hooton (SCC), Graham Hopkins, Tim Huggins, Tony
Irwin, Chris Jones, Dick Jones, Ian Kileen , Adrian Knowles, Peter Lambley, Paul Lee, Tony Leech, Ian
Levett (NE), Diane Ling (FWAG), Lt. Col. S.J.A. Lloyd, Neil Mahler, Keith Morris, Mike Morris, David
Nash, Bernard Nau, Beth Newman (PlantLife), Peter Nicholson, Bill Nickson (NE) , Geoff Nobes,
Rosie Norton, Mary Norden (RSPB), Monica O’Donnell (NE), Nick Owens, Andy Palles-Clark (SCC),
Rob Parker, Scott Pedley, Tony Prichard, Chris Raper, Jonathan Revett, David Richmond, Phil
Ricketts, Rachel Riley (FC), Jim Rudderham (Elveden Estate), Bryan Sage, Ken Saul, Ann Sherwood
(ADAS), Mel Slote (NWT), Nick Sibbett, Duncan Sivell (Buglife), Matt Smith, Darrell Stevens (NWT),
Robin Stevenson, Alan Stewart, Tim Strudwick, Emily Swan (NE), Mike Taylor (NE), Mark Telfer, J.I.T.
Thacker, Heidi Thompson (NCC), Mike Toms, Kerry Vaughan (SWT), Andrina Walmsley (NWT), Jon
Webb, Jim Wheeler, David White, David Whiting (NE), Phil Withers. We also acknowledge the
invaluable contributions of many hundreds of additional recorders and members of the public who
over many years have submitted information to the County Biological Recording Centres (NBIS,
SBRC), county and national taxonomic recording schemes, or NBN.
Front cover: The Mining Bee Andrena hattorfiana (RDB: Rare) is one of many rare and declining
species recorded in Breckland. It is thought to depend on Scabious, as shown here, and the pink
pollen collected is stored in the pollen baskets on the legs. Therefore, it requires longer flower-rich
ungrazed areas of only occasionally disturbed vegetation, but also requires open, bare or sparsely
vegetated ground. Photographed near the river Wissey in STANTA © Nick Owens
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CONTENTS
Executive Summary ........................................................................................................................... 6
Glossary .......................................................................................................................................... 10
Introduction .................................................................................................................................... 11
The Breckland Region .................................................................................................................. 11
Dynamic Changes in Breckland ................................................................................................ 12
Recent Landscape and Land-Use Change ................................................................................. 16
Changes in Fen, Wetland and River Valley habitats .............................................................. 17
Breckland Conservation and the Need for this Audit ................................................................... 21
Aims of the audit ......................................................................................................................... 25
The Breckland bio-geographic region: climate, soil, vegetation and regional limits ..................... 27
The Conservation Resource: Designated Areas ............................................................................ 37
Breckland Biodiversity Audit: Methodology .................................................................................... 48
Analysing Long-Term Trends in Weather ..................................................................................... 48
Defining the Area of Species Record Capture .............................................................................. 50
Collation and Sources of Species Records .................................................................................... 50
Sources of Species Records ..................................................................................................... 50
Duplicate Records ................................................................................................................... 54
Record coverage and completeness ........................................................................................ 54
Species historic to Breckland ................................................................................................... 55
Data quality and resolution ......................................................................................................... 55
Species lists and validation .......................................................................................................... 56
Breckland Conservation Priority Species: Criteria ........................................................................ 58
Treatment of Sub-species ........................................................................................................ 60
Breckland Specialist Species: Criteria ....................................................................................... 61
Collating and Synthesising Species Ecological Requirements ....................................................... 63
Rationale for the Approach ..................................................................................................... 63
Selection of Habitat and Ecological Process Categories ........................................................... 63
Sources of Ecological Information ........................................................................................... 64
Guild Analysis .............................................................................................................................. 69
Current Conservation Management ............................................................................................ 70
Data Mapping and Analysis ......................................................................................................... 71
Findings of the Breckland Biodiversity Audit ................................................................................... 73
Records and coverage ................................................................................................................. 73
The Biodiversity Importance of Breckland ................................................................................... 82
Differences in the Conservation Status of Rare Species in Breckland ....................................... 88
Distribution of Breckland Conservation Priority Species .......................................................... 89
Rarest and Most Widespread of the Priority and Specialist Species ......................................... 89
Evidence of Climatic Change: Long-Term Trends in Weather ....................................................... 93
Biodiversity Implications of the Changing Breckland Climate ................................................... 97
Nitrogen Deposition: Potential Impacts and Mitigation ............................................................... 98
Trends in Species Status: Extinctions and Declines .................................................................... 105
Ecological Requirements of Breckland Biodiversity: Broad Habitat Associations ........................ 113
The Feasibility and Usefulness of the Ecological Assemblage Approach ..................................... 115
Delivery of Multiple Species by Integrated Species Biodiversity Action Plans......................... 121
Breckland Species Assemblages .................................................................................................... 122
Requirements of Dry Terrestrial Assemblages ........................................................................... 122
Disturbance and Intensive Grazing Guild ............................................................................... 122
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Wind-blown sand guild .......................................................................................................... 126
Physically Disturbed, Ungrazed Guild .................................................................................... 128
Importance of Areas of Scrub Adjacent to Open Habitats ...................................................... 138
Assemblages of priority species requiring sward mosaics ...................................................... 138
Grazing and No/Iinfrequent Disturbance Guild ...................................................................... 139
Woodland and open woodland guilds ................................................................................... 142
Deadwood and veteran tree guilds ........................................................................................ 142
Specific Requirement in a Variety of Habitats ........................................................................ 145
Management to Sustain Dry Terrestrial Assemblages ................................................................ 147
Current approaches to grass-heath management .................................................................. 147
Management Recommendations for Prioritiy Assemblages in Grass-Heath Habitats ............. 148
Complex Sward Mosaics ........................................................................................................ 159
Nested Heterogeneity ........................................................................................................... 160
Management for Assemblages of Lightly or Ungrazed, Undisturbed Conditions .................... 161
Management for Species of Physically Disturbed, Ungrazed Conditions: ............................... 163
Cultivated Margins Compared to Unsprayed Cereal Margins ................................................. 166
Delivering ungrazed, disturbed conditions outside the arable landscape ............................... 167
Targeting Ungrazed ‘Brownfield’ Sites ................................................................................... 168
Lightly or Ungrazed, Disturbed Open Space within the Forest Landscape .............................. 169
Grazing Susceptible Perennials .............................................................................................. 169
Ecological Requirements of Wetland Assemblages .................................................................... 171
StandingWater, Pingos and Fluctuating Meres ...................................................................... 171
The Relative Importance of Shaded and Unshaded Wetland Habitats ................................... 172
Littoral Habitats..................................................................................................................... 173
Grazing of Wetlands and Fluctuating Water Bodies ............................................................... 178
River Valley Assemblages ...................................................................................................... 180
Management to Sustain Wetland Assemblages ......................................................................... 182
Strategic Challenges to Biodiversity Implementation in Breckland ................................................ 185
Integrated landscape-scale strategies ........................................................................................... 190
Networks for resilience ................................................................................................................. 192
Recommendations ........................................................................................................................ 200
References .................................................................................................................................... 205
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Executive Summary
An innovative approach to evidence based conservation
The Breckland Biodiversity Audit (BBA) has developed an innovative, landscape-scale and evidence-
based approach to strategic delivery of biodiversity. It provides a working example of the
implementation of an integrated approach to biodiversity delivery in a region. The BBA is founded
on a broad partnership of stakeholders, and harnessed the expertise, knowledge and recording
effort of very large numbers of amateur naturalists, without whom this project would not have
been possible. Their collective endeavours provide a working example of civil society in biodiversity
delivery.
The BBA identified priority species for conservation in Breckland, including large numbers of
BAP, RDB and range-restricted species.
A key element has been to develop an evidence-based approach to understanding the
requirements of these priority species and providing guidelines for their conservation.
Ecological requirements of priority species for conservation in Breckland have been collated,
and synthesised, integrating across numerous individual priority species to produce
management guidance for multi-species assemblages.
Biological recording in Breckland
The BBA collated and examined over 800,000 species records, but highlighted a lack of integration
into the planning system among national, regional and taxonomically based recording schemes.
As well as relatively well-known groups such as vascular plants, moths and carabids information
was also collated for araneae, diptera, hemiptera, hymenoptera, molluscs, lichens and fungi and
other groups.
Mapped recording effort at a 1km x 1km scale showed:
Designated heathland and pingo sites are well covered.
Distribution data in and across arable and forested landscapes are patchy and taxonomically
biased, and further survey is needed in these areas.
Breckland is of major importance to biodiversity within the UK
The BBA has demonstrated the outstanding importance of Breckland for UK biodiversity. We have
established that:
At least 12,845 species have been recorded from Breckland.
Of these, 2,149 are priority species for conservation in Breckland, many more than
previously realised.
28% of all the priority BAP species in the UK occur in Breckland.
72 species have their UK distribution restricted to or have a primary stronghold in
Breckland. Although Breckland has long been recognised for its distinctive biodiversity, this
is the first time that the number of regional specialist species has been quantified.
There have been worrying extinctions and recent declines in some priority species
Remaining habitat is fragmented, species are isolated in small sites, and the landscape is hostile to
dispersal among these. Climate is demonstrated as already changing, with a loss of continentality,
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milder winters and increased winter rainfall in recent decades. Nitrogen deposition is a severe
threat, semi-natural habitats have received 1-2 tonnes of Nitrogen per ha over the last century.
15 species previously recorded in Breckland are believed to be extinct in the UK or England
The BBA collated recent records for 10 other species considered to be extinct nationally,
giving hope that these may survive in Breckland. These now need urgent survey to confirm
their status.
A further 25 species are thought to have been lost from the region (locally extirpated)
although they persist elsewhere in the UK.
For seven well monitored vascular plant taxa restricted to Breckland, more than half of the
populations (54%) have been lost (since 1985).
The ecological requirements of priority biodiversity
The BBA analysed the ecological requirements of the 2,000+ priority species for
conservation in Breckland to provide management guidance for their conservation.
The BBA has confirmed the importance of intensively grazed and physically disturbed
habitats, as previously recognised.
However, more priority species for conservation in Breckland depend on physically
disturbed conditions in an ungrazed (or only lightly-grazed) context. These should be
primarily conserved on farmland, on brown field sites, in the forest landscape and in large
extensive heathland complexes. Species of physically disturbed and ungrazed conditions
were significantly more likely to be considered extinct, than other priority species.
Approaches to management have been too homogenous. Many species require structural
complexity, including mosaics of different sward structure, juxtaposition of bare disturbed
soil with intact swards, juxtaposition of grazed and ungrazed elements, or patches of
scattered scrub in open habitats.
Rare species of woodland, veteran trees and dead wood also occur in Breckland.
Open standing water, littoral margins and open fen habitats are vitally important to
Breckland biodiversity and support many more priority species than shaded wetland
habitats (e.g. damp/wet woodland). Different priority species were associated with grazed
and ungrazed fen conditions and a range of vegetation structures is required.
The effectiveness of BAP species as figureheads to deliver wider benefits for priority biodiversity
A large proportion of the guilds were represented by one or more figurehead priority BAP species.
Overall, a series of habitat based prescriptions constructed on the basis of understanding the
requirements of BAP species would provide conditions for the majority of priority species.
However, there are notable exceptions, with a few specialist groups of species poorly represented
by BAP figurehead species, particularly wetland species associated with deadwood or detritus, and
dry terrestrial species associated with deadwood in open woodland or scrub mosaics.
The extent to which the known distribution of BAP species represents site priorities for their
representative guilds requires investigation, but is likely to be congruent.
Current conservation management is not sufficient to support priority biodiversity
Recently fallowed brecks have been virtually entirely absent from the Breckland landscape for the
last sixty years. The resource of early successional breck vegetation has aged, accumulating organic
matter, nutrients and favouring closed sward vegetation.
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Of the grass-heath resource for which we obtained information, 43% of the sheep grazed area was
managed by low intensity grazing, 70% of the area extent had no or few rabbits and disturbance
treatments covered less than 1% of the grass-heath extent. This is not compatible with conserving
the priority assemblages that depend on this resource. Approaches to management should be
revised, and best practice followed.
Recommendations for management of dry terrestrial habitats
Large numbers of priority species require heavy and intense grazing, this should be
implemented across large parts of most heathland sites.
Presence of heather (Calluna vulgaris) should not be an obstacle to heavy grazing as
retention of mature heather should not be an objective of management for priority species.
Physical disturbance should be applied to a substantial part of all terrestrial sites to provide
conditions required by large numbers of priority species.
Physical disturbance is a key tool in mitigating deleterious effects of nitrogen deposition and
eutrophication.
Heterogeneity, with areas of lighter grazing, structurally diverse swards, and the
juxtaposition of ungrazed elements (including ploughed or cultivated ungrazed margins
within or alongside heath sites) all provide for additional species assemblages.
Management should not be approached with the hope of keeping things from changing,
rather management should be dynamic, episodic and disruptive as gradual recovery from
grazing or disturbance provides conditions and structures not found on homogenously
managed sites.
