Habitat account - Natural and semi-natural grassland formations
6210 Semi-natural dry grasslands and scrubland facies: on calcareous substrates (Festuco-Brometalia)
Background to selection
|Distribution of SACs/SCIs/cSACs with habitat 6210 Semi-natural dry grasslands and scrubland facies: on calcareous substrates (Festuco-Brometalia). Click image for enlarged map.|
Description and ecological characteristics
Festuco-Brometalia grasslands are found on thin, well-drained, lime-rich soils associated with chalk and limestone. They occur predominantly at low to moderate altitudes in England and Wales, extending locally into upland areas in northern England, Scotland and Northern Ireland. Most of these calcareous grasslands are maintained by grazing. A large number of rare plants are associated with this habitat, including purple milk-vetch Astragalus danicus, dwarf sedge Carex humilis, spotted cats-ear Hypochaeris maculata, spring cinquefoil Potentilla tabernaemontani, pasqueflower Pulsatilla vulgaris, bastard-toadflax Thesium humifusum and the Annex II species 1654 early gentian Gentianella anglica, as well as various bryophytes and lichens. The invertebrate fauna is also noteworthy, and includes rarities such as the adonis blue Lysandra bellargus and silver-spotted skipper Hesperia comma.
This Annex I category includes various forms of calcareous grassland referable in European terms to the Mesobromion and Xerobromion alliances. All forms of Festuco-Brometalia grassland comprise mixtures of grasses and herbs, in which there is at least a moderate representation of calcicolous species. The structural and floristic characteristics of the habitat are strongly influenced by climatic factors and management practices, in particular the intensity of grazing. The main sub-types of these grasslands in the UK correspond to the following NVC types:
- CG1 Festuca ovina Carlina vulgaris grassland
- CG2 Festuca ovina Avenula pratensis grassland
- CG3 Bromus erectus grassland
- CG4 Brachypodium pinnatum grassland
- CG5 Bromus erectus Brachypodium pinnatum grassland
- CG6 Avenula pubescens grassland
- CG7 Festuca ovina Hieracium pilosella Thymus praecox/pulegioides grassland
- CG8 Sesleria albicans Scabiosa columbaria grassland
- CG9 Sesleria albicans Galium sterneri grassland
CG2 Festuca Avenula grassland is widely distributed in grazed calcareous pastures throughout the lowlands of England and Wales. Typical Mesobromion calcicoles, such as meadow oat-grass Avenula pratensis, quaking-grass Briza media, common rock-rose Helianthemum nummularium, salad burnet Sanguisorba minor ssp. minor and small scabious Scabiosa columbaria, are well-represented, and are usually accompanied by species with a more Continental distribution, including dwarf thistle Cirsium acaule and squinancywort Asperula cynanchica. Many of the best-known chalk grassland rarities occur in this type of Festuco-Brometalia, and some examples are strikingly species-rich.
CG1 Festuca Carlina and CG7 Festuca Hieracium Thymus grasslands both occur on shallow, sharply-draining soils, and comprise open swards in which the representation of Mesobromion species is significantly reduced. Both communities are characterised by the frequency of mouse-ear hawkweed Hieracium pilosella, wild thyme Thymus praecox and annual/biennial species such as yellow-wort Blackstonia perfoliata and thyme-leaved sandwort Arenaria serpyllifolia. The Festuca Hieracium Thymus community is centred on areas of low rainfall in eastern England, and shows affinities with arid calcareous grasslands of continental Europe. Conversely, the Festuca Carlina community occurs only around the coasts of Wales and southern and western England where the climate is warm and mild, and has affinities to the Xerobromion alliance of southern and central Europe.
Where grazing levels are reduced, Festuco-Brometalia swards typically become dominated by coarse grasses (in particular, downy oat-grass Avenula pubescens, tor-grass Brachypodium pinnatum and upright brome Bromus erectus), and plants of smaller stature become correspondingly scarcer. CG3 Bromus grassland, CG4 Brachypodium grassland, CG5 Bromus Brachypodium grassland, and CG6 Avenula grassland are all widely distributed on chalk and limestone in the English lowlands, and CG3 and CG6 extend locally into Wales. Shrub species, such as hawthorn Crataegus monogyna and blackthorn Prunus spinosa, may become established where grazing is sufficiently light, and may eventually form patches of scrub (e.g. W21 Crataegus monogyna Hedera helix scrub). Grassland-scrub transitions provide important habitats for a wide range of rare and local British species.
