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

December 2010

Publisher: School of Environmental Sciences, University of East Anglia, Norwich
ISBN: 978-0-9567812-0-8

Authors:

Paul M Dolman

University of East Anglia

Chris Panter

Hannah L. Mossman

Manchester Metropolitan University

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

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

Commissioned by the following organisations:

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

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

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

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,

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.

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.

 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.

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.

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

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.

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).

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.

 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.

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.

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.

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.

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.

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

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.

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

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

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.

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.

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.

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.

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.

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

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

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

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

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

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

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

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).

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

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

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

(1.4%)

Open Water

1.7

Total area:

1019

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

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.

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:

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.

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.

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

Barnham Heath

76.5

Barnhamcross Common

67.3

Berner's Heath, Icklingham

233.5

Black Ditches, Cavenham

1.7

Blo’ Norton and Thelnetham Fen

21.1

Boughton Fen

15.8

Brackland Rough

10.7

Breckland Farmland

13,393

Breckland Forest

18,079

Bridgham & Brettenham Heaths

446.0

Bugg’s Hole, Thelnetham

4.0

Burgate Wood

29.8

Castle Acre Common

17.7

Cavenham-Icklingham Heaths

398.8

Cherry Hill & the Gallops, Barton

Mills

10.1

Chippenham Fen and Snailwell Poor’s

Fen

155.6

Cranberry Rough, Hockham

81.4

Cranwich Camp

12.6

Deadman's Grave, Icklingham

126.3

Devil’s Dyke

39.8

Didlington Park Lakes

25.9

East Harling Common

14.9

East Walton and Adcock’s Common

62.5

East Wretham Heath

141.1

Elm Road Field, Thetford

5.0

Eriswell Low Warren

6.6

Fakenham Wood, Euston & Sapiston

Great Grove

201.1

Field Barn Heaths, Hilborough

18.7

Foulden Common

136.8

Foxhole Heath, Eriswell

84.5

Gooderstone Warren

22.0

Great Cressingham Fen

13.7

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

Hilgay Heronry

1.8

Hookswell Meadows, Gt Cressingham

16.1

Hopton Fen

15.2

Horringer Court Caves

3.8

How Hill Track

3.3

Kenninghall and Banham Fen with

Quidenham Mere

48.4

Knettishall Heath

91.2

Lackford Lakes

106.1

Lakenheath Poors Fen

5.2

Lakenheath Warren

570.6

Little Heath, Barnham

45.7

London Road Industrial Estate,

Brandon

0.1

Lordswell Field, Eriswell

3.1

Maidscross Hill, Lakenheath

45.2

Middle Harling Fen

12.7

Narborough Railway Embankment

7.8

New Buckenham Common

21.0

Newmarket Heath

297.3

Old Bodney Camp

32.2

Old Buckenham Fen

34.5

Pashford Poors Fen, Lakenheath

12.2

Potter’s Carr

6.3

RAF Lakenheath

115.5

Redgrave and Lopham Fen

127.1

Red Lodge Heath

20.8

Rex Graham Reserve

2.7

River Nar

212.4

Scoulton Mere

34.2

Shaker’s Lane

0.5

Shippea Hill

27.6

Snailwell Meadow

15.2

Soham Wet Horse Fen

33.8

Stallode Wash

34.1

Stanford Training Area (STANTA)

4597.0

Stanton Woods

66.1

Swangey Fen

48.6

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

The Glen Chalk Caves

1.6

Thetford Golf Course & Marsh

119.6

Thetford Heaths

269.4

Thompson Water, Carr & Common

156.0

Wangford Warren & Carr

65.6

Wayland Wood

31.8

Weather & Horn Heaths, Eriswell

130.8

Weeting Heath

140.8

Westhall Wood and Meadow

43.1

West Stow Heath

42.6

Weston Fen

49.6

Wilde Street Meadow, Mildenhall

10.9

Wortham Ling

53.2

Wretham Park Meres

27.5

Wretton

20.6

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

Barnham Heath

76.5

CG7abde, U1bcdf, U4, U4/20

Barnhamcross Common

67.3

CG6, SD10, U1bcdf

Berners Heath, Icklingham

233.5

CG7abde, SD8, U1bcdf, H1

Black Ditches, Cavenham

1.7

CG2

Bridgham & Brettenham Heaths

446

CG7abde, U1abdf, U1e, SD8,

Cavenham-Icklingham Heaths

398.8

SD11, U1bcdf, H1

Cherry Hill & The Gallops, Barton

Mills

10.1

CG6

Cranwich Camp

12.6

CG7abde

Deadmans Grave, Icklingham

126.3

CG7abde, U1bcdf

East Harling Common

14.9

CG2, CG6

East Wretham Heath

141.1

CG7abde, SD8, U1bcdf

Elm Road Field, Thetford

CG6

Eriswell Low Warren

6.6

CG7abde, U1bcdf

Field Barn Heaths, Hilborough

18.7

CG2

Foulden Common

136.8

CG2, CG6

Foxhole Heath, Eriswell

84.5

CG7abde, CG7c, U1a, U1bcdf,

Gooderstone Warren

CG2, SD10, U1bcdf, H1

Grimes Graves

64.9

CG7abde, SD8, U1e, H1

Knettishall Heath

91.2

CG7abde, U1bcdf, H1

Lakenheath Warren

570.6

CG5, CG7abde, CG7c, SD10,

SD11, U1a, U1bcdf, U4

Little Heath, Barnham

45.7

CG7abde, CG7c, U1a, U1bcdf

Lordswell Field, Eriswell

3.1

CG7abde, U1a, U1bcdf

Maidscross Hill, Lakenheath

45.2

CG7abde, SD11, U1bcdf

Narborough Railway Embankment

7.8

CG2, CG7abde

Old Bodney Camp

32.2

CG7abde, SD8, SD12, U1bcdf

RAF Lakenheath

115.5

CG7abde, U1bcdf

Stanford Training Area (STANTA)

4597

CG2, CG6, CG7abde, SD8,

U1bcdf, U1e, H1, H9, MG5

Thetford Golf Course & Marsh

119.6

CG2, CG7abde, U1bcdf, H1

Thetford Heaths

269.4

CG7abde, CG7c, U1a, U1bcdf,

Thompson Water, Carr & Common

156

CG2, SD10, U1bcdf

Wangford Warren & Carr

65.6

CG7c, U1a, U1bcdf

Weather & Horn Heaths, Eriswell

130.8

U1bcdf, H1

Weeting Heath

140.8

CG7abde, CG7c, U1e

West Stow Heath

42.6

CG7abde, U1bcdf, H1

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).

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

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)

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

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.

Figure 7. Locations of stations in Breckland from which weather data were sourced

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

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.

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.

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

Apera interrupta

Arabis glabra

Artemisia campestris

Carex ericetorum

Corynephorus canescens

Dianthus deltoides

Festuca longifolia

Filago lutescens

Galium parisiense

Herniaria glabra

Hypochaeris glabra

Hypochaeris maculata

Medicago minima

(Y)

Medicago sativa ssp. falcata

Minuartia hybrida

Muscari neglectum

Petrorhagia prolifera

Phleum phleoides

Scleranthus annuus

Scleranthus perennis ssp.

prostratus

Silene conica

Silene otites

Thymus serpyllum

Veronica praecox

Veronica spicata ssp. spicata

Veronica triphyllos

Veronica verna

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.

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.

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.

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 ask

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

Abstract