Important assemblages that require physically disturbed ungrazed vegetation, including
bare ground and ruderal plant communities, are best supported on arable field margins,
through cultivated margin prescriptions, in the forest landscape, along lightly grazed
margins of large grazed heathlands, or in brown-field sites.
Large lightly grazed heathlands provide opportunities for recreation of breck arable and
ruderal habitats through mechanical disturbance and cultivation.
Brown field sites require mechanical management to create exposures of bare sand, gravel
and chalk.
Areas of uncertainty and recommendations for further research and survey identified.
Recommendations for management of wetlands: fen, pingos and meres
Scrub and woodland should be largely removed from fen and wetland sites.
A range of grazed and tall vegetation structures should be created.
On large wetland complexes this may be achieved by flexible extensive grazing, while on
smaller or wooded sites mechanical management may be required.
Strategic recommendations
Sites should no longer be considered in isolation, but management priorities should be considered
that strategically integrate across multiple sites in the landscape.
Adjacent sites should be combined into larger contiguous integrated units.
Biodiversity resilience of sites will be enhanced by developing connectivity networks that are best
achieved by:
Buffering existing track-ways and track verges with cultivated margins through agri-
environmental agreements in the arable landscape.
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Creating broad ruderal and disturbed highways for invertebrate and plant dispersal (by
percolation) through the forest landscape.
The Challenges
Strategic challenges are identified, including
The need to review the notified interest features for Sites of Special Scientific Interest.
The need to revise condition assessment criteria for Common Standards Monitoring.
Challenges in accepting uncertainty in management outcomes.
The importance of agri-environment schemes in supporting key biodiversity in the arable
landscape.
Opportunities in the forested landscape.
Please provide feedback to help further develop this work:
This project is the first phase of an ongoing and live partnership, building resilient human networks
and expertise. Throughout the BBA we have drawn on the best available evidence that we could
collate. However, we recognise that understanding remains incomplete. Mapped distributions
certainly have omissions. Broad assemblages are robust, but assignment of individual species to
assemblages is provisional in some cases, as our understanding of the requirements of many
species is currently incomplete.
We hope that through the publication of this report we can encourage more recorders and natural
historians with knowledge that could benefit Breckland’s biodiversity, to come forward and share
their insights, so that the partnership can improve the growing body of evidence and knowledge on
which effective conservation can be built.
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Glossary
Acronyms
BBA: Breckland Biodiversity Audit
CPERC: Cambridgeshire & Peterborough Environmental Records Centre
FC: Forestry Commission
NNR: National Nature Reserve
NBIS: Norfolk Biodiversity Information Service
NBN: National Biodiversity Network
NCA: National Character Area
NE: Natural England
NWT: Norfolk Wildlife Trust
SAC: Special Areas of Conservation
SBRC: Suffolk Biological Records Centre
SPA: Special Protection Areas
SSSI: Site of Special Scientific Interest
SWT: Suffolk Wildlife Trust
UEA: University of East Anglia
Aestivation: hibernation or diapause during a hostile season (e.g. during cold winter or dry
summer).
Assemblage: a collection of separate species that may co-occur.
Community: in plant ecology, attempts have been made to classify the underlying continuous
variation of plant assemblages, that vary along complex ecological gradients (e.g. of nutrients, soil
pH, grazing intensity, and climate) into distinct ‘communities’. This can be a useful tool, but
communities do not exist as clear entities, and local representations of a particular community will
be idiosyncratic and varied.
Benthos: organisms living on or within the sediment of aquatic habitats.
Guild: different species that share common functional attributes in terms of life history, foraging or
feeding strategy or habitat requirements.
Inquiline: is an animal that lives commensally in the nest, burrow, or dwelling place of an animal of
another species. These are not parasites, because parasites are defined as having a deleterious
effect on the host species, while inquilines do not.
Mere: a groundwater fed waterbody with a fluctuating water level due to a semi permeable base
and lagged response to seasonal fluctuation in the underlying water table.
Periglacial: processes involving intense frost or permafrost in regions adjacent to ice sheets.
Pingo: an isolated pond or pool, often with a rampart of upheaved soil around the perimeter,
caused by ice lens formation during periglacial conditions.
Psammophilous: species that has a specialised association with, or requirement for, sandy
substrates particularly bare sand and windblown sand.
Rendzina: highly calcareous poorly formed soil formed from raw chalk, marl, limestone or
calcareous drift.
Solifluction: soil movement, where waterlogged sediment flows slowly down-slope, over
impermeable material. It occurs in periglacial environments where melting during the warm season
leads to water saturation in the thawed surface material (active layer), that flows down-slope over
impermeable deeper frozen (permafrost). When the "flow" is due to frost heave that creates
undulating corrugation at right angles to the slope, then solifluction can result in striations or
periglacial stripes.
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Introduction
“Few of the lowland districts of England have more striking
individual characteristics than the area known as Breckland.
W.G. Clarke, 1925
The Breckland Region
Breckland is a bio-geographical region of Eastern England, covering 1,019 km2. The soils are
characteristically sandy, very freely draining and nutrient-poor. The region has low rainfall, in
common with much of East Anglia, while the climate is more semi-continental and experiences
greater extremes of temperature. Plant and animal species more commonly associated with steppe
or Mediterranean regions can be found in Breckland. This combination of drought-prone soil, low
rainfall and cold winters has strongly influenced human land-use. As a result, this dynamic
anthropogenic landscape has supported a distinctive and unique biodiversity unlike any other part
of Britain.
Since the arrival of agriculturalists approximately six thousand years ago, the region has had a
dynamic and changing history of land-use. This was historically characterised by large areas of
extensively grazed dry vegetation, including grass or heather dominated heath, areas of low
intensity agriculture and river valleys and fens. The farming of rabbits in large enclosed warrens
from the early Middle Ages and intensifying through the 16th-18th centuries transformed parts of
the landscape into mobile dune.
The Breckland region is often regarded as a ‘heathland region’, so a few words to clarify the various
meanings of this term will be helpful. The term ‘heath’ can refer to a form of land-use, where
livestock were grazed (often involving commoners’ rights on land owned by an estate) across areas
of low productivity vegetation growing on low fertility soils. In this sense, ‘heath’ is a place name
that relates to a form of land-use. The term has been widely used in the classification of plant
communities, where it most often relates to dwarf-shrub vegetation that includes Ericoid species
(heathers) growing on acidic soils. In this sense, dry lowland heathland developed with grazing
management on lowland mineral soils is distinct from either wet heath (in valley or raised mires) or
‘moorland’ heath, which developed in upland areas on organic soils in areas of higher rainfall. But
confusingly, the terms has also been used by ecologists to describe the characteristic low nutrient
grazed and disturbed processes that characterise these vegetation types, and thus grasslands
lacking heather species but that are droughted, nutrient poor, disturbed and heavily grazed may be
referred to as ‘grass-heaths’. Throughout this report we refer to grass-heath and heathland
interchangeably as describing vegetation, and ‘heaths’ as describing places in the landscape.
Since the scientific enquiry into natural history began, Breckland has long been recognised amongst
entomologists and botanists as a place where distinctive biodiversity could be found. Early natural
historians catalogued a range of distinct species that appeared to be restricted to this unusual
region, and were rarely or never encountered elsewhere in Britain. Collectors and natural historians
explored the warrens, heaths, track-ways and fallow arable fields of the region, making important
discoveries. But the importance of this wide range of shifting and dynamic landscape elements
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seems to have become lost from the consciousness of modern conservationists. More recently
Breckland has been regarded as one of England’s ‘lowland heathland regions’ (e.g. an area still
supporting concentrations of lowland heathland, among a suite of regions that includes Dorset, the
New Forest, the Weald, Surrey and Hampshire, and the Suffolk Sandlings). This perception of
Breckland as a heathland region has permeated through priorities, objectives and approaches to
conservation implementation. This has been further reinforced by designation of some
internationally important features classified as ‘heathland’ due to the presence of heather Calluna
vulgaris within the community, and this has not always led to management that is appropriate for
the conservation of priority biodiversity.
Breckland was first named by W.G. Clarke, after the profusion of fallow ‘brecks’ (intakes from
heathland that were converted to unintensive arable, often with long fallow rotations) that
dominated much of the landscape in the late 1800s and early 1900s after the virtual abandonment
of cereal farming. W. G. Clarke began describing the region’s natural history, archaeology and
landscape, in his contributions to the Transactions of the Norfolk and Norwich Naturalists Society,
culminating in 1925 with his book “In Breckland Wilds”. Clarke’s account has become a defining
vision of what Breckland once was a landscape of rabbits, warrens, sand-dune and shingle, grazed
heath and abandoned fields. However, it is important to recognise that the landscape Clarke
described in 1890-1925 was just one snapshot-in-time, of a landscape undergoing a particular
major transition, within a much longer history of upheaval and dynamic land-use change. Some
aspects of this are explored in the section below.
Dynamic Changes in Breckland
The rapid arrival of warm, dry conditions after the last ice age, allowed raw chalk and sandy soils to
be colonised by Mediterranean and steppe species. Although forest cover then developed, the
combination of immature mineral soils, drought and large numbers of red deer Cervus elaphus
along the fen margin (as indicated by archaeological remains) suggests forest cover in Breckland
may have been fairly open. Breckland was settled and cleared by arriving farmers during the
Neolithic, c. 6,000 years ago, and still retains post-glacial species requiring open conditions that
have disappeared from most of lowland Britain. Subsequent forest clearance, shifting cultivation
and stock grazing created more open habitats. A pattern of cereal cultivation and grazing continued
through the Bronze Age, Iron Age and Romano-British periods, and after Saxon Estates were
subsumed and redistributed by the arriving Normans, continued in varying forms until the late
1800s. In general, cereal cultivation was more prevalent in river valleys, with grazed commons and
heaths on the drier plateaus and interfluves. However, all aspects of the land use were dynamic,
and there have been changes and upheavals through time.
The type and intensity of domestic grazing have changed greatly through the centuries and in
recent times. The mixed livestock flocks and herds that grazed during the Neolithic, Bronze Age,
Iron Age and Romano-British periods included more cattle than in later periods, when the Medieval
economy increasingly focused on sheep and wool production. Cattle would have imposed a
different type of grazing to sheep. Sheep grazing declined from the 17th century (Postgate 1962).
For example approximately 2,200 sheep grazed Lakenheath Warren in the 13th century; by the late
1940s only 600 occasionally grazed and these were withdrawn in 1956 (Crompton and Sheail 1975).
Sheep flocks were already largely absent from the landscape later described by Clarke.
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Inland Dunes
The 1km wide dune and blow-out at
Lakenheath Warren, described by Alex
Watt, was levelled during WWII.
A small fragment of this dune system
remains at Wangford Warren, and other
fixed dunes survive at Icklingham Plains
and Foxhole Heath.
There is little mobile wind-blown
accumulating sand in remaining systems,
that are now fixed dune (lichen dune,
grass swards or sand sedge Carex
arenaria dominated vegetation).
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Sheep and other livestock kept the nutrient status of heathlands low. Cropping of hides, milk, wool
and dung transfer relocated nutrients in the system (Dean et al. 1975). Overnight folding of large
sheep flocks onto arable land allowed their dung to fertilise the poorer soils increasing crop yields.
The nutrients transferred from the sandy heaths to the arable were crucial to sustaining the fertility
of cropped land (Newman 2002). Sheep were selectively bred to hold their dung until folded at
night (Smith 1980). This practice depleted grass-heath soils and maintained the low nutrient
conditions required by the heathland assemblages now valued so highly. Sheep herds were driven
to-and-fro along track-ways; this would have dispersed plant seeds and propagules around the
landscape.
Although rabbits may have been kept locally by the Romans, they presumably died out in early
post-Roman times (Williamson 2007). Following their introduction to the UK by the Normans,
rabbits were restricted to warrens (essentially enclosed rabbit farms) managed across increasingly
large parts of the sandy uplands of Breckland from the 13th century through the middle and late
medieval periods (Sheail 1971; Bailey 1988). It was only after the rise of game and sporting estates,
which ruthlessly controlled predators that rabbits could spread and proliferate across the wider
landscape (Sheail 1971); the ubiquitous distribution of rabbits described by Clarke was not
representative of most of Breckland’s history. It is also important to realise that the high densities
of rabbits that so impressed early ecologists such as Ernest Farrow (Farrow 1915; 1917a; 1917b)
and Alex Watt (Watt, 1936; 1937; 1938; 1940) were just a fraction of earlier intense levels of rabbit
activity that would not be conceivable to modern ecologists (Crompton and Sheail 1975). For
example, during 1855-1862 an average of 28,886 rabbits were harvested annually from Thetford
Warren, at a sustainable cropping rate of 24 ha-1 yr-1 (Sheail 1972).
Cereal cultivation and fallows were key to Breckland
The Medieval open-field system and fold-course rotation produced large areas of fallow arable
every year, ideal for populations of Breckland plants and insects that need disturbed ground and
open conditions. It is likely that many species that are now rare and threatened in the modern
landscape were once common in the cereal and fallow fields, rather than on the heath. Sheep were
folded on uncropped fallows to improve the soil and after harvest were also folded on the rye and
barley stubbles. Fallows were an intimate part of the open field rotation that included more
frequently cropped infields, less intensively managed out-fields cultivated at intervals following
long fallow periods (Postgate 1962; Bailey 1989) and later a third element, the ‘brecks’. Brecks were
intakes of heathland converted to arable and cultivated for a few years before being left fallow for a
long period (Postgate 1973). Weedy fallows were widespread, for example in 1616, nearly two-
thirds of the arable land of Elveden was cultivated, while at Wangford in 1625, outfields were
cultivated only one year in three (Postgate 1962). The extent of cultivation versus fallow varied in
response to economic demand.