On the limestones of northern England, grasslands dominated by Sesleria albicans are locally abundant. In CG8 Sesleria Scabiosa grassland, Sesleria is accompanied by a range of typical Mesobromion species; this community is restricted to Magnesian Limestone at low altitudes in Durham. CG9 Sesleria Galium grassland is more widespread, and occurs at moderate-high altitudes on Carboniferous Limestone in the Pennines and Lake District. The sub-montane character of the vegetation is shown by the reduced frequency of Mesobromion species, and the presence of limestone bedstraw Galium sterneri and other northern/upland species; some stands are enriched with arctic-alpine rarities. Similar Sesleria-dominated grasslands are also found in Northern Ireland.
Most stands of the upland NVC type CG10 Festuca ovina Agrostis capillaris Thymus praecox grassland have a very muted calcicolous component and are not referable to the Festuco-Brometalia. However, a few examples over limestone in Scotland have a significant representation of Mesobromion species, and have therefore been referred to this Annex I type.
Various sub-types of Festuco-Brometalia grassland frequently occur in close association, their distribution being determined by slope, aspect, grazing intensity and recreational pressure. Transitions between calcareous grasslands and heath, acid grassland, scrub and woodland communities are also widespread.
European status and distribution
Semi-natural dry grasslands, which were once widespread in Europe, are now a scarce and threatened habitat. There are no overall estimates available for the extent of this habitat type in Europe as a whole.
UK status and distribution Click to view UK distribution of this habitat
Festuco-Brometalia grasslands occur widely on suitable substrates in England and Wales, but are much more restricted in Scotland and Northern Ireland. The total UK extent of grasslands conforming to this type is probably less than 60,000 ha.
Site selection rationale
Sites have been selected to ensure coverage of the wide ecological variation and geographical range of this habitat. For most of the main sub-types, the largest examples have been selected, although some smaller sites have been included where they represent certain additional variants of the habitat type or have the best conservation of structure and function. For several of the southern sub-types, e.g. CG4 Brachypodium grassland, important sites have been selected as examples of 6211 Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) (*important orchid sites).
A number of sites within the SAC series have well-developed transitions between grassland and heath or scrub (e.g. Craven Limestone Complex, Great Ormes Head, Morecambe Bay Pavements, Peak District Dales).
The selected sites support a large proportion of the total habitat resource remaining in the UK. They are among the best grasslands in the UK for functional integrity as ecological units (i.e. they are judged to be large enough and physically diverse enough to maintain their current biodiversity importance under favourable management). The selected sites are also among the richest grasslands for rare plant and animal species found in the UK, although this was not a primary consideration in site selection.
