IMPORTANT ARABLE AREAS Identifying priority sites for arable plant conservation in the United Kingdom Important Arable Plant Areas BOB GIBBONS/NATURAL IMAGE BOB GIBBONS/NATURAL

This fine show of Corn Marigold and Common Poppy in Dorset appeared for just one season, through lack of effective herbicide treatment.

Report written by: Andrew Byfield and Phil Wilson Contents This report is a summarised version of a full paper authored by Phil Wilson (Wilson, in prep.). Summary 1 Acknowledgements A large number of people have contributed to this report, in the form of site and survey information, and in 1. Introduction 3 commenting on the Important Arable Plant Areas concept and criteria presented here. In particular we should like to thank Liz McDonnell (English Nature-RDS),Andy Jones (Countryside Council for Wales), 2.The rise and fall of arable 4 David Pearman (Botanical Society of the British Isles), Mark Stevenson (Defra), Simon Smart (FWAG Wiltshire), Michael Woodhouse (FWAG), Ron Porley (English Nature), Jill Sutcliffe (English Nature), Chris 3. Conserving arable plants: 8 Sydes (Scottish Natural Heritage) and Kevin Walker (Centre for Ecology & Hydrology); and Joanna Bromley, a way forward Jenny Duckworth, Nicola Hutchinson, Beth Newman, Dominic Price and Joe Sutton in the resources and UK conservation teams at Plantlife International. 4. Criteria for the selection of 10 The BSBI and Centre for Ecology and Hydrology Biological Records Centre is thanked for making available Important Arable Plant Areas the 10-km square coincidence map of rare arable plants reproduced as Map 1. 5. Initial findings 14 This report was commissioned as part of Plantlife International’s species recovery programme Back from the Brink, with generous financial support from English Nature and the Esmée Fairbairn Charitable Foundation. References and further reading 17 Report citation Byfield,A.J. & Wilson, P.J. (2005). Important Arable Plant Areas: identifying priority sites for arable plant Appendix 17 conservation in the United Kingdom. Plantlife International, Salisbury, UK.

Plantlife is a charity dedicated exclusively to conserving all forms of plant life in their natural habitats, in the UK, Europe and across the world.The charity has 12,500 members and owns 23 nature reserves. Plantlife is ‘Lead Partner’ for 77 species under the UK Government’s Biodiversity Initiative. Conservation of these threatened species is delivered through the charity’s Back from the Brink species recovery programme, which is jointly funded by Countryside Council for Wales, English Nature, Scottish Natural Heritage, charitable trusts, companies and individuals. It involves its members as volunteers (Flora Guardians) in delivering many aspects of this work. Plantlife’s head office is in Salisbury,Wiltshire and the charity has national offices in Wales and Scotland.

Plantlife International - The Wild Plant Conservation Charity, 14 Rollestone Street,, Salisbury,Wiltshire SP1 1DX Tel:+44 (0) 1722 342730 Fax: +44 (0) 1722 329035 e-mail: [email protected] website: www.plantlife.org.uk ©August 2005 ISBN: 1 904749-15-1 Important Arable Plant Areas BOB GIBBONS/NATURAL IMAGE BOB GIBBONS/NATURAL

Extreme rarities such as Field Cow-wheat ( arvense) are largely extinct as arable plants in the UK

Summary Cornfield flowers represent one of the most colourful and culturally significant elements of the British landscape, yet remain the single most threatened element of our flora. No fewer than seven species are extinct as arable plants across the United Kingdom, whilst others teeter on the verge of extinction: 54 species of arable land are considered threatened at the present time. Arable land is also of importance for a range of rare bryophytes - though these are only considered briefly in this report.

Yet in spite of being the most critically threatened group of plants in Britain today, arable plants have received very little attention from nature conservationists up until very recently, all this despite their enormous value as a food source for a vast array of farmland insects, small mammals and birds. In short, the arable community remains the least studied of any major plant habitat in Britain at the present time.

Fortunately the tide seems to be turning. The UK Government has recognised the importance of arable plants through their identification of 12 arable vascular plant species, five arable bryophyte species - and the cereal field margin habitat itself - as priorities under the UK Biodiversity Action Plan (BAP). Furthermore, an Arable Plants Group has been set up under the aegis of the UK BAP process, bringing together experts from the country agencies, conservation NGOs, botanical institutions, the agronomical industry and the farming community.

In order to safeguard these plants we need to find out where they are, the relative importance of the sites they occupy and to implement the right kinds of conservation measures. Criteria which have been used in identifying areas important for plants are introduced and applied where possible, a method which is explained more fully on page 10.

Whilst this publication provides a brief analysis of existing data and has identified 105 sites of national and European importance to date, it has been principally written to raise awareness about the arable landscape as a whole, and to encourage field workers to identify new sites of potential value, as a first key step towards securing a long-term future for this most threatened element of the British flora. 1 Section 1 WOODFALL WILD WOODFALL IMAGES

A field of blue Cornflower in France: fine displays of formerly common species such as this are a very rare sight in the British landscape today. Important Arable Plant Areas WOODFALL WILD WOODFALL IMAGES

Cornflower (Centaurea cyanus) - the distribution of this very rare species has been severely compromised as a result of deliberate introductions.

1. Introduction For some 6000 years, arable fields have presented one of the most vibrant elements of the British landscape, bright with yellow corn marigolds, red poppies and blue cornflowers. As the hunter-gatherer lifestyle increasingly gave way to an agricultural way of life from 4000 BC onwards - based on cultivated crops and domesticated stock - so a range of annual plants that thrive on frequent disturbance made use of this new, man- made habitat to colonise - in form of the arable field.

Over 150 members of the British flora are characteristic of the arable environment, sharing the same ecological niche as the crop plants among which they grow. Whilst many are now regarded as ancient introductions into Britain, their distribution in this country reflects complex geological, climatic and management factors, so that arable communities in the oceanic south-west are vastly different from those of the East Anglian chalk, for example. Considered by many as fly-by-night colonists, arable plant communities and species show a surprisingly high fidelity to particular sites, so much so that many populations of rarer species have been recorded from particular fields for decades or even centuries.