The pattern of cereal cultivation and grazed heath has been dynamic, with episodes of increase and
then decline. There have been losses and gains in the relative areas of cultivated cereal,
biodiversity-rich fallows and grazed heath.
At Grimes Graves and West Stow episodes of cultivation were followed by periods of
abandonment, suggesting the location of Bronze Age and early Saxon farmsteads shifted
location in the landscape, providing heterogeneity and variability.
15
Following the Black Death of the mid 1300s, there is evidence that some arable was
abandoned to heath (Bailey 1989).
When grain prices collapsed in the 15th century as much as 70% of the demense arable could
lie uncultivated in any one year (Bailey 1989).
During the 17th to 19th centuries at Icklingham, the relative locations of frequently cultivated
in-field and infrequently cultivated out-field at Icklingham shifted and changed (Postgate
(1962).
Brecks (ploughing of heathland for temporary fields) occurred during the 16th century, with
references to ‘breakes’ ‘breches’ and ‘brakes’ (Postgate 1962).
During the 18th and early 19th centuries, increased corn prices (e.g. during the Napoleonic
Wars) led to widespread heathland reclamation and large areas of ‘brake land’ (Postgate
1973). However it is unlikely that these brecks were ploughed more often than once in ten
years (Postgate 1973), suggesting a large increase in low nutrient fallows and broken
ground.
Sheail (1979) described ‘shifting cultivation’ in the 17th to 19th centuries whereby areas of
heath were broken up and cultivated, offset by reversion of exhausted arable into the
warren.
However, the common perception that all heathland in Breckland had experienced episodes of
arable cultivation and was subject to ‘shifting cultivation’ throughout history is incorrect. The
brecks and intakes of the 18th and 19th centuries were a more recent phenomena compared to the
relative stability of heaths through the Middle Ages (Postgate 1962; 1973). According to Postgate
(1962), little reclamation of heathland occurred in Breckland during the Middle Ages because of the
opposition to "plowing the lords hethe '' that prevailed under manorial custom. Some Medieval
heaths remained uncultivated up to the enclosures of the 1800s (Bailey 1989). Thus, although much
of the existing grass-heath resource was created from brecks abandoned in the late 19th or early
20th century (e.g. Thetford Heath, much of STANTA), some parts of surviving heaths may be ancient
and may not have been ploughed for at least 800 years.
The process of enclosure occurred more slowly and later in Breckland than elsewhere in East Anglia.
Agricultural improvement then accelerated in the 18th and 19th centuries, peaking during 1800-
1820, with enclosures, breaking up of ancient heaths, marling and soil improvement and conversion
to arable on an unprecedented scale. The overall area of grass-heath declined from over two-thirds
in the late 1600s, to approximately 30% by the 1830s (Sheail 1979). As part of the drive to crop the
windswept mobile sands, charismatic pine shelter belts were planted during 1815-20 that still give
the region a distinctive character.
However, results were patchy and some arable was abandoned from the early 1820s with the onset
of agricultural recession, which further intensified through the later 19th and early 20th centuries
with the collapse of grain and wool prices. From the late 19th century to the early 1900s, large areas
of former arable, including recent intakes, were abandoned creating sandy fallow brecks, while
rabbit farming or sporting becoming the main land-uses (Sheail 1979).
Between 1900 and 1934:
the overall area of grass-heath and heath increased from 28,932 ha 31,922 ha.
16
However, the net increase of 2,990 ha masks even greater dynamic change during 1900-34:
7,872 ha of heath was lost to arable and afforestation.
10,862 ha of grass-heath were created from arable reversion (Farrell 1993).
Crucially, the economic depression that provided so many brecks throughout Breckland, also led to
the loss of sheep grazing from the remaining heaths and so the landscape described by W.G. Clarke
was primarily influenced by rabbits rather than livestock.
Recommendation:
Further investigation of the long term patterns of land-use between heath and arable,
linking land-use archaeology and ecology, will benefit understanding of habitat and species
requirements.
Relating the current and recent past distribution of speciality Breckland vascular plants to
historical land-use will provide insights to past ecology.
Recent Landscape and Land-Use Change
The Land Utilisation Survey overseen by Dudley Stamp identified Breckland as an economically
marginal region, with low rental values and large areas of fallow arable fields (Stamp 1938). Along
with other marginal heathland regions, Breckland was therefore targeted for afforestation by the
government. From 1922 heaths and sandy brecks were planted and converted to forest, primarily
with pines and other conifers but also with stands of beech Fagus sylvatica and belts of other
deciduous trees (Skipper and Williamson 1997). Although disrupted by military training during the
Second World War, afforestation continued post-war and eventually one quarter of the region was
planted. The resulting Thetford Forest is the largest lowland conifer forest in the UK (Eycott et al.
2006).
In parallel with afforestation, large agricultural estates realised that introduction of new rotations
(involving lucerne, fodder crops and cattle), combined with newly available machinery, allowed
conversion of even the sandiest and most unproductive acidic Calluna-dominated heaths to
productive agriculture. With the twin pressures of afforestation and arable conversion, the
remaining resource of fallow breck and heath rapidly diminished. From the mid-20th century, arable
farming intensified. As elsewhere, the use of chemical fertilisers, pesticides, increase in winter
sowing and consequent reduction in over-winter stubbles, have had a significant effect on the
farmed landscape. However, it is notable that winter stubbles remain more prevalent in Breckland
than in regions of clay soils. The development of modern irrigation systems, dependent on
groundwater and river abstraction, has allowed the intensive cultivation of an array of high value
vegetable and salad crops, whilst outdoor pigs and novel crops such as herbs and even tulips, have
also joined the scene. Today, Breckland can be highly productive, with more variable cropping
patterns than the adjacent claylands. Other than where agri-environment schemes have
maintained specially managed areas, the fallow ‘breck’ has now completely disappeared from the
landscape.
17
The area of grass-heath declined by 76% within the 20th century:
1900: 28,932 ha
1934: 31,922 ha
1950: 9,268 ha
1980: 4,529 ha 1
1990s: c 7,000 ha 2
1 estimated by Farrell (1993)
2 the Natural England Natural Area Profile estimate of grass-heath extent is 2,471 ha greater,
as it also includes more recent reverted arable within STANTA in the estimate of the current
resource.
Changes in Fen, Wetland and River Valley habitats
Fens were once extensive along the Breckland/Fenland boundary but have been almost entirely
destroyed. Mosaics of species-rich fen meadow and wet grassland survive at Pashford Poors Fen
and Lakenheath Poors Fen, for example, but these are small fragments of formerly extensive fen
and wet grassland reclaimed prior to the 1940s. Reclamation of further areas on the fen edge
occurred with the Great Ouse Flood Protection Scheme post-1950s (Rothera 1989). Remaining sites
are detrimentally affected by adjacent drainage and are vulnerable to groundwater abstraction
(Rothera 1998).
The spring-fed valley fens have been vulnerable to drainage on adjacent farmland, subsequent
drying out and scrub invasion. Abandonment of traditional grazing, and/or cutting of reed, saw
sedge and peat fuel during the 20th century led to willow and alder scrub invasion and a loss of
wildlife value in remaining Breckland fens (Rothera 1989). Pingos, the relict peri-glacial waterbodies
that hold important fen and invertebrate communities, occur at high densities within Breckland
(Walmsley 2008), but have suffered loss through agricultural improvement and afforestation. The
remaining pingo sites have also been subject to scrubbing up and succession to woodland, with
resulting shading and organic mud accumulation from leaf litter as a result of a lack of grazing after
the 1940s (Rothera 1998).
The rivers of Breckland and their adjacent wetlands have experienced substantial change and
modification. Channel engineering works altered the course and profiles of rivers from the 17th
Century through to the 1970s (Rothera 1998). Reclamation for agriculture and subsequent
improvements led to a substantial loss of adjacent wetlands, such as wet grassland and fen,
especially along the shallower valleys of the Wissey and the Lark (Rothera 1998). However, some
river valley wetlands have survived, with concentrations of County Wildlife Sites on the Little Ouse
downstream of Brandon and on the Lark near Cavenham, for example. However, these are often
much altered, being drier, more fragmented and less species rich than a century ago. W G Clarke
described redshank and snipe in nesting wet meadows, but these are now absent from Breckland as
breeding species.
As with the spring-fed fens, the abandonment of traditional uses of riverside resources has led to
the development of sallow car and wet woodland. The planting of poplar in Thetford Forest along
the Little Ouse has altered the character of the riverside fenlands. However, as these plantations
are abandoned and decay a rich mix of open fen, carr and standing dead wood is developing. A
more intact series of riverside habitats has been preserved along the Wissey in STANTA.
18
The damming of rivers has created areas of open water, such as Stanford Water on the Wissey and
Thompson Water on a tributary of the Wissey, whilst modern gravel extraction has created new
wetlands in place of more typical river valley habitats at Lackford, Lynford and south of Thetford.
19
Pingos
Pingos are ground water fed pools
created from the thawing of peri-
glacial ice-lenses.
Pingo sites are a key feature of
Breckland and support important
communities of aquatic invertebrates
including Heteroptera and Coleoptera.
20
Breckland Meres
The Devils Punchbowl
May 2007
November 2008
September 2009
June 2010
Breckland Meres are ground-water fed fluctuating water bodies, with percolation of
ground-water through a semi-permeable base lagging behind groundwater recharge from
winter rainfall. Successive flooding and draw-down results in concentric zoning of
vegetation. Pictured: The Devils Punchbowl in four successive years © N. Armour-Chelu
(2007-09) & T. Pankhurst 2010
Recently flooded margin
© T. Pankhurst
Grazed meres support rare and distinctive species associated with re-flooding of droughted
sediments, such as the two-spined seed shrimp Cypris bispinosa, a Mediteranean species that
occurs episodically in some Breckland Meres.
21
Breckland Conservation and the Need for this Audit
The afforestation of Breckland and the loss of heathland was decried in the mid 1930s by the
Norfolk Naturalists Trust and notable figures such as the biologist E.J. Salisbury and geographer L.D.
Stamp, who campaigned to preserve some of the wild landscape to protect its character and
biodiversity. Their bold vision for a connected network spanning from STANTA in the north in a
broad sweep of landscape joining remaining heaths in the east and south of Breckland (Sheail 1979)
was never realised. However, a number of key sites were secured for conservation in perpetuity,
beginning with the acquisition of East Wretham Heath by the Norfolk Naturalists Trust (now Norfolk
Wildlife Trust) in 1939, closely followed by Weeting Heath and Thetford Heath (purchased for the
Norfolk Wildlife Trust by the philanthropist and conservationist Christopher Cadbury), in 1942 and
1949 respectively. Supported by a legislative framework, nature conservation (the National Parks
and Access to the Countryside Act 1949) came into being, the Nature Conservancy and its successor
agencies (the Nature Conservancy Council, English Nature and most recently Natural England)
designated a suite of key sites and secured their protection (see Table 4).
The national and international importance of Breckland has been recognised by the designation of
four National Nature Reserves (NNR) and 55 Sites of Special Scientific Interest (SSSI) that cover 40%
of the land area. Of these more than 30 are heaths or contain a substantial heathland element. The
designation of many of these sites in the 1950s and 1960s coincided with a period of rapid and
profound ecological change on most heathland sites.
The loss of livestock grazing, a consequence of the dominance in the farming economy of arable
cropping, elevated the importance of rabbits in grazing the vegetation and preventing succession.
The selective grazing and small-scale scraping and disturbance created by rabbits were crucial in
controlling both the plant species composition and the physical structure of the vegetation and thus
the range of micro-habitats available for invertebrates and plants (Farrow 1917a; Watt 1957; 1960;
1962; 1981a; 1981b; Rodwell 1992). Following the introduction of myxomatosis to the UK in 1953
and the translocation and release of infected animals by farmers seeking to control rabbits in the
agricultural landscape, the rabbit populations had collapsed by 1955. The effects on both
vegetation and invertebrates were immediate and profound. Many heaths became grassy,
overgrown and subject to scrub and pine invasion (e.g. Marrs Hicks and Fuller 1986) and it is likely
that some species and population extinctions can be directly attributed to these. In addition, the
harvesting of heath products such as gorse, bracken and heather had also ceased during the early
20th century, allowing further invasive change to occur (Crompton and Sheail 1975; Rothera 1998).
Conservation efforts have been successful in restoring grazing management regimes to the majority
of heathland SSSIs. At some sites rabbit populations rapidly recovered (e.g. Weeting Heath NNR);
however, the destruction of rabbit populations on some key heathland sites following their
recovery hindered conservation interests. STANTA has been sheep grazed since before the 1970s,
while at some privately managed sites sheep grazing was introduced during the 1970s (e.g.
Thetford Heath NNR). Establishment of grazing regimes was greatly helped by the introduction of
agri-environment support mechanisms. In 1988 the Breckland Environmentally Sensitive Area (ESA)
scheme was established, providing area payments to landowners to graze heathland, combined
with capital payments for grazing infrastructure such as fencing and control of scrub and bracken.