|Asby contains extensive examples of CG9 Sesleria albicans Galium sterneri grassland in south Cumbria on Carboniferous Limestone hills at altitudes between 230 and 470 m. The grassland occurs in a mosaic with a wide range of other habitats, including 8240 limestone pavements, 7230 alkaline fens, 6410 Molinia meadows and 4030 European dry heaths. A number of rare species are associated with the sub-montane semi-natural dry grassland, including birds-foot sedge Carex ornithopoda and dwarf milkwort Polygala amarella.|
|Barnack Hills and Holes||City of Peterborough|
|his habitat at Barnack Hills and Holes consists largely of CG5 Bromus erectus Brachypodium pinnatum grassland. It supports what is considered to be the largest UK population of the nationally scarce man orchid Aceras anthropophorum. It also supports a rich assemblage of other orchid species, such as fragrant orchid Gymnadenia conopsea, pyramidal orchid Anacamptis pyramidalis and bee orchid Ophrys apifera. The site represents orchid-rich grassland in the northern part of its range, on limestone rather than on chalk.|
|Breckland in East Anglia is the most extensive surviving area of the rare grassland type CG7 Festuca ovina Hieracium pilosella Thymus praecox grassland. The grassland is rich in rare species typical of dry, winter-cold, continental areas, and approaches the features of grassland types in central Europe more than almost any other semi-natural dry grassland found in the UK. The terrain is relatively flat, with few physical variations, but there are mosaics of calcareous grassland and heath/acid grassland, giving rise to patterns of structural variation.|
|Butser Hill is situated on the east Hampshire chalk which forms part of the South Downs. Much of the site consists of CG2 Festuca ovina Avenula pratense grassland. The site has a varied range of slope gradients and aspects which has a strong influence on the vegetation composition. A particular feature of the site is its lower plant assemblage. It has the richest terricolous lichen flora of any chalk grassland site in England, and also supports the distinctive Scapanietum asperae or southern hepatic mat association of leafy liverworts and mosses on north-facing chalk slopes. This association is very rare in the UK and Butser Hill supports the largest known example. The site exhibits various transitions between semi-natural dry grassland, chalk heath, mixed scrub and 91J0 Taxus baccata woods.|
|Castle Hill||Brighton and Hove; East Sussex|
|This chalk grassland consists of a mosaic of calcareous semi-natural dry grasslands, notably CG2 Festuca ovina Avenula pratensis grassland, CG3 Bromus erectus grassland and CG4 Brachypodium pinnatum grassland. Castle Hills important assemblage of rare and scarce species includes early spider-orchid Ophrys sphegodes and burnt orchid Orchis ustulata. The colony of early spider-orchid is one of the largest in the UK.|
|Cerne and Sydling Downs||Dorset|
|This site consists of a large area of semi-natural dry grassland on the west Dorset chalk. Dry valley slopes with a variety of aspects support extensive examples of CG2 Festuca ovina Avenula pratensis grassland in the south-west of its UK range. A particular feature of this site is the presence of the Succisa pratensis Leucanthemum vulgare sub-community, especially on south- and west-facing slopes. This type of calcareous grassland is almost entirely restricted to parts of Wiltshire and Dorset. On south-west-facing slopes, the nationally scarce dwarf sedge Carex humilis can be abundant in this sub-community.|
|Craven Limestone Complex||North Yorkshire|
|The Craven Limestone Complex in northern England is the second most extensive area of calcareous grassland in the UK, and represents the NVC type CG9 Sesleria albicans Galium sterneri grassland. The site exhibits an exceptional diversity of structural types, ranging from hard-grazed open grasslands, through to tall herb-rich grasslands on ungrazed cliff ledges, such as at Malham Cove, in woodland margins and around 8240 Limestone pavements and screes. It is thus an important example of grassland-scrub transitions.|
|Devil`s Dyke||Cambridgeshire; Suffolk|
|Devils Dyke consists of a mosaic of CG3 Bromus erectus and CG5 Bromus erectus Brachypodium pinnatum calcareous grasslands. It is the only known UK semi-natural dry grassland site for lizard orchid Himantoglossum hircinum.|
|Folkestone to Etchinghill Escarpment||Kent|
|This site consists of extensive CG4 Brachypodium pinnatum and CG5 Bromus erectus Brachypodium pinnatum calcareous grasslands, together with smaller areas of short-turf CG2 Festuca ovina Avenula pratensis grassland. The site contains an important assemblage of rare and scarce species, including early spider-orchid Ophrys sphegodes, late spider-orchid O. fuciflora and burnt orchid Orchis ustulata.|