Arable plants also have a particular resonance in cultural terms. Their history in the UK is intimately tied to our own history, such that their fortunes reflect the rise and fall of arable farming over time, and changes in the way we manage the arable landscape. Once the bane of the arable farmer’s life, today they represent our single most threatened group of plants in the British flora, even though a staggering seven million hectares - approaching 30% - of the British land surface is under cultivation.

3 Section 2

2.The rise and fall of arable plants

The New Atlas of the British and Irish Flora, published in 2002, highlights more clearly than ever just how badly arable plants have fared during the second half of the twentieth century. Of the 30 vascular plant species that have shown the greatest relative decline across Britain between the 1930-69 and 1987-99 recording periods, no fewer than 18 are characteristic of arable and other cultivated ground (Table 1). This decline reflects those observed in other European countries: many species that are of particular concern in Britain are also declining rapidly throughout the whole of their European range.

Yet in spite of being the most critically threatened group of plants in Britain today, arable plants have received little attention from nature conservationists until very recently. As a result the arable community remains the least studied of any plant habitat in Britain at the present time. Fortunately conservationists are increasingly recognising the importance of arable plants and the role they play in the conservation of the British flora and fauna. Twelve species receive full protection under Schedule 8 of the Wildlife and Countryside Act (plus amendments), whilst a total of 12 vascular plant species, plus a further five bryophytes, have been recognised as priority species under the UK Government’s Biodiversity Action Plan (Table 2). Of equal importance is the fact that the arable habitat represents part of the Cereal Field Margins Priority Habitat, and has been the subject of its own Habitat Action Plan since the mid 1990s, whilst several local biodiversity action plans emphasise the importance of this habitat (e.g. Purbeck Biodiversity Action Plan 1998).

These levels of decline are reflected by the new assessment of the threat status of Britain’s vascular plant flora (Cheffings & Farrell 2005), and supplementary surveys. No fewer than seven species are regarded as extinct as arable plants in Britain (although may occur as casuals on occasion), whilst a further 54 species are considered threatened. DAVID NOTON/NATURE PICTURE LIBRARY NOTON/NATURE DAVID

The modern arable landscape, devoid of virtually all arable plants.

4 Important Arable Plant Areas

Table 1. Declines of some arable species during the 20th century (Preston et al., 2002, data presented here covers Britain, excluding Ireland & Channel Isles)

No. of No. of Change 10-km sqs.: 10-km sqs.: index total 1987-1999

Caucalis platycarpos — — -7.86 IMAGE BOB GIBBONS/NATURAL

Galium tricornutum 386 12 -4.78

Bupleurum rotundifolium 287 13 -4.58

Chenopodium urbicum 239 10 -4.57

Ranunculus arvensis 824 157 -3.77

Arnoseris minima 83 1 -3.72

Scandix pecten-veneris 780 164 -3.65

Galeopsis angustifolia 616 91 -3.31

Bromus arvensis 203 11 -3.15

Avena strigosa 270 26 -3.01

Silene gallica 455 82 -2.78 Unlike many rarer arable plants, Scleranthus annuus 991 314 -2.68 the Large-flowered Hemp-nettle ( speciosa) is more Anthoxanthum aristatum 93 2 -2.65 abundant in northern and western Torilis arvensis 389 77 -2.56 parts of Britain.

Valerianella rimosa 181 17 -2.55

Spergula arvensis 2467 1803 -2.30

Adonis annua 234 28 -2.19 Note: Records include both native / naturally- occurring archaeophyte populations, as well as Silene noctiflora 686 238 -2.04 intentional introductions

Arable land and bryophytes Five species of bryophyte are listed as UK BAP Priority Species: Arable land has a distinctive bryophyte Bryophytes of Arable Land (SBAL) • Sausage Beard-moss (Didymodon flora, particularly associated with autumn recording scheme was developed under tomaculosus) - c. 8 sites, endemic to and over-wintering stubbles. It was not the auspices of a steering committee Britain and Ireland until the 1960s that the of comprising representation from the British • Starry Earth-moss (Ephemerum many of its characteristic species was Bryological Society, the Centre for Ecology stellatum) - confined to a handful of clarified and for many species their and Hydrology Biological Records Centre, localities in southern England, and Ireland distribution remains poorly recorded. In English Nature, and the Natural History 2000, Ron Porley of English Nature Museum. The Scheme was launched in the • a beardless-moss,Weissia multicapsularis reviewed the current state of knowledge autumn of 2002, with three winters - c. 11 sites since 1950, in south west of arable bryophytes and concluded that (2002/3, 2003/4 and 2004/5) allocated for England and south Wales (and northern “more survey work is needed in both field survey.The findings are currently France) Britain and Ireland to understand the being written up, and bryophytes are not • Beaked Beardless-moss (Weissia distribution, status and occurrence of being considered further here. rostellata) - widely scattered, but declining bryophytes in different crop types and • Spreading-leaved Beardless-moss under various management regimes, (Weissia squarrosa) - widely scattered, but particularly in relation to organic declining farming”.As a result the Survey of

5 Section 2

Table 2 - Britain’s most threatened arable plants

Extinct in UK (EX) Spring Speedwell (Veronica verna) Cornflower (Centaurea cyanus) (EN, Wiggington 1999)* Lamb’s-succory (Arnoseris minima)

Interrupted Brome ( interruptus) Vulnerable (VU) Purple Bugloss (Echium plantagineum) (EN, Thorow-wax (Bupleurum rotundifolium) Stinking Chamomile (Anthemis cotula) Wiggington 1999)

Small Bur-parsley (Caucalis platycarpos) Rye Brome (Bromus secalinus) Western Fumitory (Fumaria occidentalis) (reassessed as LC, Cheffings & Farrell 2005)* Downy Hemp-nettle (Galeopsis segetum) Nettle-leaved Goosefoot (Chenopodium murale) Purple Ramping-fumitory (Fumaria