The ESA scheme was closed to new applications in 2004 and has been followed by the introduction
of Environmental Stewardship (ES) in 2005, providing a similar range of incentives with generally
22
enhanced payment rates. Under the Breckland ESA, all the major heathland areas have been fenced,
grazed and managed (Perkin and Norden 2007).
However, at some key sites such as Lakenheath Warren, the eventual restoration of grazing only
occurred after a period without grazing that spanned many decades. During this time dense
grassland, bracken, scrub and woodland cover dominated, with resulting effects on soil conditions.
Grazing, at least by livestock, is still absent from some heathland SSSIs, including Barnham Cross
Common, Maidscross Hill and, perhaps unsurprisingly, Thetford Golf Course.
Heathland restoration has been further helped by initiatives such as English Nature’s Tomorrow’s
Heathland Heritage programme (2000-2005, with support from the Heritage Lottery Fund, HLF). A
significant project was the creation of 300ha of predominantly grass-heath within Thetford Forest, a
project which continues now as the Brecks Heaths Project, a partnership of NWT, FC and NE.
Norfolk Wildlife Trust’s own HLF-funded project, Securing the Future, supported habitat restoration
on the Trust’s heathland and wetland nature reserves in Breckland.
However, the period of vegetation succession that most sites experienced prior to the restoration
of grazing regimes had important consequences, as follows:
In respect of local populations of species requiring open conditions or bare ground, it is not
clear what has been lost during the period when heaths were unmanaged and developed
closed vegetation.
It is not clear how readily scarce invertebrates have been able to re-colonise sites following
the restoration of management.
Accumulation of organic matter into upper layers of soil may have persistent and long-
lasting effects on nutrient availability, vegetation composition, plant communities, rates of
succession and the rapidity with which vegetation and grass mats recover and close
following minor disturbance.
The importance of physical disturbance to grass-heath species was recognised by ecologists such as
Alex Watt. At a small number of SSSIs, soil disturbance was initiated in 1960 following myxomatosis
(Dolman and Sutherland 1992), but primarily to provide nesting opportunities for stone curlew, and
also as firebreaks, rather than as part of a wider understanding of ecological management. After
the recovery of rabbit populations at Weeting and Thetford Heaths, for instance, rotovation
treatments were discontinued, and the existence of these managed plots was largely forgotten.
Examination of the vegetation developed on these previously rotovated plots in the late 1980s,
combined with monitoring cultivation treatments in a replicated blocked experiment, confirmed
the importance of physical disturbance to maintaining the open, lichen-rich conditions on which
many characteristic species depend (Dolman and Sutherland 1991; 1992; 1994). Subsequent
conservation management at some key sites has included practices such as rotovation and turf
stripping. However, across most sites, the area of physical disturbance treatment has remained
minimal, with sheep grazing (and occasionally cattle or ponies) considered the key tool for
conservation.
Internationally important habitats within Breckland have been designated with the Breckland SAC
(Special Area of Conservation; see Conservation Resource section). Designation in 2000 of the
Breckland SPA (Special Protection Area; see Conservation Resource section) for populations of
breeding stone curlew Burhinus oedicnemus, woodlark Lullula arborea and nightjar Caprimulgus
europaeus coincided with the designation of the Breckland Farmland SSSI and the Breckland Forest
23
SSSI. The Breckland Forest SSSI citation also notes important vascular plant and invertebrate
assemblages.
Conservation success includes the reversal of decline in the Breckland SPA population of stone
curlew with a doubling of the Breckland population and the BAP species target, to contribute 125
breeding pairs by 2000 and 180 by 2010, was met and surpassed ahead of schedule with 230 pairs
in 2009 (Tim Cowan pers. comm.).
However, this has largely been achieved by labour intensive intervention on arable land, including
nest location and protection through effective liaison with farmers and land managers. This is not
sustainable in the long term and restoration of suitable conditions across semi-natural grass-heaths
to support a larger proportion of the population, together with initiatives to increase the area of
safe nesting habitat on arable land, is a high priority by both the RSPB and Natural England.
The technical challenges of the large scale restoration and management of Breckland’s wetlands
(especially pingo sites) are great, but within the last 15 years new techniques have facilitated
extensive restoration works at Norfolk Wildlife Trust’s Thompson Common. Similar work has also
recently been undertaken at Cranberry Rough, Hockham, clearing carr to re-establish fen alongside
wet woodland, with the introduction of an extensive grazing regime encompassing this and
adjacent pingos. Pingo restoration work has also been undertaken on the STANTA and on Foulden
Common, and an increasing number of pingo sites (both SSSI and County Wildlife Sites) are now
being managed under Environmental Stewardship. Under the Breckland ESA scheme over 2000 ha
of river valley grassland and associated wetland habitats have been managed under sympathetic
management regimes, and a further 320 ha re-created from arable land. Some of this has only
modest value for nature conservation (with the landscape value of these grasslands sometimes the
main rationale), but opportunities exist under Environmental Stewardship to enhance and extend
this (with increased payments and improved targeting), with benefits for wetland plants,
invertebrates and birds.
The extinct pool frog Rana lessonae (a Breckland specialist, extinct in the UK since the 1990s) has
been reintroduced to one pingo site. Early indications to date are that this has been successful,
forming a self-sustaining population without need for reinforcement.
Current concerns for Breckland’s Biodiversity
Despite conservation successes, there are major concerns.
In developing the Breckland Natural Area profile, Stephen Rothera produced the most
comprehensive collation and synthesis to date of information on the species present within
Breckland (Rothera 1989). Although the numbers of RDB, BAP and Breckland speciality species
associated with each habitat were given, and examples listed, the numbers identified can now be
seen to be incomplete and out-dated following revision of the BAP species lists in 2007. The Natural
Area profile did not aim to provide guidance on the ecological requirements or conservation
management of priority species. The need remains, so that evidence based prescriptions can be
formulated and delivered.
24
Most crucially, land managers lacked a comprehensive evidence base on which conservation
prescriptions and management could be based. Particular issues were the following:
There was insufficient knowledge of what species occur in Breckland.
The ecological requirements and management techniques to sustain most Breckland
conservation priority species were not readily available to conservation advisers or land
managers.
Objectives and priorities for conservation management were incomplete and often poorly
defined.
A workshop to take stock of progress and challenges in conservation in Breckland (Davy 1995)
identified the need to:
Analyse habitat requirements, trends and distribution of key biodiversity.
Identify which species are indicators of Breckland.
Determine how the management of one species affects others.
Look at the habitat requirements of key species.
Assess the present status of rare plants and animals in Breckland.
Fifteen years later progress on most of these priorities has been very limited. Notably, the
workshop recognised the strong potential for an approach based on collating and pooling the
valuable knowledge available but scattered among practitioners and local experts:
“no shortage of volunteers with good knowledge but that there is a great need for them to
be properly co-ordinated”
“need to co-ordinate, but also for people to send their data in”.
In 2007 the Suffolk and Norfolk Biodiversity Partnerships brought together nearly 40 participants to
review progress for conservation in Breckland (Perkin and Norden 2007). For grass-heaths, the
workshop noted that:
Broken turf grasslands continue to decline.
Heaths are much “grassier” than they used to be.
There has been insufficient research and monitoring.
Also highlighted at the workshop was the plight of specialist Breckland species, both plants and
invertebrates, which require cultivated and ungrazed situations. The uncropped wildlife strips
(cultivated arable margins), established under the Breckland ESA, were suggested as an important
mechanism for managing these species, but it was noted that research and survey in this area had
been limited (B. Nichols, pers. comm.).
The workshop (Perkin and Norden 2007) recommend that strategic action include:
Greater sharing of information and a more coordinated and prioritised approach to
conservation action in the Brecks.
The preparation of a Brecks management plan and Brecks BAP as an integral component of the
proposed management plan.
An initial assessment of the presence or absence in the Brecks of the new priority BAP species
and habitats included in the revised national BAP list.
A detailed planning and feasibility study on the creation of an ecological network in the Brecks,
to build on the ecological networks studies undertaken in Norfolk and Suffolk.
25
The Breckland Biodiversity Audit has set out to address many of these needs and to provide an
understanding of the priority species in Breckland, their requirements, and strategic approaches to
management for their conservation.
Aims of the audit
The Breckland Biodiversity Audit was commissioned and guided by a wide partnership of
organisations that included the Biodiversity Partnerships of Norfolk and Suffolk, the Brecks
Partnership, the Forestry Commission, Natural England and Plantlife. It seeks to provide a robust
evidence base to guide actions to secure Breckland’s biodiversity for the future.
The aims of the Breckland Biodiversity Audit may be summarised as three key elements:
What, Where and How.
1) What is the biodiversity in Breckland?
The audit:
Collated and examined available evidence to understand what species are present in
Breckland.
Objectively defined the suite of Breckland conservation priority species.
Where possible, assessed the recent or current status of priority species, although the
evidence base for this was expected to be highly incomplete.
2) Where is this biodiversity?
In order to support strategic biodiversity delivery at a landscape scale, we undertook to:
Map the density of BAP species across the region
Map the density of range restricted regional specialists
Map assemblages requiring particular ecological conditions and processes, in order to
identify hotspots and spatial priorities for different groups
Assess the quality of evidence and gaps in the knowledge base, for both species
distributions and status, and provide recommendations for further survey requirements.
3) What does the priority biodiversity require? (How can it be conserved?)
A key objective of the Breckland Biodiversity Audit was to provide land managers and conservation
advisers with guidance as to how to enhance and sustain the important biodiversity. Effective
management is best achieved by providing prescriptions based on sound evidence rather than on
myth, hearsay, received wisdom or dogma. The novel approach taken here was to identify multi-
species assemblages and associated flagship invertebrate and plant species, requiring similar
ecological processes and conditions (here-after referred to as ‘assemblages’ or ‘guilds’). This has the
aim of integrating prescriptions for multiple species into habitat-based approaches, but through an
evidence-based approach rooted in an understanding of the ecological requirements of individual
species.
26
The steps taken in this process were to:
Collate and objectively analyse documentary evidence and expert knowledge for numerous
Breckland conservation priority species from across a wide range of taxonomic groups.
Compile management experience and relate this to the ecological requirements of
assemblages.
Provide explicit management guidance for each of the different groups of species.
Identify gaps in relation to the evidence base, in terms of understanding distributions,
requirements, and responses to management.
And thus to provide recommendations for research and experimental work required to
support the evidence base for management.
27
The Breckland bio-geographic region: climate, soil, vegetation and regional limits
The unique and distinctive character of the Breckland bio-geographical region results from the
interplay between its characteristically low nutrient, free-draining soils and its slightly drier climate
relative to most of southern England, plus the influence of both of these on human land-use and
vegetation.
The Breckland National Character Area (NCA) 1 covers just 1019 km2, just of the land area of the UK.
It lies in a gap in the chalk escarpment between Newmarket to the south and Swaffham to the
north (Figure 1). The peat and silt Fens border Breckland to the west and the clayland plateau of the
East Anglia Plains lies to the north-east, east and south. Breckland drains westward via three main
rivers, the Little Ouse, Wissey and Lark, into the fens. The river valley floodplains are flanked by
gravel terraces. The interfluves between these, consists of gently undulating high ground mostly of
20 50 meters altitude, dissected by broad dry valleys.
Regional boundaries
The boundaries of Breckland are not clearly defined. The transition from the Breckland sands to the
peats and silt fen soils at the edge of the Fens can be fairly abrupt. However, elsewhere the
Breckland landscape gradually gives way to rolling chalk farmland to the south and a gradual
transition into less extreme soils and land use to the north and east. For this reason, different
authorities have offered various definitions of the extent and limits of the region. Throughout this
study we adopt the latest of these, the Breckland National Character Area, which coincides with the
earlier Natural Area (NA) as defined by Natural England. The Natural Area was primarily defined by
the mapped extent of sandy soil-series, characteristic of Breckland (Figure 3) and thus has a clear
ecological basis. In contrast, the boundaries of the earlier Breckland ESA were influenced by easily
mapped boundaries, such as roads and rivers. Whilst almost all of the ESA is encompassed within
the NCA, there are some discrepancies between the boundaries, particularly to the north and the
west (Figure 2). A handful of Sites of Special Scientific Interest (SSSI) are fully excluded by one or
both definitions of Breckland (Appendix 1). For example, pingos at East Harling Common and
wetland at Castle Acre Common are included within the NCA but not the ESA. Six hectares of
Thompson Water, Carr and Common fall outside the ESA boundary and small parts of the Breckland
Farmland SSSI (notified in 2000, under the 1981 Act for the internationally important population of
stone curlew Burhinus oedicnemus as a prelude to proposing the Breckland Special Protection Area)
lie outside both boundary systems. Lakenheath Poors Fen, comprising damp calcareous grassland,
neutral grassland and fen meadow, is regarded as a transitional site between Breckland sands and
the Fens basin (Rothera, 1998). It is important as a remaining fragment of a previously extensive
tract of similar habitat lost to arable cultivation. However, the site is not included in either the NCA
or the ESA. However, it is important to recognise that that the boundaries of the NCAs are not
precise and that many of the boundaries should be considered as broad zones of transition.