|Great Orme`s Head/ Pen y Gogarth||Conwy|
|Great Ormes Head in north Wales supports one of the largest stands in the UK of CG1 Festuca ovina Carlina vulgaris grassland. There is also an extensive area of CG2 Festuca ovina Avenula pratensis grassland. This is one of only three selected sites in the UK where this Xerobromion grassland type occurs. The site contains a wide range of structural types, ranging from short turf on south-facing rocky slopes with abundant hoary rock-rose Helianthemum oelandicum, through more closed calcareous grassland communities to tall herb-rich vegetation on scrub margins. Transitions from calcareous grassland to calcareous and acidic heath, cliff, scree and 8240 Limestone pavements are also well-represented.|
|The steep slopes of this site on the chalk of the Chilterns comprise a mosaic of chalk grassland, chalk scrub and broadleaved woodland. The chalk grassland mostly consists of a mosaic of shorter-turf NVC type CG2 Festuca ovinaAvenula pratensis grassland and taller CG3 Bromus erectus grassland. The site supports one of only three UK populations of monkey orchid Orchis simia, a nationally rare Red Data Book species.|
|Isle of Portland to Studland Cliffs||Dorset|
|Semi-natural dry grassland occurs at this site in both inland and coastal situations on both chalk and Jurassic limestone. The site contains extensive species-rich examples of CG4 Brachypodium pinnatum grassland in the southern part of its UK range. Smaller areas of CG2 Festuca ovina Avenula pratensis grassland occur on shallow soils on steeper slopes. Transitions from calcareous grassland to both chalk heath and acid grassland are also present. The site has well-developed terricolous and saxicolous lichen and bryophyte communities associated with open turf, chalk rock and pebbles, and flinty soils.|
|Isle of Wight Downs||Isle of Wight|
|The Isle of Wight Downs complex consists of large areas of semi-natural dry grassland on chalk at the southern extremity of its UK range. It provides extensive examples of CG2 Festuca ovina Avenula pratensis grassland in both inland and coastal situations on a variety of aspects and slope gradients. Locally, the Festuca Avenula grassland grades into CG1 Festuca ovina Carlina vulgaris grassland, particularly on south-facing slopes on the coast. This open, stony grassland contains one of the most important examples of lichen-rich maritime chalk grassland in the UK. Smaller areas of CG3 Bromus erectus grassland occur on the eastern parts of the chalk outcrop. Semi-natural dry grassland is locally replaced by 4030 European dry heaths where superficial deposits overlie the chalk.|
|Lewes Downs||East Sussex|
|This chalk grassland site consists largely of CG2 Festuca ovina Avenula pratensis and CG3 Bromus erectus calcareous grasslands. This site contains an important assemblage of rare and scarce orchids, including early spider-orchid Ophrys sphegodes, burnt orchid Orchis ustulata and musk orchid Herminium monorchis. The colony of burnt orchid is one of the largest in the UK.|
|Lydden and Temple Ewell Downs||Kent|
|This site consists largely of CG4 Brachypodium pinnatum and CG5 Bromus erectus Brachypodium|
|Mendip Limestone Grasslands||North Somerset; Somerset|
|This site comprises coastal and inland sections of the Carboniferous Limestone outcrops of the Mendips. The coastal headland and inland hills support the largest area of CG1 Festuca ovina Carlina vulgaris grassland in England, including two sub-types (CG1a Carex humilis and CG1c Trinia glauca sub-communities) known from no other site in the UK. Areas of short-turf CG2 Festuca ovina Avenula pratensis grassland also occur inland. The site is exceptional in that it supports a number of rare and scarce vascular plants typical of the oceanic southern temperate and Mediterranean elements of the British flora. These include white rock-rose Helianthemum apenninum, Somerset hair-grass Koeleria vallesiana and honewort Trinia glauca. Transitions to limestone heath (4030 European dry heaths) situated on flatter terrain also occur.|
|Mole Gap to Reigate Escarpment||Surrey|