W purpurea) (reassessed as LC, Cheffings & Extinct in arable habitats Corn Marigold (Chrysanthemum segetum)* Farrell 2005)* (listed as Critically Endangered by Common Ramping-fumitory (Fumaria Cheffings & Farrell, 2005) muralis ssp. neglecta) Martin’s Ramping-fumitory (Fumaria reuteri) (EN,Wiggington 1999)8 Narrow-leaved Cudweed (Filago gallica)† Small-flowered Fumitory (Fumaria parviflora) False Cleavers (Galium spurium) (E, Perring Darnel (Lolium temulentum)† Few-flowered Fumitory (Fumaria vaillantii) & Farrell 1983)†

Large-flowered Hemp-nettle (Galeopsis Smaller Tree-mallow (Lavatera cretica) W Critically Endangered (CR) speciosa)* (V, Perring & Farrell 1983)

Upright Goosefoot (Chenopodium urbicum) Henbane (Hyoscamus niger) Field Cow-wheat (Melampyrum arvense) 8 Narrow-leaved Hemp-nettle (Galeopsis Smooth Cat’s-ear (Hypochoeris glabra) (EN,Wiggington 1999) angustifolia)* Wild Candytuft (Iberis amara) Greater Hay-rattle (Rhinanthus † 8 Corn Cleavers (Galium tricornutum)* angustifolius) (VU,Wiggington 1999) Yellow Vetchling (Lathyrus aphaca) Corn Buttercup (Ranunculus arvensis) Cut-leaved Germander (Teucrium botrys) Weasel’s-snout (Misopates orontium) (VU,Wiggington 1999)8 Shepherd’s Needle (Scandix pecten-veneris)* Mousetail (Myosurus minimus) Breckland Speedwell (Veronica praecox) Cat-mint (Nepeta cataria) (E, Perring & Farrell 1983) Endangered (EN) Prickly Poppy (Papaver argemone) Pheasant’s-eye (Adonis annua) Night-flowered Catchfly (Silene noctiflora) Ground Pine (Ajuga chamaepitys)8 Corn Spurrey (Spergula arvensis) Corn Chamomile (Anthemis arvensis) Perfoliate Penny-cress (Thlaspi perfoliatum)8* Red-tipped Cudweed (Filago lutescens)8* Slender Tare (Vicia parviflora) Broad-leaved Cudweed (Filago pyramidata)8*

Corn Gromwell (Lithospermum arvense) Additional rare arable species Notes: 8 Grass-poly (Lythrum hyssopifolium) (see Appendix I) EX = species extinct in UK CR = Critically Endangered Annual Knawel (Scleranthus annuus) Corncockle (Agrostemma githago) (EX, EN / E = Endangered VU / V = Vulnerable Small-flowered Catchfly (Silene gallica)* Wiggington 1999) LC = Least Concern Spreading Hedge-parsley (Torilis arvensis)* Hairy Mallow (Althaea hirsuta) (EN, † = Extinct as arable species (though present as Wiggington 1999)8 casuals on occasion) Narrow-fruited Cornsalad (Valerianella 8 = species fully protected through listing on Schedule 8 of the Wildlife & Countryside Act 1981 (plus dentata) Small Alison (Alyssum alyssoides) (E, Perring & Farrell, 1983)8 amendments) Broad-fruited Cornsalad (Valerianella rimosa)* * = UK BAP Priority Species Annual Vernal-grass (Anthoxanthum *W = Section 74 species in Wales only 8 Fingered Speedwell (Veronica triphyllos) aristatum) (E, Perring & Farrell 1983)† Species selection: For a rationale to the listing of species included above, refer to Appendix I.

6 Important Arable Plant Areas

Reasons for declines A wide range of changes to agricultural practices has been blamed for the decline of many arable plant species. Amongst the most significant are: • the widespread use of herbicides • efficient seed cleaning techniques • the massive increase in use of fertilisers (particularly nitrogen) • the development of high-yielding crop varieties • changes in crop rotations (e.g. shift from spring to autumn cultivation) • loss of certain crop types (e.g. rye and ) • loss of over-wintered stubbles and summer fallows • effective field drainage • the removal of field boundaries and the loss of relatively unintensively-farmed field margins BOB GIBBONS/PLANTLIFE BOB GIBBONS/NATURAL IMAGE BOB GIBBONS/NATURAL BOB GIBBONS/NATURAL IMAGE BOB GIBBONS/NATURAL

Above left Hairy Mallow (Althaea hirsuta), a neophyte species possibly introduced into Britain after 1500, but of conservation concern. Above middle Pheasant's-eye (Adonis annua), now considered Endangered, and one of the 30 fastest declining flowering plants in Britain. Above right Narrow-leaved Hemp-nettle (Galeopsis angustifolia): Critically Endangered and listed as a priority species on the UK Government's Biodiversity Action Plan.

7 Section 3

For the first time for over fifty years, 3. Conserving arable plants: arable plants are at the centre of conservation efforts in the farmland a way forward environment, with significant resources being actively directed at In spite of the great improvements in the quality and extent of our knowledge of the their conservation. Two initiatives status of these species in recent years, they remain a difficult group of plants to survey, look set to deliver significant arable and some species remain poorly understood. Sites are often on private land, presenting plant conservation gains over the difficulties of access, and additionally arable plant populations are subject to great coming decade. fluctuations in diversity of species from year to year, depending on the cropping management regime and climatic conditions. Cereal Field Margins Habitat Action Plan A number of recent studies have highlighted the richest areas for arable plants at the Significant targets for the delivery of country level or in Britain overall. English Nature has identified the 18 richest Natural species-rich cultivated arable margins Areas for arable plant diversity in England, each with over 50 arable plant species (Porley are in the process of being agreed 1997 - Map 2). This assessment has been refined by the Biological Records Centre, amongst government agencies and which has identified key 10-km squares across Britain as a whole for 66 rare and conservation NGOs. The two most declining arable species based on data from the New Atlas of the British and Irish Flora (Map 1). significant draft targets for arable Whilst the above analyses have played a key role in identifying the general areas where plant conservation would be: conservation action would be most valuable, they remain insufficiently precise for • Expand the area of cultivated, targeted conservation action at the farm or even field level. Accordingly, a clear unsprayed field margins (from 8,859 methodology for identifying key sites is urgently required, to ensure that rare species and ha in 2005 to 16,000 ha by 2010). species-rich assemblages are adequately conserved in their natural and cultural setting.