1 Under a Natural England initiative, England has been divided into 159 areas with similar landscape character, which
are called National Character Areas (NCAs); previously known as Joint Character Areas (JCAs). The NCAs are a widely
recognised national spatial framework, used for a range of applications.
28
Climate
Breckland has long been known for a climate that is less oceanic than of the rest of the UK.
Breckland is drier, colder in winter and has more days with air frosts in all seasons than south-
eastern and central southern England (Table 1). Breckland also has lower minimum temperatures in
all seasons and a greater number of frosts in all seasons compared to both Cambridge and to East
Anglia. Breckland, however, is not drier than Cambridge or the wider East Anglian region (Table 1).
Table 1. Climate in south-eastern and central southern England, East Anglia, Cambridge and Breckland
(Santon Downham) for the period of 1979-2008.
SE & CS England
Winter
Spring
Summer
Autumn
Annual
Mean annual total rainfall (mm)
217.4
165.5
164.0
236.0
784.4
Mean minimum daily temperature (°C)
1.8
4.9
11.5
7.2
Mean maximum daily temperature (°C)
7.8
13.4
21.1
14.7
Mean number of days of air frost per season
30
10
0
7
46
East Anglia
Mean annual total rainfall (mm)
149.5
131.8
161.3
172.6
612.5
Mean minimum daily temperature (°C)
1.1
4.2
11.0
6.6
Mean maximum daily temperature (°C)
6.8
13.0
20.8
14.2
Mean number of days of air frost per season
30
10
0
6
45
Cambridge
Mean annual total rainfall (mm)
130.1
132.3
146.8
161.8
571.1
Mean minimum daily temperature (°C)
1.6
4.8
11.5
7.4
Mean maximum daily temperature (°C)
7.5
13.5
21.6
14.8
Mean number of days of air frost per season
28
8
0
5
42
Breckland (Santon Downham)
Mean annual total rainfall (mm)
158.6
149.4
176.6
179.0
663.7
Mean minimum daily temperature (°C)
0.4
3.2
9.9
5.4
Mean maximum daily temperature (°C)
7.6
13.6
21.3
14.8
Mean number of days of air frost per season
40
22
1
15
78
Source of data: Cambridge http://www.metoffice.gov.uk/climate/uk/stationdata; SE & CS England and East Anglia
http://www.metoffice.gov.uk/climate/uk/datasets; Breckland http://badc.nerc.ac.uk/home/index.html).
Geology, hydrology, soils and vegetation
The bedrock lying beneath Breckland is cretaceous chalk. This is overlain by chalk-sand ‘drift’ and in
some places, by chalky ‘boulder clay’, most likely deposited by extensive ice sheets during the
penultimate glaciation some 350,000 130,000 years ago. The drift comprises fractured lumps of
chalk, set in a mixture of chalk and sand. The clay content is generally less than 5%, but can be
locally higher particularly in the east of Breckland (Figure 3; Corbett, 1973). During the subsequent
interglacial, the drift was weathered and leached, and then during the last glaciation was
reorganised by peri-glacial frost heave in the prevailing tundra conditions. This resulted in stripes or
29
polygons of alternating calcareous ridges and deeper more acidic sand. Surface layers of wind-
blown sand have also been deposited. The resulting soils are extremely complex and varied.
The predominant soil types are sandy highly drained and drought prone and low in mineral clay or
organic content and thus potentially very infertile and low in nutrients.
Calcareous sandy soils and even shallower chalky rendzinas derived from the chalk-sand drift, cover
37% of the Breckland National Character Area (Table 2). These tend to occur on slopes where the
overlying weathered material has been removed by solifluction. Deeper, well-drained and leached
soils that range from less calcareous to highly acidic, cover a further 41% of Breckland. These tend
to occur on plateaus and range from sand over gravel, stony sand or strongly acidic podzols. Gravel
deposits cover some high level plateaus, up to 7 metres in depth, and other gravels occur in valley
terraces and valley head deposits. Localised areas of loamy soils occur in the peripheral areas of
Breckland (Figure 3) but are less droughty and nutrient poor, with dry loams, and damp loams and
clay soils, covering 5% and 4% of Breckland respectively.
Where vegetation is grazed and not annually cultivated, a range of grass-heath vegetation develops
on these sandy soils. Different plant communities are recognised on the chalky or on the acidic
sands. The relationship between soil type and the species composition of a spectrum of grass-heath
vegetation, from lichen rich vegetation on raw chalk soil through chalk turf to acidiphilous
grassland, was initially described by Alex Watt (1940). These grassland types were later re-classified
as part of the National Vegetation Classification (Rodwell, 1991; 1992) (see Table 3).
However, although the extremes may be distinct, the species composition of these plant
assemblages merges and intergrades along a gradient of pH and soil development from rendzinas
to podzols. While some management units may be dominated by one or other type of grassland,
these assemblages can also occur in intimate and complex mosaics at many sites. This range of
calcareous grassland, acidiphilous grasslands and lowland heath assemblages all share common
ecological characteristics, they are:
droughted, stress tolerant vegetation.
developed on dry mineral sands that are low in nutrients, particularly nitrogen (Davy and
Bishop 1984).
For this reason they are all treated as variants of “grass-heath” vegetation (following Watt 1940;
Dolman and Sutherland 1992; Rothera 1998). For the purposes of this audit, and particular in
making management recommendations, we most often generalise across these acidic and
calcareous vegetation types.
Wetlands, fens, fluctuating water bodies and pingos
Elsewhere in the landscape, where drainage is impeded, gleys and peats have formed, covering 12%
and 1.4% of the Breckland National Character Area respectively (Table 2). At the periphery of
floodplains, or in the lower reaches of dry valleys adjacent to the fens, seasonal water tables can
lead to impeded drainage and the development of gley soils formed under anaerobic conditions. On
the lowest ground where the water table is permanently at or near the surface, the sands and
gravels are covered by anaerobic peaty and humose gleys. Gleys can support mesic vegetation
30
influenced by seasonal water tables and damp grassland, while undrained intact peat can support
fen communities.
In the headwaters and tributaries of the Little Ouse, Lark, Wissey and Thet spring-fed valley-head
fens have developed on chalky nutrient poor water that percolates upward through thin peat layers
(Rothera 1989). Fen exists in a number of sites including at Great Cressingham Fen, Thompson
Common and Gooderstone Fen in Norfolk and Market Weston Fen in Suffolk which also has saw
sedge Cladium mariscus, as does Hopton Fen nearby. Fen with saw sedge Cladium mariscus also
exists at Talent’s Fen on Foulden Common and at Swangey Fen on the edge of the National
Character Area.
Organic peat occurs over most of the river valley floodplains, reaching 2-3 metres depth in the
centre of larger valleys, but is generally drained and humified to a eutrophic state (Corbett, 1973).
Little of the valley fen resource remains, though areas do exist along the River Little Ouse between
Thetford, Brandon and Weeting and in fragments elsewhere.
Peats have also formed locally in meres (Corbett 1973) fluctuating ground-water fed water bodies
on the plateaus, all restricted to the Norfolk Breckland. These unusual hydro-geological features are
fed by base-rich groundwater with no in-flow or out-flow streams and exhibit concentric zones of
different vegetation due to fluctuation in the water table. Importantly, they are thought to be
naturally self sustaining, not silting up or filling in, as vegetation is killed off by drying and re-
flooding (Rothera 1989). There are five principal meres which are recognised as true fluctuating
ground-water fed meres, these are: Langmere, and Ringmere (both at East Wretham Heath),
Fowlmere, Home Mere (in STANTA at Thorpe Great Heath) and the Devil’s Punchbowl. There are 3
other meres within STANTA which demonstrate some characteristics of fluctuating meres -
Smoker's Hole, West Mere and West Tofts Mere. Of these, Smoker's Hole is the most like the
principal five, the other two are less typical, West Mere may have with underlying impermeable
strata, whilst West Tofts is spring-fed), but which nevertheless exhibit a response to high water
tables in the surrounding chalk/sands. The identification of remaining meres is less certain but
essentially comprises a series of hollows around the East Wretham/Roudham area, which clearly
have the same form as the principal meres but that hold water only occasionally when the water
table is particularly high. There are at least seven of these on East Wretham Heath and a further 8
through the Roudham Forest block to the east of East Wretham Heath (B. Nichols pers. comm.).
Some water bodies near Larling have also been suggested to exhibit fluctuating mere characteristics
(Watson, 1974). A number of other waterbodies exist that are rain-fed and lack the characteristic
species of fluctuating meres.
Pingo systems, created by ice lenses during tundra conditions c20, 000 years ago, comprise
complexes of pools. Within one system, different pools may vary in the extent to which they are
ground water fed, their pH, whether water levels fluctuate and in their vegetation. This provides
complex range of ecological conditions. Surviving systems occur at Thompson Common, Foulden
Common, East Harling Common, Great Hockham (Hills and Holes), Breckles Heath and Frosts
Common and within STANTA (Rothera 1989; Walmsley 2008).
The floristic diversity and interest of the pingo systems arises from variations in substrate,
hydrology, water pH and the resulting habitat mosaic (Walmsley 2008). Where water levels within
the hollows fluctuate, vegetation may be unable to establish for long periods and bare mud on the
draw-down zones can provide opportunities for species that need low levels of competition. High
31
quality calcareous fen communities may develop in peat-filled basins fed by calcareous springs, or
ponds which drain down to damp mud during the summer months (Walmsley 2008).
The exceptional invertebrate fauna, which includes numerous RDB species as well as Breckland
specialities, is attributed to the stability of these habitats over very long periods, as well as the large
diversity in habitats (Foster 1993; Lambley, 2005). Foster (1993) observed that: ‘the remnants of
early postglacial biota’ probably persist because they are often still fed by the same groundwater
source that created them. Snail-killing flies are an outstanding feature at many pingo sites,
particularly Thompson Common, which supports a large proportion of the national fauna (Walmsley
2008).
32
Figure 1. a) Map showing the location of Breckland within England and within the counties of Norfolk,
Suffolk and Cambridgeshire, b) Location and boundary of the Breckland National Character Area (NCA),
showing urban centres, major roads and forest cover
33
Figure 2. The extent of Breckland, showing the limits of the Breckland National Character Area and
Breckland Environmentally Sensitive Area overlain on Ordnance Survey 10km squares. The Breckland
buffer is the widest extent of the combined area of the NCA and ESA, buffered by 1 km, and was used for
selection of the Breckland 10 km squares
34
Table 2. Soils occurring within the Breckland Natural Character Area (Figure 3) showing the area and
percentage of the NCA covered by aggregate types. Soil series and horizon data obtained under licence
from NATMAP, National Soil Resources Institute, Cranfield University, with soil classification also informed
by Corbett (1973)
Major Soil Group
Soil Series
Description
Area (km2)
Area km2
(%)
Calcareous soils
Newmarket 1 & 2
Dry chalky Rendzina
252.3
376.3
(37 %)
Methwold
Deep well drained chalky sand
124.0
Well drained sandy soils
(non-calcareous to
acidic)
Worlington
Deep well drained, acidic sand
or stony sand
268.8
415.5
(41 %)
Newport 2, 3 & 4
Deep well drained coarse sand
146.7
Dry loamy soils
Swaffham Prior
& Moulton
Well drained chalky loam
46.1
48.6
(4.8 %)
Reach
Shallow humose chalky loam
2.0
Barrow & Melford
Dry loamy sandy-clay
0.5
Damp loamy or clay soils
Burlingham 1 & 3
Damp deep loam
14.4
39.8
(3.9 %)
Ollerton
Damp deep sandy loam
9.0
Ashley
Damp deep loam to clay
15.9
Hanslope
Damp deep calcareous clay
0.5
Gleys:
seasonally wet poorly
drained organic or clay
soils
Isleham 2
Poorly drained seasonally wet
gleyed deep humose sand
107.4
122.6
(12 %)
Thames
Poorly drained seasonally wet
gleyed deep calcareous clay
1.0
Wickham 2
Seasonally wet humose silty
clay
5.4
Beccles 1 & 2
Seasonally wet deep loamy
clay
8.8
Fen peat
Adventurers 1 & 2
Fen peat, mostly drained and
oxidised
14.6
14.6
(1.4%)
Open Water
1.7
1.7
Total area:
1019
35
Table 3. Grass-heath vegetation in Breckland classified in relation to the National Vegetation Classification
(Rodwell, 1991; 1992), also showing closely related grassland communities
Chalk grassland in slightly mesic/temperate sites
CG2 Festuca ovina-Avenula
pratensis grassland
Short-grazed, species-rich calcareous grassland characteristic of free-
draining calcareous soils with temperate (relatively warm and dry)
lowland climate. Compared to xeric oligotrophic CG7 (below), CG2 is a
widespread community of lowland grazed chalk grassland (e.g. North
and South Downs, Chilterns to Lincolnshire and Yorkshire Wolds).
Calcareous Grass-heath (Watt’s grasslands A and B)
CG7 Festuca ovina-Hieracium
pilosella-Thymus praecox /
pulegoides grassland
Chalk grassland characteristic of thin stony very free-draining and
highly oligotrophic calcareous soils developed in more continental
climatic conditions, with heavy grazing and occasional disturbance.