|This large but fragmented site on the North Downs escarpment supports a wide range of calcareous grassland types on steep slopes, including CG2 Festuca ovina Avenula pratensis, CG3 Bromus erectus, CG4 Brachypodium pinnatum, CG5 Brachypodium pinnatum Bromus erectus and CG6 Avenula pubescens grasslands. It exhibits a wide range of structural conditions ranging from short turf through to scrub margins, and is particularly important for rare vascular plants, including orchids (see 6211 Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) (*important orchid sites)). It is also significant in exhibiting transitions to scarce scrub, woodland and dry heath types, notably 5110 Stable xerothermophilous formations with Buxus sempervirens on rock slopes, 91J0 yew Taxus baccata woods, and chalk heath (4030 European dry heaths).|
|Monawilkin is floristically the richest example of blue moor-grass Sesleria grassland in Northern Ireland and represents this variant of semi-natural dry grasslands. The Monawilkin example is rather different from other Sesleria-dominated grasslands in the UK in that it includes species such as eyebright Euphrasia salisburgensis. Although relatively small, the site contains a range of slopes and aspects and an excellent range of transitions to other habitats, including cliffs, screes, flushes, heath and scrub. It also has an important invertebrate fauna.|
|Moor House Upper Teesdale||Cumbria; Durham|
|Extensive stands of CG9 Sesleria albicans Galium sterneri grassland occur at this site in northern England. It is an important variant of this community since it contains a rich assemblage of relict arctic-alpine species, such as spring gentian Gentiana verna and alpine forget-me-not Myosotis alpestris, making Moor House Upper Teesdale one of the most important arctic-alpine refugia in the UK. The grasslands are for the most part heavily grazed but show transitions to a wide range of other vegetation types, including 7130 Blanket bogs, acid grassland, 7230 Alkaline fens, 6520 Mountain hay meadows, 8240 Limestone pavements, cliffs and 8120 calcareous and calcshist screes of the montane to alpine levels.|
|Morecambe Bay Pavements||Cumbria; Lancashire|
|Extensive CG9 Sesleria albicans Galium sterneri grasslands occur at Morecambe Bay Pavements in north-west England. The grassland, which has an overall northern character, is also rich in southern lowland species, so providing important regional variation distinct from Craven Limestone Complex and Moor House Upper Teesdale, also in northern England. There is a wide range of structural variation associated with intensity of grazing and the presence of cliffs, screes, and 8240 Limestone pavements on the margins of the grassland stands. There are important transitions to calcareous scrub and 9180 Tilio-Acerion forests.|
|North Somerset and Mendip Bats||Bath and North East Somerset; North Somerset; Somerset|
|The Cheddar complex and Wookey Hole areas support a wide range of semi-natural habitats including semi-natural dry grasslands. The principal community present is CG2 Festuca ovina Avenula pratensis grassland which occurs on rock ledges and on steep slopes with shallow limestone soil, especially in the dry valleys and gorges and on the south-facing scarp of the Mendips. The site is also important for the large number of rare plants which are associated with Carboniferous limestone habitats. These include dwarf mouse-ear Cerastium pumilum, Cheddar pink Dianthus gratianopolitanus and rock stonecrop Sedum forsterianum, which occur on rocks, screes, cliffs and in open grassland. Transitions to and mosaics with limestone heath, calcareous screes, scrub and 9180 Tilio-Acerion forests are a particular feature of the Cheddar complex part of the site.|
|Parkgate Down is situated on the chalk of the North Downs and consists largely of NVC type CG4 Brachypodium pinnatum grassland. The site contains an outstanding assemblage of orchids including the nationally rare monkey orchid Orchis simia and late spider orchid Ophrys fuciflora together with the nationally scarce musk orchid Herminium monorchis and lady orchid Orchis purpurea.|
|Peak District Dales||Derbyshire; Staffordshire|
|Peak District Dales is one of the most extensive surviving areas in England of CG2 Festuca ovina Avenula pratensis grassland. Grasslands at this site range from hard-grazed short turf through to tall herb-rich vegetation, with transitions through to calcareous scrub and 9180 Tilio-Acerion forests a diversity of structural types unparalleled in the UK. There is also a great physical diversity due to rock outcrops, cliffs, screes and a variety of slope gradients and aspects. In contrast to examples of Festuca Avenula grassland on chalk to the south, these grasslands are less at risk from the threat of invasion by upright brome Bromopsis erecta and tor-grass Brachypodium pinnatum, which are at the edge of their range here and have limited vigour. The relatively cold oceanic nature of the climate means that there is enrichment with northern floristic elements, such as limestone bedstraw Galium sterneri and globeflower Trollius europaeus.|