• Achieve favourable condition on an Although efforts have been made to locate some of the most important sites in the past increasing proportion of the (e.g. Smith 1986,Wilson 1990, Lock & Wilson 1994), these listings are by no means resource of cultivated, unsprayed comprehensive, nor do they assess the relative conservation value of different sites. margins (50% by 2010, 75% by 2015). With the increasing interest in the conservation of arable plants,‘new’ sites are being discovered annually, and new information is discovered about known locations. Entry Level & Higher Level Stewardship Stewardship schemes offer the most significant mechanism for delivering the on-site conservation of significant arable plant sites, inasmuch as they offer payments for farmers willing to establish cultivated arable margins without resorting to the use of herbicides and fertilisers. Both Entry and Higher Level Stewardship schemes offer options that favour arable plant communities, e.g. overwintered stubbles, fallows, conservation headlands and cultivated uncropped margins.

Map 1: Number of selected uncommon / declining arable species in 10-km squares in the England, Scotland and Wales

8 Important Arable Plant Areas

If adopted widely, six metre wide unsprayed, cultivated margins and other Environmental Stewardship options may

PETER WILSON/WOODFALL WILD PETER WILSON/WOODFALL IMAGES reverse a century of catastrophic decline amongst arable plant populations.

Here we present a methodology for assessing arable sites based on the presence of threatened species and/or exceptional assemblages of arable species derived from the wider Important Plant Areas (IPA) model (see box, page 10). The criteria present thresholds that should allow botanists, conservationists and others to instantly assess the value of a site - be it of county, national or European importance. At the present time the thresholds for site selection should be regarded as provisional, and may need to be reassessed as our knowledge of the arable plant resource improves. Nevertheless, whilst this should be seen as a working document, it is hoped that the criteria presented will prove a valuable tool to:

• assess the current value of arable sites, for example for land acquisition, formal designation (e.g. as County Wildlife Sites), or protection through the planning process

• provide farmers and conservationists with a methodology to identify key fields for entry into Environmental Stewardship and other conservation schemes, based on past or present records

• provide farm advisors with a means of assessing the effectiveness of stewardship and other conservation payments at arable sites.

This report does not take account of the growing - and worrying - practice of sprinkling seed of cultivated stock of arable plants in the British landscape. Instead, two important facts should be stressed: firstly, many species show a remarkably strong fidelity to individual sites or particular landscapes - e.g. English Nature’s Natural Areas and Defra’s Joint Character Areas - and conservation efforts should strive to maintain this regional diversity. Furthermore, most (though not all) arable plants have a remarkable ability to recolonise ‘lost’ sites from dormant buried seed - how much more rewarding to bring species back from the brink under such circumstances!

9 Section 4

The Important 4. Criteria for the selection Plant Area concept of Important Arable Plant Areas A current focus for plant conservation is the Important Plant Areas (IPA) (IAPAs) programme, designed to identify a The Important Arable Plant Areas (IAPAs) criteria presented here have been adapted network of the key botanical sites and developed from the three criteria identified in Plantlife International’s site selection across Europe. The concept has now manual for European IPAs (Anderson, 2002) and reproduced left. These seek to select been widely adopted in Europe, and is sites based on the presence of (a) particular threatened species, (b) exceptional plant increasingly finding favour more widely assemblages, or (c) priority habitats of particular importance to botanical science. across the globe as a significant mechanism for identifying exceptional Site status botanical sites and prioritising Whilst the European IPA process simply selects sites of international importance, the conservation action. The IPA methodology is here used to highlight arable sites in the UK of three levels of importance: mechanism is also fundamental to the • Sites of European importance: sites that are identified as being of European delivery of Target 5 of the Global importance on account of their arable vascular plant interests alone, and which should Strategy for Plant Conservation be considered for inclusion within the UK’s IPA contribution to the European network (adopted at the sixth meeting of the of IPAs. The UK listing is due for publication in 2006. Conference of the Parties to the Convention on Biological Diversity), • Sites of United Kingdom importance: additional sites of national importance for their which calls for the protection of 50% arable plant interests. of the most important areas for plant • Sites of county importance: a shadow listing of sites that are of high regional importance, diversity by 2010. which may, with further detailed recording, prove to be of national importance.

Rich arable plant communities perhaps represent the one habitat in Britain that have not Definition of an Important Plant been the subject of a detailed field-by-field assessment. Furthermore, at the European Area level few if any widespread, yet often catastrophically declining, arable plant species have An Important Plant Area (IPA) is a been highlighted in international red lists. Accordingly, it is difficult to provide a definitive natural or semi-natural site exhibiting set of European criteria here - and it may prove necessary to review certain criteria in exceptional botanical richness and/or due course. supporting an outstanding assemblage of rare, threatened and/or endemic Criteria categories plant species and/or vegetation of high Criterion A - threatened species - allows for the selection of sites based solely on the botanic value. occurrence of threatened arable species listed in recognised national, European or global red lists. At the present time no British arable plant species are recognised as Three basic principles for IPA threatened at a European level, so no arable sites here currently qualify at the European identification level under criterion A. However, this may change in the fullness of time as regional red Criterion A The site holds significant data books are revised to take account of the catastrophic decline that many arable populations of one or more species species are currently undergoing. that are of global or European At UK level, Criterion A allows for the selection of key sites of threatened and/or conservation concern protected species. For threatened species (i.e. Critically Endangered, Endangered and Criterion B The site has an Vulnerable species), plus additional UK BAP priority species (namely Fumaria occidentalis exceptionally rich flora in a European and F. purpurea), up to 30 ‘best’ arable sites should be selected. context in relation to its biogeographic zone All additional populations of threatened species, plus county rarities, should be selected as being of county importance. Criterion C The site is an outstanding example of a habitat type of global or European plant conservation and botanical importance