CG7a Koeleria macrantha sub-
community
Grassier and herb rich sub-community
CG7b Cladonia spp. sub-
community
Cladonia-rich calcareous grass-heath characteristic of Breckland, found
elsewhere in UK at Porton Down in Salisbury Plain (Avenula pratensis
can increase in dominance in absence of grazing).
CG7c Ditrichum flexicaule-
Diploschistes scruposus sub-
community
Rare community confined to Breckland, with crustose lichens on firm
calcareous substrate, especially on exhausted arable soils, rabbit
warrens, turf stripped areas or mounds of chalk rubble
CG7d Fragaria vesca-Erigeron
acer sub-community
Grassier grass-heath that can occur on abandoned arable, Festuca
rubra may replace F. ovina.
CG7e Medicago lupulina
Rumex acetosa sub-community
Grassier sub-community
Acidiphilous Grassland (Watt’s grasslands D-G)
U1 Festuca ovina-Agrostis capillaris-Rumex acetosella grassland
U1b typical sub-community
Associated with lighter grazing
U1a Cornicularia aculeata-
Cladonia arbuscula sub-
community
Pioneer or established lichen heath sub-community, on recently
colonised ground, also associated with heavier grazing; community
considered by Rodwell as largely restricted to Breckland within UK
U1c Erodium cicutarium-
Teesdalia nudicaulis sub-
community
Winter annual sub-community, associated with surface disturbance;
community considered by Rodwell as largely restricted to Breckland
within UK and contains characteristic steppe species including
Breckland specialists
U1d Anthoxanthum odoratum-
Lotus corniculatus sub-
community
Transitional towards calcareous CG7 grass-heath
U1e Galium saxatile Potentilla
erecta sub-community
Occurs on more mesic soils; transitional to U2a Deschampsia flexuosa
grassland
Fixed dune communities
SD8 Festuca rubra-Galium verum
fixed dune grassland
Fixed dune grassland, on windblown sand or former arable
SD10 Carex arenaria dune
community
Carex arenaria (sand sedge) dominated vegetation on stabilised blown
sand
SD12 Carex arenaria - Festuca
ovina - Agrostis capillaris dune
grassland
Mossy fixed dune grassland
Transitions to dwarf-shrub heathland
H1 Calluna vulgaris - Festuca
ovina heath
Intergrades with U1 grassland depending on intensity of grazing and
disturbance history
Transitions to Deschampsia dominated grassland depending on nutrient status and management
U2a Deschampsia flexuosa
grassland; Festuca ovina-Agrostis
capillaris sub-community
Not described by Watt, may be occurring increasingly in Breckland as a
result of nitrogen enrichment and organic matter accumulation
36
Figure 3. Distribution of soil types in the Breckland Natural Character Area and surrounding region. Soil
series and horizon data obtained under licence from NATMAP, National Soil Resources Institute, Cranfield
University.
37
The Conservation Resource: Designated Areas
Internationally Important Features: The SAC and SPA
The Breckland Special Area of Conservation (SAC) totalling 7,548 ha is designated under the EC
Habitats/Species Directive for the following features:
Features of grass-heath and heather heath habitats:
Inland dunes with open Corynephorus and Agrostis grasslands.
European dry heaths.
Semi-natural dry grasslands and scrubland on calcareous substrates (Festuco-Brometalia).
Natural eutrophic lakes with Magnopotamion or Hydrocharition-type vegetation (the
fluctuating meres).
Other qualifying features included in the Breckland SAC, but which are not the primary reason for
selection:
Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae,
Salicion albae).
Great Crested Newt Triturus cristatus.
Rex Graham Reserve SSSI is a SAC in its own right, as an important orchid site within calcareous
grassland (Festuco-Brometalia).
A number of wetland and fen SSSIs within Breckland are also of international importance:
Foulden Common, Great Cressingham Fen and Thompson Common contribute to the
Norfolk Valley Fens Special Area of Conservation for their calcium rich spring fed vegetation
(e.g. M13) and transitions to reed-swamp and other fen and wet grassland types. The SAC is
also listed for the presence of the Desmoulin’s whorl snail Vertigo moulinsiana, for example
at Thompson Common.
Market Weston and Hopton Fens are part of the Waveney and Little Ouse Valley Fens
Special Area of Conservation for their calcareous fen with saw sedge Cladium mariscus, for
purple moor-grass meadow vegetation on calcareous, peaty or clayey-silt-laden soils
(Molinion caeruleae) and EC Habitats and Species Directive-Annex II species: narrow-
mouthed whorl snail Vertigo angustior, and Desmoulin’s snail V. moulinsiana.
The Breckland Special Protection Area (SPA), the EC Directive on the conservation of wild birds
(79/409/EEC) (see: http://www.jncc.gov.uk/default.aspx?page=2016), is designated for qualifying
breeding populations of woodlark Lullula arborea, nightjar Caprimulgus europaeus and stone
curlew Burhinus oedicnemus. Recent population sizes of these species are given below:
38
Qualifying population
Recent population
estimate (year)
Woodlark Lullula arborea
430
2411 (2009)
Nightjar Caprimulgus europaeus
415
349 (2004)
248 (2010)
Stone Curlew Burhinus oedicnemus
115
230 (2009)
1 Woodlark numbers relate to numbers of singing males, not breeding pairs, and exclude additional
birds nesting on heathland outside of the Forestry Commission estate.
Sites of Special Scientific Interest (SSSIs)
Fifty five SSSIs are located in the Breckland NCA, with a further 31 in the periphery (within the 23 10
km squares of the Breckland region (Table 4, Figure 4). These SSSIs include sites also designated as
Special Protected Areas (SPAs), Special Areas for Conservation (SACs) and National Nature Reserves
(NNRs). Approximately 40% of the Breckland NCA is designated as SSSI. This is a very high level of
designation compared to other bio-geographic areas, for example 5% of the South Downs National
Character Area and only 2% of the Fens National Character Area are designated as SSSIs.
Three sites dominate the total designated area, Breckland Forest (18,079 ha), Breckland Farmland
(13,335 ha) and Stanford Training Area (STANTA) (4,681 ha).
The Breckland Farmland was designated for internationally significant breeding population
of stone curlew. However within the arable area there is also known, and potential, plant
and invertebrate interest, including populations of species largely or entirely restricted to
Breckland.
Breckland Forest (comprising the majority of Thetford Forest together with some other
land) is designated for populations of woodlark and nightjar that contribute to the Breckland
Special Protection Area, but nationally important assemblages of rare plants and
invertebrates are also important interest features of the SSSI. The large extent of the
Breckland Forest with its unimproved soils and varied mosaic of semi-natural habitats,
together mixed plantations interspersed by a network of open space, make this an
extremely valuable landscape of high nature conservation value.
STANTA is an extensive landscape comprising a mosaic of ancient heaths (>170 years old)
and a range of grass-heaths, the last of which were reverted after 1932 (Sheail 1979). There
are also with areas of plantation and wetland. Although historically supporting substantial
populations of stone curlew, much of the grass-heath is now only lightly grazed, and even
the youngest of these have now been accumulating organic matter and nutrients for over 68
years (since the establishment of the training area in 1942). In 1968 a minimum of 13 pairs
of stone curlew, and a likely total of 16 18 pairs, were breeding on sheep grazed breck or
heath in STANTA; in 1980 there was evidence of 22 pairs across 18 sites (Green and Bowden
1987), but in 2008 there was only one pair and in 2009 only 3 pairs (RSPB data, supplied by
NE), representing an almost complete collapse.
39
All other SSSIs are less than 600 ha in size, with the smallest being London Road Industrial Estate,
Brandon (0.11 ha).
Virtually all substantial areas of unimproved Breckland grass-heath or heathland that had escaped
conversion to arable by the late 1950s are now designated and protected as SSSIs. In addition
further SSSIs have been notified for their wetland or woodland biodiversity or habitats. Among
these, the pingo sites are particularly notable in a Breckland context.
National Nature Reserves (NNR)
There are four National Nature Reserves in Breckland. Cavenham Heath (204ha) and Brettenham
Heath (233ha) are both managed by Natural England, while Weeting Heath (137ha) and Thetford
Heath (98ha) are managed by Norfolk Wildlife Trust.
County Wildlife Sites (CWS)
There are 583 County Wildlife Sites in the Breckland area of interest, 383 of which are in Norfolk,
174 in Suffolk and 25 in Cambridgeshire (Figure 4). Thetford Forest Park and The Kings Forest
combined comprise 44% (5937 ha) of the total area designated as CWS (13,566 hectares), although
these overlap the Breckland Forest SSSI. The smallest CWS, Chiswick Avenue, is 53 m2 and
designated for its Sand Catchfly population. Approximately 50% of the total area of CWS is now
designated as SSSI, encompassing all or part of 164 sites.
Roadside Nature Reserves (RNR)
There are forty-eight Roadside Nature Reserves (RNRs) in the Breckland 10 km squares (Table 4).
The largest RNR (2.06 ha) is along the A1065 at Lakenheath, designated for its Breckland flora,
including field wormwood. The smallest (53.5 m2) in Mildenhall is designated for its sand catchfly
population.
40
Table 4. Interest features of the Sites of Special Scientific Interest (SSSIs) in the selected 23 10 km squares
encompassing Breckland. Sites in grey lie within the Breckland NCA. Interest features are those features
from the citation that are recognised by the Natural England database (ENSIS). * denotes Schedule 8 moss,
rather than a Schedule 8 plant
Feature of Designation
Site Name
Area (ha)
Grassland
Heath
Woodland
Wetland
Flowing Waters
Standing waters
Geological
Vascular plants
Invertebrates
RDB plant / Sch 8 plant
Nationally rare invert spp
Agg. of breeding birds
Agg. of non-breeding birds
Mammals
Amphibians
Bangrove Wood
18.3
X
Barnham Heath
76.5
X
X
X
Barnhamcross Common
67.3
X
X
Berner's Heath, Icklingham
233.5
X
X
Black Ditches, Cavenham
1.7
X
X
Blo’ Norton and Thelnetham Fen
21.1
X
Boughton Fen
15.8
X
Brackland Rough
10.7
X
Breckland Farmland
13,393
X
Breckland Forest
18,079
X
X
X
X
X
Bridgham & Brettenham Heaths
446.0
X
X
X
Bugg’s Hole, Thelnetham
4.0
X
Burgate Wood
29.8
X
Castle Acre Common
17.7
X
Cavenham-Icklingham Heaths
398.8
X
X
X
X
X
X
X
X
Cherry Hill & the Gallops, Barton
Mills
10.1
X
X
X
Chippenham Fen and Snailwell Poor’s
Fen
155.6
X
X
X
X
X
X
X
Cranberry Rough, Hockham
81.4
X
X
X
X
Cranwich Camp
12.6
X
X
X
X
Deadman's Grave, Icklingham
126.3
X
X
X
X
Devil’s Dyke
39.8
X
X
X
Didlington Park Lakes
25.9
X
X
East Harling Common
14.9
X
X
X
East Walton and Adcock’s Common
62.5
X
X
X
X
X
X*
X
East Wretham Heath
141.1
X
X
Elm Road Field, Thetford
5.0
X
X
Eriswell Low Warren
6.6
X
X
Fakenham Wood, Euston & Sapiston
Great Grove
201.1
X
Field Barn Heaths, Hilborough
18.7
X
Foulden Common
136.8
X
X
X
X
Foxhole Heath, Eriswell
84.5
X
X
X
X
X
Gooderstone Warren
22.0
X
Great Cressingham Fen
13.7
X
X
41
Site Name
Area (ha)
Grassland
Heath
Woodland
Wetland
Flowing Waters
Standing waters
Geological
Vascular plants
Invertebrates
RDB plant / Sch 8 plant
Nationally rare invert spp
Agg. of breeding birds
Agg. of non-breeding birds
Mammals
Amphibians
Grime's Graves
64.9
X
X
X
X
Hilgay Heronry
1.8
X
Hookswell Meadows, Gt Cressingham
16.1
X
X
X
Hopton Fen
15.2
X
Horringer Court Caves
3.8
X
How Hill Track
3.3
X
Kenninghall and Banham Fen with
Quidenham Mere
48.4
X
X
Knettishall Heath
91.2
X
X
Lackford Lakes
106.1
X
X
X
X
Lakenheath Poors Fen
5.2
X
Lakenheath Warren
570.6
X
X
X
Little Heath, Barnham
45.7
X
X
London Road Industrial Estate,
Brandon
0.1
X
Lordswell Field, Eriswell
3.1
X
X
Maidscross Hill, Lakenheath
45.2
X
X
X
Middle Harling Fen
12.7
X
X
Narborough Railway Embankment
7.8
X
X
New Buckenham Common
21.0
X
Newmarket Heath
297.3
X
X
X
Old Bodney Camp
32.2
X
X
Old Buckenham Fen
34.5
X
X
Pashford Poors Fen, Lakenheath
12.2
X
X
X
X
X
Potter’s Carr
6.3
X
RAF Lakenheath
115.5
X
X
X
X
Redgrave and Lopham Fen
127.1
X
X
Red Lodge Heath
20.8
X
X
X
Rex Graham Reserve
2.7
X
River Nar
212.4
X
Scoulton Mere
34.2
X
X
X
X
Shaker’s Lane
0.5
X
Shippea Hill
27.6
X
Snailwell Meadow
15.2
X
X
Soham Wet Horse Fen
33.8
X
X
Stallode Wash
34.1
X
X
X
Stanford Training Area (STANTA)
4597.0
X
X
X
X
X
X
X
X
X
X
X
Stanton Woods
66.1
X
Swangey Fen
48.6
X
X
42
Site Name
Area (ha)
Grassland
Heath
Woodland
Wetland
Flowing Waters
Standing waters
Geological
Vascular plants
Invertebrates
RDB plant / Sch 8 plant
Nationally rare invert spp
Agg. of breeding birds
Agg. of non-breeding birds
Mammals
Amphibians
The Brinks, Northwold