|This site is situated on the southern edge of the Marlborough Downs on the Wiltshire chalk and consists largely of CG2|
|Queendown Warren consists of CG3 Bromus erectus grassland. It contains an important assemblage of rare and scarce species, including early spider-orchid Ophrys sphegodes, burnt orchid Orchis ustulata and man orchid Aceras anthropophorum.|
|Rex Graham Reserve||Suffolk|
|This is a disused chalk pit with developing dry grassland characterised by false oat-grass Arrhenatherum elatius. The site has been selected as it supports the largest population of military orchid Orchis militaris in the UK, comprising more than 95% of the current total population.|
|Rodborough Common is the most extensive area of semi-natural dry grasslands surviving in the Cotswolds of central southern England, and represents CG5 Bromus erectus Brachypodium pinnatum grassland, which is more or less confined to the Cotswolds. The site contains a wide range of structural types, ranging from short turf through to scrub margins, although short-turf vegetation is mainly confined to areas of shallower soils.|
|Salisbury Plain||Hampshire; Wiltshire|
|Salisbury Plain in central southern England is believed to be the largest surviving semi-natural dry grassland within the EU and is therefore the most important site for this habitat in the UK. It supports extensive examples of CG3 Bromus erectus grassland, which is the most widespread and abundant calcareous grassland found in the UK. It also contains extensive areas of the rare CG7 Festuca ovina Hieracium pilosella Thymus praecox grassland, and one of the largest examples of CG6 Avenula pubescens grassland.|
|South Hams||Devon; Torbay|
|The Devonian limestone headland and cliffs of the Torbay area of south Devon support a large area of the rare CG1 Festuca ovina Carlina vulgaris grassland, including the Scilla autumnalis Euphorbia portlandica sub-community, known from no other site in the UK. The site is exceptional in that it supports a number of rare and scarce vascular plants typical of the oceanic southern temperate and Mediterranean-Atlantic elements of the British flora. These include Portland spurge Euphorbia portlandica, rock stonecrop Sedum forsterianum, autumn squill Scilla autumnalis and small hares-ear Bupleurum baldense. Semi-natural grassland gives way to 4030 European dry heaths on flatter slopes above the cliffs in some areas.|
|St Albans Head to Durlston Head||Dorset|
|This site contains extensive species-rich examples of CG4 Brachypodium pinnatum calcareous grassland. The site holds the largest UK population of early spider-orchid Ophrys sphegodes. This species has declined very dramatically in the UK since the 1950s, in both population size and range.|
|Thrislington is a small site but nonetheless contains the largest of the few surviving stands of CG8 Sesleria albicans Scabiosa columbaria grassland. This form of calcareous grassland is confined to the Magnesian Limestone of County Durham and Tyne and Wear, north-east England. It now covers less than 200 ha and is found mainly as small scattered stands.|
|West Fermanagh Scarplands||Fermanagh|
|West Fermanagh Scarplands contains one of the most extensive areas of blue moor-grass Sesleria albicans grassland in Northern Ireland. This calcareous grassland type is similar to the CG9 Sesleria albicans Galium sterneri grasslands of northern England, but lacks a number of the characteristic species, including Galium sterneri. The community at West Fermanagh Scarplands is dominated by S. caerulea, glaucous sedge Carex flacca and wild thyme Thymus polytrichus, and is particularly notable for its transitions to a wide range of other habitats, including 8240 Limestone pavements and 9180 Tilio-Acerion forests of slopes, screes and ravines.|
|Wye and Crundale Downs||Kent|
|Wye and Crundale Downs consists mostly of NVC types CG4 Brachypodium pinnatum and CG5 Bromus erectusBrachypodium pinnatum grasslands, although small areas of CG2 Festuca ovinaAvenula pratensis grassland also occur. It has an important assemblage of rare, scarce and uncommon orchids, including early spider-orchid Ophrys sphegodes, late spider-orchid O. fuciflora, burnt orchid Orchis ustulata and lady orchid Orchis purpurea. The site contains the largest UK colony of O. fuciflora, representing about 50% of the national population.|
SACs/SCIs/cSACs where this Annex I habitat is a qualifying feature, but not a primary reason for site selection
Many designated sites are on private land: the listing of a site in these pages does not imply any right of public access.