10 Important Arable Plant Areas

Criterion B - outstanding assemblages - utilises the same methodology for identifying sites of county, UK and European importance, viz. a scoring system that tallies the Table 3 Scoring categories for weighted individual score of each of the species present according to their rarity and arable plant species. decline across Britain. Score Status

The basic listing of arable species has been drawn from PLANTATT:Attributes of British and 9 Threatened - Critically Irish Plants (Hill et al. 2004), which provides the most comprehensive listing of species Endangered (CR) characteristic of arable land currently available. This has been supplemented with a selection of additional species considered to occur occasionally as characteristic 8 Threatened - Endangered members of the arable flora (although are often equally typical of non-arable habitats). (EN / E)

Individual species scores - ranging between 1 (common) to 9 (rarest and most 7 Threatened - Vulnerable threatened) - have been assigned to arable plants based on (i) their current occurrence (VU / V) within 10-km squares; and/or (ii) their recent decline (based on the information 6 Near threatened (NT) contained in The New Atlas of the British Flora (Preston et al., 2002)); and/or (iii) their current species threat status (based on information contained in Cheffings & Farrell 5 Additional Nationally 2005, supplemented by that in Wigginton (1999) and Perring & Farrell (1983) - for Scarce: 16 to 50 10-km choice of species refer to Appendix I). The scoring categories are detailed in Table 3. squares; or 51 to 100 10- km squares, change index The outstanding assemblage assessment methodology presented here is based on the less than -1.0 cumulative total of the weighted scores of species present at each site, allowing the comparison of the relative nature conservation value of different sites. Provisional 4 Additional Nationally Scarce: 51 threshold scores have been proposed for sites of county, national and European to 100 10-km squares, change importance (Table 4). In addition, the scoring system recognises that arable communities index greater than -1.0 on a particular geological substrate may consistently score either more or less than 3 Species of local concern: equally valued communities on a different substrate. Accordingly the thresholds are 101 to 500 10-km squares varied for three broad geological categories: 2 Species of local concern: • sandy and other free draining non-calcareous soils (particularly in western and 501 to 1000 10-km squares northern parts of the UK) • heavier clay soils (particularly in the Midlands and East Anglia) 1 Species of local concern: 1001 • dry calcareous soils on chalk and limestone (particularly southern and eastern England) to 1500 10-km squares, change index less than 0.0 (i.e. negative) It must be emphasised that the thresholds presented here are provisional and may require refinement following further field-testing and evaluation. See appendix II for score assigned to individual species.

Table 4. Provisional threshold scores for assessing the conservation importance of arable plant sites.

Chalk and Clays Sands and freely limestone- draining acidic derived soils soils

(excluding clays) IMAGE BOB GIBBONS/NATURAL

European importance 90+ 70+ 70 + National importance 45 - 89 30 - 69 35 - 69 County importance 30 - 44 20 - 29 20 - 34

Rare and specialised: Grass-poly (Lythrum hyssopifolium) is largely confined to seasonally-flooded hollows in arable fields in Britain.

11 Section 4

Criterion C - priority habitats - the diversity of arable plant communities and vegetation types has been poorly studied, both in Europe and the United Kingdom. Accordingly, at the present time, it is inappropriate to choose Important Arable Plant Areas based on the occurrence of particular rare arable habitats. This should be reviewed in the fullness of time.

The criteria used for selection of Important Arable Plant Areas are shown below.

Table 5. Criteria for selection of Important Arable Plant Areas

Criterion A: Criterion B: Threatened species Species richness

Sites of Select: Select: European All viable arable sites thought, or inferred, to All arable sites meeting the following thresholds importance contain 5% or more, OR the five ‘best’1 sites according to the weighted evaluation scoring system (whichever is most appropriate), of the UK for arable species assemblages: 2 population of species listed as threatened on: • chalk & limestone derived soils: 90+ • IUCN global red lists • clay soils:70+ • European IUCN red lists • sands & freely-draining acidic soils: 70+ • EU habitats Directive Annexes IIb or IVb • Bern Convention Appendix I and/or endemic or near endemic3 species listed as threatened on UK red lists.

[Note: currently no sites in the UK meet this criterion]

Sites of UK Select: Select: importance All viable arable sites thought, or inferred, All arable sites meeting the following thresholds to contain 3% or more of the UK population, according to the weighted evaluation scoring system OR for arable species assemblages: 1 the 30 ‘best’ sites (whichever is most • chalk & limestone derived soils: 45-89 appropriate), of species listed as Critically • clay soils:30-69 Endangered, Endangered or Vulnerable in approved UK red lists; and/or UK BAP priority species • sands & freely-draining acidic soils: 35-69

Sites of Select: Select: county All additional populations of species listed as All arable sites meeting the following thresholds importance threatened2 in approved UK red lists; and/or as a UK according to the weighted evaluation scoring system BAP priority species (not included above); for arable species assemblages: AND/OR • chalk & limestone derived soils: 30-44 All populations of species recorded in three or • clay soils:20-29 fewer localities in a specific county since 1995. • sands & freely-draining acidic soils: 20-34

Notes: 1. Best sites are those of most significance for the long-term survival of the species in the UK, and are principally assessed on overall size of the population and its long-term viability. 2. Threatened species must be listed as Critically Endangered (CR), Endangered (EN) or Vulnerable (VU) according to the 2000 IUCN red list categories (IUCN 2001). 3. Near endemic species is a plant that is found in a very limited range within Europe. “For practical purposes this may be defined as a species that has more of its range within one country and occurs in no more than 2-3 countries in total, or that occurs only within one geographical unit, such as the Carpathians” (Anderson 2002)

12 Important Arable Plant Areas SIMON WILLIAMS

Farm visits and other training events are increasing awareness of the conservation importance of arable plants amongst agronomists, farmers and conservationists.