16.3
X
The Glen Chalk Caves
1.6
X
Thetford Golf Course & Marsh
119.6
X
X
X
X
Thetford Heaths
269.4
X
X
X
X
X
X
Thompson Water, Carr & Common
156.0
X
X
X
X
X
X
X
Wangford Warren & Carr
65.6
X
Wayland Wood
31.8
X
Weather & Horn Heaths, Eriswell
130.8
X
X
Weeting Heath
140.8
X
X
X
X
Westhall Wood and Meadow
43.1
X
X
West Stow Heath
42.6
X
X
X
X
Weston Fen
49.6
X
X
X
Wilde Street Meadow, Mildenhall
10.9
X
Wortham Ling
53.2
X
X
Wretham Park Meres
27.5
X
X
Wretton
20.6
X
43
Table 5. The 32 Breckland Sites of Special Scientific Interest containing grass-heath. A number of sites dominated by
other habitats are not included, despite containing minor areas of dry grass-heath. Dry grassland and heathland
National Vegetation Communities (NVC) are given for each site. Note that NVC features listed relate to those known
at the time of notification and are not necessarily a complete account of what is currently present (Source: Natural
England). Although the notified feature may be “CG7abde”, pooling of these sub-communities into a single aggregate
feature does not imply all are present on a site. Neither CG7d or CG7e are known to occur in Breckland (Rodwell
1992), as confirmed by the 1992 Norfolk and Suffolk Chalk Grassland survey commissioned by Natural England
Site of Special Scientific Interest
containing grass-heath resource
Area
(ha)
Calcicolous grasslands
Shingle, strandline and
sand-dune communities
Calcifugous grasslands
Dwarf-shrub heath
Mesotrophic grasslands
Notified dry grassland and
heathland NVC communities
CG
SD
U
H
MG
Barnham Heath
76.5
X
X
CG7abde, U1bcdf, U4, U4/20
Barnhamcross Common
67.3
X
X
X
CG6, SD10, U1bcdf
Berners Heath, Icklingham
233.5
X
X
X
X
CG7abde, SD8, U1bcdf, H1
Black Ditches, Cavenham
1.7
X
CG2
Bridgham & Brettenham Heaths
446
X
X
X
X
CG7abde, U1abdf, U1e, SD8,
H1
Cavenham-Icklingham Heaths
398.8
X
X
X
SD11, U1bcdf, H1
Cherry Hill & The Gallops, Barton
Mills
10.1
X
CG6
Cranwich Camp
12.6
X
CG7abde
Deadmans Grave, Icklingham
126.3
X
X
CG7abde, U1bcdf
East Harling Common
14.9
X
CG2, CG6
East Wretham Heath
141.1
X
X
X
CG7abde, SD8, U1bcdf
Elm Road Field, Thetford
5
X
CG6
Eriswell Low Warren
6.6
X
X
CG7abde, U1bcdf
Field Barn Heaths, Hilborough
18.7
X
CG2
Foulden Common
136.8
X
CG2, CG6
Foxhole Heath, Eriswell
84.5
X
X
X
CG7abde, CG7c, U1a, U1bcdf,
H1
Gooderstone Warren
22
X
X
X
CG2, SD10, U1bcdf, H1
Grimes Graves
64.9
X
X
X
X
CG7abde, SD8, U1e, H1
Knettishall Heath
91.2
X
X
X
CG7abde, U1bcdf, H1
Lakenheath Warren
570.6
X
X
X
CG5, CG7abde, CG7c, SD10,
SD11, U1a, U1bcdf, U4
Little Heath, Barnham
45.7
X
X
CG7abde, CG7c, U1a, U1bcdf
Lordswell Field, Eriswell
3.1
X
X
CG7abde, U1a, U1bcdf
Maidscross Hill, Lakenheath
45.2
X
X
X
CG7abde, SD11, U1bcdf
Narborough Railway Embankment
7.8
X
CG2, CG7abde
Old Bodney Camp
32.2
X
X
X
CG7abde, SD8, SD12, U1bcdf
RAF Lakenheath
115.5
X
X
CG7abde, U1bcdf
Stanford Training Area (STANTA)
4597
X
X
X
X
X
CG2, CG6, CG7abde, SD8,
U1bcdf, U1e, H1, H9, MG5
Thetford Golf Course & Marsh
119.6
X
X
X
CG2, CG7abde, U1bcdf, H1
Thetford Heaths
269.4
X
X
X
CG7abde, CG7c, U1a, U1bcdf,
H1
Thompson Water, Carr & Common
156
X
X
X
CG2, SD10, U1bcdf
Wangford Warren & Carr
65.6
X
X
CG7c, U1a, U1bcdf
Weather & Horn Heaths, Eriswell
130.8
X
X
U1bcdf, H1
Weeting Heath
140.8
X
X
CG7abde, CG7c, U1e
West Stow Heath
42.6
X
X
X
CG7abde, U1bcdf, H1
44
Environmentally Sensitive Area (ESA)
The Breckland Environmentally Sensitive Area was designated in 1988, covering 94,535ha (Figure
2), it is one of 22 such areas in England. The scheme, now administered by Natural England, has
several objectives, including the maintenance and enhancement of the nature conservation value
of heathland, river valley grasslands and arable land. The scheme provides incentives to landowners
through area payments against standard prescriptions to meet environmental objectives, together
with capital payments to support specific projects, for example, the re-introduction of grazing and
restoration of heathland vegetation. In addition to grant aiding management of heaths and river
valley grasslands, the scheme established uncropped wildlife strips (cultivated margins) on arable
land, one of only two ESAs in the country to do so, as well promoting conservation headlands
(unsprayed areas of cereals) and incentives to maintain over-wintered stubbles. To date still it is the
only national statutory designation to have been conferred on Breckland. Under the agri-
environment scheme which replaces it, Environmental Stewardship, Breckland currently remains
one of Natural England’s priorities for targeting funding.
Important Plant Areas (IPAs)
The Breckland Important Plant Area (IPA) has been defined and championed by Plantlife to assist in
targeting protection of vascular plant, bryophyte, lichen and algal species. The IPA comprises three
layers (Figure 6); a Core Layer that indicates the key areas of botanical interest and is based on
existing statutory protection network boundaries (SSSIs); a Zone of Opportunity Layer that provides
a wide boundary, indicating an area with potential for restoration to support key features in the
future; the third layer comprises those tetrads identifying the Criterion A species (Globally and
European threatened plants and other threatened endemics or near endemics) (pers. comm.
Pankhurst, Plantlife).
45
Figure 4. Location of designated sites within the Breckland National Character Area and the 23 10 km Ordnance Survey grid squares: a) Sites of
Special Scientific Interest (SSSI); b) County Wildlife Sites (CWS) and Roadside Nature Reserves (RNR
46
a)
Figure 5. Location of designated sites within the Breckland National Character Area and the 23 10 km Ordnance Survey grid squares: a)
Special Area for Conservation (SAC); b) Special Protected Area (SPA)
47
Figure 6. Location of Plantlife’s Important Plant Areas (IPA), within the Breckland National Character Area
and the 23 10 km Ordnance Survey grid squares
48
Breckland Biodiversity Audit: Methodology
Analysing Long-Term Trends in Weather
Weather data were collated and analysed in order to:
Quantify and contrast the Breckland climate to that of East Anglia and Southern England
(see Climate section).
Analyse the extent and magnitude of any change in weather during recent decades.
Consider qualitatively the potential consequences for Breckland biodiversity.
For both rainfall and temperature analyses, seasons (each of three months duration) were defined
as follows:
Spring: March - May
Summer: June - August
Autumn: September - November
Winter: December - February
Daily precipitation (total mm) and daily minimum and maximum temperature (°C) data were
obtained from the British Atmospheric Data Centre (BADC)
(http://badc.nerc.ac.uk/home/index.html). Forty six weather stations were located in the Breckland
region. However, data coverage was intermittent and no single station covered the whole of the
previous century.
Individual stations that provided the longest and most consistent run of data for temperature, and
separately for rainfall, were selected. In order to fill in gaps in the data time series recorded at
these primary references stations, records from other subsidiary stations were also used. The
relationship between the subsidiary station and reference station was first established using linear
regression for all days with overlapping mutual records, and then this equation was used to predict
values missing from the reference station. Full details are provided in Supplementary Materials in
the Appendix.
Elveden Hall was used as the primary station for rainfall data, with Santon Downham and Thetford
Water Works selected as subsidiary stations. Santon Downham, Grimes Grave and Santon
Downham were used as primary stations, with Honington used for subsidiary data. The locations of
all weather stations used are shown in Figure 7.
Analyses of trends through time
The relationship between total rainfall (mm) per season, and mean daily minimum and mean daily
maximum temperatures per season over time (across years) was examined by relating weather to
year using linear regression (with normal error). Whether the numbers of drought events, numbers
of extreme rainfall events and number air frost days per season had changed through time was
examine by modelling weather against year, using general linear models with Poisson error terms
(to account for the discrete count data with small range and non-normal error). Significance of
trends through time were examined using Wald Chi square tests.
49
Figure 7. Locations of stations in Breckland from which weather data were sourced
50
Defining the Area of Species Record Capture
It was felt important to capture the full extent of characteristic species when collating records. Data
extraction and mapping, therefore, considers a slightly larger area than that of the NCA. This wider
area encompasses the largest area classified as Breckland by either the National Character Area
(1019 km2) or the Breckland Environmentally Sensitive Area (945 km2) and adds a 1km buffer to this
as a safety margin. Species observations (records) were collated from all available sources for each
of the 23 10 km grid squares that lay within or included part of the combined and buffered (1 km)
National Character Area and Environmentally Sensitive Area (Figure 2).
The collation of records, from 23 10km squares resulted in the inclusion of records from sites
generally considered to lie outside of Breckland, for example Redgrave and Lopham Fens. The
compilation of data from 10 km squares was important for a number of reasons:
Several datasets were only available as units of 10 km grid squares.
Some records were only available at 10 km resolution.
Collation, and subsequent mapping, of records from the wider area would allow questioning
of the suitability of the Breckland National Character Area as a definitive area for the
region’s important specialists.
This is referred to subsequently as the Breckland “region”, to distinguish it from the Breckland NCA
or any other boundary.
Collation and Sources of Species Records
Species data were imported and managed using the software Recorder 6 (www.jncc.gov.uk/page-
4592).
Sources of Species Records
Key data sources included: Local Records Centres of Norfolk, Suffolk and Cambridgeshire, the
National Biodiversity Network gateway, Invertebrate Site Register, County Natural History and
Recording Societies and the Breckland Rare Plant Database. These are discussed in turn below and a
full list of data sources, including the number of records provided, is given in Table 12.
Local Records Centres (LRC)
The three local biological records centres in the selected area; the Norfolk Biodiversity Information
Service (NBIS), Suffolk Biological Records Centre (SBRC) and Cambridgeshire & Peterborough
Environmental Records Centre (CPERC) provided all species data available for the 23 selected 10 km
grid squares. These Local Record Centres actively collect data from local recorders and recording
schemes and where possible from national recording schemes. They also provide information to the
NBN Gateway.
National Biodiversity Network (NBN)
Records were sourced from the National Biodiversity Network (NBN). NBN is a national database
that holds records from 493 organisations, including county recording schemes and natural history
and taxonomy groups. Access to data was granted by 38 of 44 organisations holding records in the
23 Breckland grid squares (Table 12). Access was not provided to the Dipterists Forum Recording
51
Scheme for Stilt & Stalk Flies, Dragonfly records from the British Dragonfly Society's Dragonfly
Recording Network for the period between 1992 and 2009, Fungal Records Database of Britain and
Irelandand the Threatened Bryophyte Database. Whilst access to these databases would certainly
have improved our understanding of the occurrence and distribution of species in these groups,
other databases, such as those from LRCs, include records for these groups. In addition, we also had
access to the British Dragonfly Society's former Dragonfly Recording Network prior to 1992.
Invertebrate Site Register (ISR)
Data obtained from the NBN included all available records from the Invertebrate Site Register (ISR).
The ISR was established by English Nature to identify, document and evaluate sites of importance
for the conservation of terrestrial and freshwater invertebrates in Great Britain. The national
database holds records from 1900 to 2005, with the majority of observations made in the late
1980s. ISR data for the Breckland square TF80 were not available.
County Natural History and Recording Societies
A large number of county recording societies, such as Norfolk Bryology Group, provide data to the
relevant Local Recording Centre and these would have reached the BBA via the LRCs.