Notes on applying criteria Site introductions from wild flower mixes, or unfavourable season, most will reappear It can be difficult to define a site. The as casuals of garden origin, should be when conditions improve. term here is interpreted broadly, and can discounted as they are not considered Choice of species include single fields, groups of fields to be as valuable in nature conservation Unique amongst wild plant habitats in within a farm, a whole farm, or a larger terms as ‘naturally’ occurring populations. Britain, the arable community includes area including several fields of Additionally, natural yet casual populations valued species that are considered importance. arising from disturbance associated with native, archaeophyte (introduced prior building and other construction works Arable land to 1500) or neophyte (introduced post- should be discounted. The definition of arable land is treated 1500). Appendix I provides a rationale broadly here, and includes not just the Since arable species are highly sporadic for the species chosen here as indicators regularly cultivated fields drilled with in their occurrence, a single survey may of important arable habitats. typical field crops such as cereals, only give a partial picture of the floristic Viable populations and sites linseed, rape, potatoes, maize or root diversity in an arable field, so a In assessing threatened plant populations crops, but also field-grown horticultural composite list recorded over several according to Criterion A, site recorders crops (e.g. bulb fields), and less regularly years may be used. For practical need to assess the long-term viability of cultivated field edges and fallows. purposes records dating back to 1985 the population. A population is may be considered, as most arable plant Arable plants and populations considered extant if it has been recorded species benefit from seeds that remain Only non-casual, arable populations of at least once since 1985, and viable if the viable, yet dormant, in the soil seed bank naturally-occurring species should be total cumulative population has over decades. So whilst they may appear included within any site assessment. numbered over 100 individuals during to be absent during a particular Populations arising from deliberate the post-1985 period.

13 Section 5

5. Initial findings

Plantlife International has drawn up a preliminary inventory of key sites based on our existing knowledge of selected areas and particular sites. To date, a total of 133 sites have been assessed as being of county or greater importance. Six sites of European importance have been identified: these should be considered as candidates for inclusion within the inventory of Important Plant Areas in the UK (Map 2). A further 99 sites of national importance are listed, but it is likely that this tally will increase as additional sites of county importance are reassessed and ‘upgraded’ as a result of additional field survey.

The sites of national and European importance are scattered across much of Britain from Cornwall to Orkney, but the majority lie in southern and eastern England, to the south of a line between the Bristol Channel and the Wash. Not surprisingly, there is a strong correlation between the location of important arable sites and 18 key Natural Areas for arable plants as identified by English Nature: some 83% of the provisional IAPAs lie within these richest Natural Areas. The provisional distribution of Important Arable Plant Areas is shown on Map 2.

Mwnt Fields, Ceredigion SN15 West Pentire Fields, Porth Joke, SSSI Cornwall SW76 Mwnt Arable Fields cover approximately National Trust property 20 hectares in three blocks, primarily on Noted for its dramatic displays of poppies glacial sands and clays overlooking and Corn Marigold, the 16 hectares of Cardigan Bay. Many years of study have fields on the thin acid soils on the cliffs of identified an exceptional flora of local and the north Cornish coast have been of very rare species including Annual Knawel, high nature conservation importance over Small-flowered Catchfly, Narrow-fruited the past few decades following the National Cornsalad, Corn Marigold and Weasel’s- Trust’s decision to manage the land ‘in snout, making this probably the single house’ for its arable flora. Shepherd’s- richest complex of arable fields for plants needle, Small-flowered and Night-flowering in Wales. A long history of arable Catchfly,Western Ramping-fumitory, Corn cultivation, in part, explains the species Marigold and Weasel’s-snout are amongst richness, but at the present time the fields the rarer species present. Problems lie under a range of management. The associated with the proliferation of fields form the first Site of Special perennial weeds is being addressed through Scientific Interest selected solely for the a programme of occasional, controlled arable flora and fauna to be notified in weedkiller application. Wales.

Map 2. 133 provisional Important Arable Plant Areas of the UK overlaid upon the 18 key Natural Areas for arable plants

14 Important Arable Plant Areas

Fivehead Fields, Somerset ST32 Whiteparish,Wiltshire SU22 SSSI, Somerset Wildlife Trust reserve No formal protection Fivehead Arable Fields comprise 25 Fields around Whiteparish (south-east hectares of arable land on fertile Wiltshire) are of exceptional importance calcareous clays in south Somerset. They for their rich flora, in part reflecting the have long been noted for their rich flora mixed chalky and sandy soils at the of rare arable plants, including Corn boundary of the heathlands of the Gromwell, Corn Buttercup, Narrow- Hampshire Basin and the elevated fruited and Broad-fruited cornsalads, Wiltshire downs to the north. Notable Shepherd’s-needle, and Spreading Hedge- species of the chalky soils include parsley. The site is notified as a Site of Pheasant’s-eye, Corn Gromwell, Spreading Special Scientific Interest and has been Hedge-parsley, Shepherd’s-needle, Fine- owned by the Somerset Wildlife Trust leaved Fumitory and Narrow-fruited since 1992. Early problems associated with Cornsalad, whilst Weasel’s-snout and the spread of pernicious weeds, combined Lesser Quaking-grass are more typical of with the difficulty in working the fields’ the acid sands. Whilst the fields are in heavy soils, have largely been overcome, private ownership, the arable flora and today the fields represent an excellent interests are conserved through example of arable plant conservation. stewardship agreements.

Ranscombe Farm, Kent TQ76 Longparish, Hampshire SU44 SSSI, Plantlife International reserve No formal protection Situated on the chalk of the North Fields around Longparish, located at the Downs, immediately west of the Medway edge of the River Test Valley, within the Gap, the c.4 hectare Kitchen Field at central Hampshire chalk downs have been Ranscombe has long been famed amongst noted for their rich arable weed flora for a botanists as one of the richest sites for number of decades. The arable flora here arable plants in the UK. Notable plants epitomises that of the southern chalklands, include the UK’s largest population of and includes many rare species including Broad-leaved Cudweed, the first British Pheasant’s-eye, Red Hemp-nettle, Spreading locality for Hairy Mallow (discovered in Hedge-parsley, Shepherd’s-needle, Fine- 1792), an abundance of Corncockle leaved Fumitory and Narrow-fruited (possibly natural here, but appeared in Cornsalad. The land is under private 2000 following deep ploughing), and local ownership, but does not, as yet, receive any and rare species such as Ground Pine, form of protection. Rough Poppy, Night-flowering Catchfly and Blue Pimpernel. Whilst the site is fully protected, and is subject to a management agreement, in recent years perennial weeds such as Coltsfoot, Couch and Creeping thistle have become problematic. This, and a reduction in the diversity of management practices, has resulted in the decline of certain species.