Both the Norfolk and Suffolk branches of Butterfly Conservation provided all of their records for the
Breckland grid squares. The Suffolk Moth Group provided all records from the area, with the
exception of a small number that were confidential; it is not known for which species confidential
records exist. This is an unfortunate omission because the confidential records may include
information on priority species of importance to the audit. The Norfolk Moth Group provided their
entire Norfolk database to NBIS, from whom we obtained the Breckland records. The Freshwater
Invertebrate Survey of Suffolk, the British Plant Gall Society and the British Arachnological Society
provided records directly to the BBA. Records from all these organisations were not duplicated in
other databases, with the exception of a small number of records passed on to multiple
organisations by individual recorders.
Breckland Rare Plant Database (BRPD)
A number of vascular plant species known to be largely or entirely restricted to the Breckland
region had long been a focus of interest among botanists and conservationists. During the mid
1970s Gigi Crompton, of the Cambridge University Botanic Garden, collated all known historic
records for selected rare vascular species in Breckland (Table 6) (Compton, 1977). Historic and
known extant sites were visited and populations recorded in detailed field surveys during 1975-77.
The resulting survey data, arranged by focal species, were collated separately for Norfolk and
Suffolk and archived with the Nature Conservation Council offices in Norwich and Bury St Edmunds.
In Suffolk, populations of 31 focal species were systematically surveyed from 1991 and onwards by
Yvonne and David Leonard, with many populations receiving annual survey. Gillian Beckett was
commissioned by English Nature to collate available records for 23 rare plant species in the Norfolk
Breckland, including 12 species not surveyed by Gigi Crompton, and to survey known and lost sites
during 1992 (Beckett, 1993). A small number of species and sites were selected to receive follow-on
work, conducted in 1993-4 (Beckett, 1995) and in subsequent years (Gibbons, 2000). However,
many sites and species lacked any consistent or systematic survey coverage in the last 15 years.
Data collated during this period and deposited with English Nature included records for smooth
rupturewort Herniaria glabra sites surveyed by Jean Gaffney through the 1980s and 1990s.
52
For a subset of rare plants entirely or largely restricted to Breckland (including field mugwort
Artemisia campestris, spiked speedwell Veronica spicata, Spanish catchfly Silene otities, grape
hyacinth Muscari neglectum, perennial knawel Scleranthus perennis ssp. prostratus, proliferous
pink Petrorhagia prolifera and fingered speedwell Veronica triphyllos), it is likely that all existing
populations have been located and identified. For a further selection of species (e.g. Breckland
thyme Thymus serpyllum, Herniaria glabra, Breckland speedwell Veronica praecox, purple-stemmed
cats-tail Phleum phleoides), our understanding of distribution is good but thought to be incomplete.
For a further group of species (e.g. burr medic Medicago minima, fine-leaved sandwort Minuartia
hybrida, lucerne Medicago sativa ssp. falcata, dense silkybent Apera interrupta) specific surveys
have not been conducted, although records of these species were made during monitoring of focal
species, and records under-represent their distribution.
Breckland Rare Plant Survey data had not been entered into any electronic database previously and
were not fully captured within the LRCs of either Suffolk or Norfolk. Data for 11 Breckland speciality
plants covered by Gigi Crompton’s surveys in 1975-7 were collated by P. Dolman (Dolman and
Sutherland 1992). The audit updated and greatly expanded this database. Records for 28 rare
Breckland plant species (Table 6) were compiled to create the Breckland Rare Plant Database
(BRPD), collated in April 2010 by Helen Jobson, a University of East Anglia student working with
Plantlife. Suffolk Rare Plant Survey records were obtained from the Natural England office in Bury St
Edmunds and Norfolk Rare Plant Survey records were obtained from the Natural England office in
Norwich. For each of the focal species that had received species-specific survey visits, every dated
survey record was captured. In addition, any incidental records of additional rare plants (e.g.
Phleum phleoides, sand catchfly Silene conica, Apera interupta, Medicago minima, Medicago sativa
ssp. falcata) noted during surveys of focal populations, were also compiled in the electronic
database. Further vascular plant records were obtained from the Conservation Room at STANTA,
Gillian Beckett’s electronic files and Plantlife records for tower mustard Arabis glabra and red-
tipped cudweed Filago lutescens.
53
Table 6. Rare vascular plant species for which records were collated into the Breckland Rare Plant
Database (BRPD). Key surveys generating records are shown: Y indicates populations systematically
surveyed; (Y) indicates lower priority and casual survey; associated records species not subject to survey
for which records were extracted from surveys of focal species
Crompton
(1975-77)
Beckett
(Norfolk
only, 1992)
Beckett
(1993-4)
Leonard
(Suffolk only,
1991-2009)
Associated
records
Alyssum alyssoides
Y
Y
Y
Apera interrupta
Y
Arabis glabra
Y
Y
Y
Artemisia campestris
Y
Y
Y
Carex ericetorum
Y
Y
Corynephorus canescens
Y
Dianthus deltoides
Y
Y
Y
Festuca longifolia
Y
Y
Y
Filago lutescens
Y
Galium parisiense
Y
Y
Herniaria glabra
Y
Y
Y
Y
Hypochaeris glabra
Y
Hypochaeris maculata
Y
Medicago minima
(Y)
Y
Y
Medicago sativa ssp. falcata
Y
Y
Minuartia hybrida
Y
Muscari neglectum
Y
Petrorhagia prolifera
Y
Phleum phleoides
Y
Y
Y
Y
Scleranthus annuus
Y
Scleranthus perennis ssp.
prostratus
Y
Silene conica
Y
Y
Y
Silene otites
Y
Y
Y
Y
Thymus serpyllum
Y
Y
Y
Y
Y
Veronica praecox
Y
Y
Y
Veronica spicata ssp. spicata
Y
Y
Y
Veronica triphyllos
Y
Y
Y
Veronica verna
Y
Y
Y
Y
Other Datasets, Reports and Records from Individuals
Detailed annual plant, invertebrate and vertebrate biodiversity surveys of the Elveden site have
been commissioned by Center Parcs since 1990. All data from the 1990-2009 surveys were obtained
by the BBA.
Invertebrate records collected by Mark Telfer and Brian Eversham between 1993 and 1994 from a
number of grass-heaths, including Lakenheath Warren and road verge sites (Telfer and Eversham
1995). All records were obtained by the BBA.
All records were also obtained from the report “Invertebrates of Red Lodge Heath in relation to
other sites in the Breckland National Character Area: Aculeate Hymenoptera and Coleoptera”
(Harvey, 2004). These included species recorded during the survey of Red Lodge Heath and records
collated by Peter Harvey from other sources.
34,369 records were obtained from the ADAS report to MAFF “Biological Monitoring of Arable Field
Margins in the Breckland ESA, 1989-1996” (ADAS 1997). However, 32,177 were only identified to
family or genus level and contained few priority invertebrate records.
54
The BBA also obtained unique species records found in letters, personal communication and
reports stored in the offices of Forestry Commission, SBRC, Natural England (Bury St Edmunds and
Norwich), STANTA, NBIS, Suffolk and Norfolk Wildlife Trusts. Generally these undigitised records
were pre-1990 and many are thought to have been captured by the ISR and therefore be
duplicates. However, the paper records obtained by the BBA provide, in contrast to those in the ISR,
site and recorder names and more precise grid references. A sub-set of approximately half of the
relevant Breckland County Wildlife Site files held by NWT were examined for records. Very few
unique records of Breckland conservation priority species were obtained and further examination
of site files at SWT was therefore not considered useful for the purpose of collating species records.
However, these files contain valuable information on plant assemblages and site habitat conditions.
Unpublished theses and dissertations (Ph.D., MSc. and BSc.) from the University of East Anglia and
Anglia Ruskin University were assessed for additional species records. Few contained records of
priority or Breckland specialist species. However, useful records for arachnidae were obtained from
Sastre (2003), and carabid records from Lin (2005) and Bertoncelj (2010). Records were also
obtained from current students, Scott Pedley, Chris Jones and Ben Christie.
Thirty-two species recorders and taxonomic experts provided additional and previously un-
captured records. Individuals providing large numbers of records are indicated in Table 12.
Duplicate Records
Records from NBIS, SBRC and CPBRC did not contain large numbers of records also duplicated in the
ISR or NBN. However, a number of records passed on to multiple organisations by individual
recorders will have resulted in duplicate records. Datasets obtained from NBN frequently included
multiple entries of the same record. Most of the multiple records had NBN observation keys (codes)
and could be removed. However, records from the ISR and the former Dragonfly Recording Scheme
did not have observation keys and duplicates could not be removed.
As analysis considers only the overall representation of each species in each 1 km x 1 km square,
retained duplicate and multiple records are not considered a problem; therefore duplicates were
not filtered further as this would have been excessively time consuming.
Record coverage and completeness
Due to the confidentiality of a number of mammal records, particularly those relating to badgers,
the BBA database is incomplete in relation to mammals. Mammal species were therefore, included
in the list of conservation priority species, but were not included in the mapping of priority species.
Avian species records passed to the Local Records Centres, often via county bird reports, provide
incomplete, idiosyncratic coverage compared to the systematic monitoring data conducted by the
British Trust for Ornithology (BTO) with funding from the Joint Nature Conservancy Council (JNCC).
Bird species for which records were collated are included in the list of conservation priority species,
but due to poor coverage of records, they are not included in the mapping of priority species. It is
recommended that subsequent analysis should be conducted using BTO Breeding Bird Survey (BBS)
and Atlas data to identify those bird species for which the region supports nationally important
populations or wintering numbers.
55
Recommendation
BTO be commissioned to analyse Atlas data, BBS data and other survey coverage from
Breckland, in relation to East Anglia and lowland England, to identify which species have
regionally or nationally important populations.
Species historic to Breckland
Where possible conservation priority species whose presence in Breckland is now only historic (i.e.
locally extirpated or nationally extinct) were identified, using extinct statuses (Red Data Book
Extinct), local knowledge, information from taxonomic experts and the Natural England publication
Lost Life: England’s lost and threatened species (Brown et al. 2010).
Data quality and resolution
A species record is defined as an observation of one species, in one place and at given
time.Mandatory and preferred fields for collated species records were:
Identification to species level
In addition to the 32,177 records from ADAS, a further 3525 records were received that were not
identified to species level. These records were obtained from a range of sources, including Local
Records Centres, ISR and national recording schemes.
Grid reference
29,096 records (3.5%) were received from locations outside of the 23 Breckland 10 km grid squares.
These included records supplied with incorrect grid references and valid records from outside the
selected Breckland area.
Most collated records had grid references resolved to a minimum of 1 km. However, 33,877 records
(4.1%) were only resolved to 10 km. Species from these records were included in species and
priority lists, but were not considered when mapping to a 1 km resolution.
151,138 observations, primarily of flowering plants, were recorded as tetrads. For mapping at a 1
km resolution it was assumed that the observed species was found in all four 1 km squares that
made up the tetrad, i.e. a single tetrad observation was converted to four single 1 km records. This
will over-represent the true distribution of some scarcer species and artificially smooth species
distributions. However, this is offset by the fact that many SSSI sites straddle a number of 1 km
squares but species records are often placed on a hypothetical centre point.
Observation date
There were 904 records without an observation date or that had large date ranges that spanned
either side of the selected cut-off date of 1980 (see Data Mapping section for further details).
These were included in species and priority lists but were removed prior to 1 km mapping of
priorities.
56
Species recorder
A species recorder and/or determiner were unavailable for approximately 20% of records, many
obtained from the ISR. This prevented the validation of some uncertain species records.
Species lists and validation
The total number of species and total species list were collated from all the valid records. From this,
all species with a national or international conservation status were identified to create a list of
Breckland conservation priority species (see below for more information regarding designations).
Local Records Centres receive validated species records from county recorders. In addition, records
received from other recorders are passed to county recorders for validation. This validation is the
foundation of how local record centres work and ensures the data are fit for purpose. However, this
process is not completely failsafe. It was therefore important to validate the priority list of species,
and to filter inaccurate or infeasible records. The first draft of the Breckland conservation priority
species list was shown to species experts at the Species and Habitat Workshop held at UEA on 5th
October 2009, with separate lists examined for all groups of taxa. Later iterations of the Breckland
conservation priority species list were further validated by circulation to a number of experts who
were asked to comment on any records that they considered suspect, or to provide additional
species that they knew to occur.
Following validation, forty-seven species were removed having been identified as not occurring in
the Breckland area, as being incorrect identifications, were considered to be garden escapes,
recently introduced or deliberately planted species (Table 7).
Eleven species were identified by experts as occurring in Breckland and being of importance
(priority or Breckland specialists), but for which there were no records available. These species
were included in the priority lists.
57
Table 7. Species for which records were excluded, showing the source and reasons for exclusion
* a number of other species are recorded in Breckland as accidentals or vagrants and with no regular or
passing residence are not of management concern in Breckland
Group
Species
Source of validation
Reason for exclusion
Conifer
Pinus sylvestris
BBA
Widely planted, native status uncertain
Flowering plant
Buxus sempervirens
BBA
Widely planted as game cover
Flowering plant
Calamagrostis scotica
Ian Simper
Most likely misidentification
Flowering plant
Centaurea calcitrapa
Ian Simper
Not native to Breckland
Flowering plant
Clinopodium menthifolium
Ian Simper
Not native to Breckland
Flowering plant
Colchicum autumnale
Neal Armour-Chelu
Not native to Breckland, gardened species
Flowering plant
Meconopsis cambrica
Ian Simper
Not native to Breckland