15 Section 5

Rare species such as Ground Pine and Broad-leaved Cudweed reappeared from buried seed in just one season after eliminating herbicide usage at Ranscombe Farm (above), Plantlife's nature reserve in Kent . BOB GIBBONS/PLANTLIFE

How you can help The criteria presented here have been importance. To this end,Plantlife has enter their land into stewardship and produced with the aim, above all, of established an arable plants database in other conservation schemes. stimulating further survey in the arable 2002, with generous support from Additional site information can be landscape, allowing surveyors and English Nature and the Esmée Fairbairn recorded using the pull-out form conservationists to assess newly discovered Charitable Foundation. The database included within the centre pages of this sites according to transparent criteria. stores information about key sites, publication, and should be sent to allowing a full assessment of the relative Even though 105 sites of national and Plantlife International, 14 Rollestone values of candidate sites. It is hoped that European importance have been Street, Salisbury,Wiltshire, SP1 1DX. over time this will develop into a identified, the arable landscape of Britain comprehensive database of Britain’s For further information on Britain’s remains vastly under-recorded, and most important arable landscapes from a arable plants refer to the references at Plantlife International would welcome plant conservation point-of-view - acting the end of this report, or visit the Arable any information about any sites that may as a vital link between botanists and Plants Group website: prove to be of national or European those actively encouraging farmers to www.arableplants.org.uk

16 Important Arable Plant Areas

References and further reading

Anderson, S. (2002). Identifying Important Plant Areas. Plantlife, London.

Cheffings, C.M. & Farrell, L. (2005). Species Status, Report No. 7:The vascular plant red data list for Great Britain. Joint Nature Conservation Committee, Peterborough.

Eggers,T. & Wicke, G. (2000). Experiences of the management for conservation of endangered arable weeds in Germany. In: Fields of Vision,a Future for Britain’s Arable Plants, eds PJ Wilson & M King. RSPB.

Gulliver, R.L. & Gulliver, M.C. (2000). The arable plants of the Hebridean island of Colonsay. In:Wilson, P.J.& King, M. (eds.). Fields of Vision,a Future for Britain’s Arable Plants. Royal Society for the Protection of Birds, Sandy, Bedfordshire.

Hill, M.O., Preston, C.D. & Roy, D.B. (2004). PLANTATT:Attributes of British and Irish Plants. NERC Centre for Ecology and Hydrology, Monks Wood.

IUCN - the World Conservation Union (2001). IUCN red list categories and criteria: version 3.1. IUCN Species Survival Commission, IUCN, Gland, Switzerland / Cambridge, UK.

Kay, S. (2000). Survey and audit - problems and solutions. In: In:Wilson, P.J.& King, M. (eds.). Fields of Vision,a Future for Britain’s Arable Plants. Royal Society for the Protection of Birds, Sandy, Bedfordshire.

Lock, L. & Wilson, P.J.(1996). A botanical audit of arable farmland in SW England. Report produced in association with the Game Conservancy and Plantlife.

Lockton,A. (2002). BSBI Arable Weed Survey. Botanical Society of the British Isles,

Perring, F.H. & Farrell, L. (1983). British Red Data Book: 1 Vascular Plants (2nd ed.) Royal Society for Nature Conservation, Lincoln.

Perring, F.H. & Walters, S.M. (1962). The Atlas of the British Flora. Nelson, London.

Porley, R. (1997). Rare and scarce vascular plants and bryophytes in Natural Areas Research Report No 267, English Nature, Peterborough.

Preston, C.D., Pearman, D.A. & Dines,T.D. (2002). New Atlas of the British and Irish Flora. Oxford University Press.

Rich,T.C.G. & Woodruff, E.R. (1996). Changes in the vascular plant floras of England and Scotland between 1930-60 and 1987-88: the BSBI monitoring scheme. Biological Conservation, 75: 217-229.

Rodwell, J.S. (1991). British Plant Communities,Volume 1. Woodlands and Scrub. Cambridge University Press.

Rodwell, J.S. (2000). British Plant Communities,Volume 5. Maritime Communities and Vegetation of Open Habitats. Cambridge University Press.

Smith,A. (1986). Endangered Species of Disturbed Habitats. CSD Report No. 644. Nature Conservancy Council, Peterborough.

Stewart,A., Pearman, D.A. & Preston, C.D. (1994). Scarce Plants in Britain. JNCC, Peterborough.

Wigginton, M.J. (1999). British Red Data Books 1,Vascular Plants. JNCC, Peterborough.

Wilson, P.J.(1990). The Ecology and Conservation of Rare Arable Weed Species and Communities. University of Southampton.

Wilson, P.J.& King, M. (2003). Arable Plants - a field guide. English Nature & WildGuides, Old Basing, Hampshire, UK.

Wilson, P.J.(in prep.). Important Arable Plant Areas: criteria for the Assessment of 17 Arable Sites. Important Arable Plant Areas

Appendix I

The choice of species: natives vs. introductions The New Atlas of the British and Irish Flora (Preston et al., 2002) categorised alien plant species in two categories, according to the date of their introduction into the United Kingdom. Archaeophytes are species known to have been introduced before 1500, whilst neophyte species are thought to have been introduced subsequent to this date. The vast majority of arable plant species were considered by this publication to be introduced, with a significant number considered to be relatively recent arrivals (i.e. neophytes). In their reassessment of the threat status of all species in the British flora, Cheffings & Farrell (2005) considered only native and archaeophyte species. This report, however, has chosen to retain a number of key neophyte species as being of nature conservation value for two significant reasons. On the one hand, as a conservation tool this report takes a precautionary approach, recognising that whilst the first documented occurrence of each species post-dated 1500, this is not categorical proof that the species had not been present before this date. Indeed some species - for example Fumaria reuteri, Lavatera cretica, Melampyrum arvense,Teucrium botrys - have been considered native in many or indeed most botanical publications published since 1950 (although it should be noted that in some instances they had been regarded as aliens in earlier publications). Equally important, this report recognises that unique amongst Britain’s plant habitats, the arable landscape is composed in good part of introduced species. Certain neophytes remain highly localised and distinctive members of unique arable weed floras (for example, Ranunculus muricatus and Veronica praecox are confined to the Isles of Scilly and Breckland respectively) - these are listed as ‘Additional rare arable plants’ above.

In assigning individual species scores (see page 11 and appendix II), in the absence of a recent reassessment of the threats these species face, the status of species from two earlier red lists has been utilised (Perring & Farrell 1983 and Wiggington 1999).

Agrostemma githago - Wigginton (1999) considered this species to be Extinct in the United Kingdom, but recent evidence suggests that the species does have the ability to survive in the seed bank under exceptional circumstances (typically when deeply buried), and a few populations have recently been discovered that are thought to be natural. However, the picture has been severely compromised by an abundance of poorly documented introductions that have taken place in recent decades. In the absence of conclusive information about the current status of the species in the UK, Cheffings & Farrell (2005) placed the species on ‘waiting list’, acknowledging that “research needs to be undertaken to clear up.....distributional.....problems”. However, following the precautionary approach, this document retains Corncockle as a rare species of note, and where there is strong or conclusive evidence that an arable population has reappeared naturally, then this should be treated as if the species were Critically Endangered. However, in assessing populations caution should be exercised before pronouncing on the natural vs. recently introduced status of a population.

Centaurea cyanus - the 2005 red list (Cheffings & Farrell 2005) assigns Cornflower to the Least Concern category, reflecting the fact that during this reassessment of the UK flora, it was impossible to differentiate between the rare natural occurrences of this archaeophyte species and the multitude of deliberate introductions. Nevertheless, the consensus amongst botanists is that the species remains very rare as a naturally occurring, and often long-standing, species of arable field. To reflect this fact, the current criteria have retained the earlier Endangered status for the species (Wiggington 1999), but this should only be applied to sites where there is strong evidence that the population is natural and viable

18 Important Arable Plant Areas

Appendix II Species scores

Species Species Species Species score score Adonis annua 8 Euphorbia platyphyllos 3 Agrostemma githago 9 Filago gallica 9 Ajuga chamaepitys8Filago lutescens 8 Alopecurus myosuroides 2 Filago pyramidata 8 Althaea hirsuta 8 Filago vulgaris 6 Alyssum alyssoides 8 Fumaria bastardii 2 Anagallis arvensis ssp. foemina 5 Fumaria capreolata 3 Anchusa arvensis 1 Fumaria densiflora 3 Anthemis arvensis 8 Fumaria muralis ssp. neglecta 7 Anthemis cotula 7 Fumaria occidentalis 5 Anthoxanthum aristatum 8 Fumaria parviflora 7 Anthriscus caucalis 3 Fumaria purpurea 4 Apera interrupta 4 Fumaria reuteri 8 Apera spica-venti 6 Fumaria vaillantii 7 Aphanes australis 1 Galeopsis angustifolia 9 Arnoseris minima 9 Galeopsis segetum 9 Avena strigosa 5 Galeopsis speciosa 7 Brassica nigra 2 Galium spurium 8 Briza minor 5 Galium tricornutum 9 Bromus arvensis 6 Gastridium ventricosum 5 Bromus interruptus 9 Geranium columbinum 2 Bromus secalinus 7 Geranium pusillum 2 Bunium bulbocastanum 6 Holosteum umbellatum 9 Bupleurum rotundifolium 9 Hyoscyamyus niger 7 Camelina sativa 5 Hypochoeris glabra 7 Caucalis platycarpos 9 Iberis amara 7 Centaurea cyanus 8 Kickxia elatine 2 Chaenorhinum minus 1 Kickxia spuria 3 Chenopodium ficifolium 2 Lamium amplexicaule 1 Chenopodium hybridum 3 Lamium confertum 3 Chenopodium murale 7 Lathyrus aphaca 7 Chenopodium polyspermum 2 Lavatera cretica 7 Chenopodium urbicum 9 Legousia hybrida 3 Chrysanthemum segetum 7 Lepidium campestre 3 Descurainia sophia 3 Lithospermum arvense 8 Echium plantagineum 8 Lolium temulentum 9 Erodium cicutarium 1 Lythrum hyssopifolium 8 Erodium moschatum 3 Malva neglecta 2 Erysimum cheiranthoides 2 Melampyrum arvense 8 Euphorbia exigua 6 Mentha arvensis 1

19 Important Arable Plant Areas

Species Species score Mercurialis annua 2 Misopates orontium 7 Myosurus minimus 7 Nepeta cataria 7 Orobanche minor 2 Papaver argemone 7 Papaver dubium ssp. lecoqii 2 Papaver hybridum 3 Petroselinum segetum 3 Polycarpon tetraphyllum 5 boreale 4 Polygonum rurivagum 3 Ranunculus arvensis 9 Ranunculus muricatus 6 Ranunculus parviflorus 3 Ranunculus sardous 3 Raphanus raphanistrum 1 Rhinanthus angustifolius 7 Scandix pecten-veneris 9 Scleranthus annuus 8 Sherardia arvensis 1 Silene gallica 8 Silene noctiflora 7 Sinapis alba 2 Spergula arvensis 7 Stachys arvensis 6 Teucrium botrys 7 Thlaspi perfoliatum 7 Torilis arvensis 8 Torilis nodosa 3 Valerianella dentata 8 Valerianella rimosa 8 Veronica agrestis 1 Veronica polita 2 Veronica praecox 8 Veronica triphyllos 8 Veronica verna 8 Vicia parviflora 7 Vicia tetrasperma 2 Viola tricolor ssp. tricolor 6

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Further copies of this report are available from Plantlife International price £6 (including post and packaging). This report was commissioned as part of Plantlife International’s species recovery programme Back from the Brink, with generous financial support from English Nature and the Esmée Fairbairn Charitable Foundation.

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