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Special Areas of Conservation

4010 Northern Atlantic wet heaths with Erica tetralix

Temperate heath and scrub

Description and ecological characteristics

Wet heath usually occurs on acidic, nutrient-poor substrates, such as shallow peats or sandy soils with impeded drainage. The vegetation is typically dominated by mixtures of cross-leaved heath Erica tetralix, heather Calluna vulgaris, grasses, sedges and Sphagnum bog-mosses.

In the UK this vegetation corresponds to the following NVC types:

  • H5  Erica vagans – Schoenus nigricans heath
  • M14  Schoenus nigricans – Narthecium ossifragum mire
  • M15  Scirpus cespitosus – Erica tetralix wet heath
  • M16  Erica tetralix – Sphagnum compactum wet heath
M15 Scirpus – Erica wet heath is found in areas with a moderate to high rainfall, and is the typical form of wet heath in the north and west of the UK. E. tetralix and Calluna are typically accompanied by abundant deergrass Trichophorum cespitosum and purple moor-grass Molinia caerulea. In the far north-west of Scotland, bell heather Erica cinerea and woolly fringe-moss Racomitrium lanuginosum are also characteristic, along with an abundance of Atlantic bryophytes. In the north, there may be a high cover of Cladonia lichens. At high altitude northern and montane species are represented. Where there is movement of mildly base-rich water through the peat, sedges Carex spp. and a wide range of species favoured by flushing occur. The latter includes distinctive variants that are often characterised by abundant bog-myrtle Myrica gale, or black bog-rush Schoenus nigricans.

M16 Erica – Sphagnum wet heath is characteristic of drier climates in the south and east, and is usually dominated by mixtures of E. tetralix, Calluna and Molinia. The bog-moss Sphagnum compactum is typically abundant, while on Orkney and at high altitude in the eastern Scottish Highlands, Cladonia lichens are abundant. In the south, species with a mainly southern distribution in Britain, such as marsh gentian Gentiana pneumonanthe, brown beak-sedge Rhynchospora fusca and meadow thistle Cirsium dissectum, enrich wet heaths. At high altitude in northern Scotland forms of the community rich in northern and montane species occur and often also have an abundance of Cladonia lichens.

On the Lizard in Cornwall, Cornish heath Erica vagans growing with S. nigricans, E. tetralix and Molinia forms a distinctive and unique form of wet heath (H5 Erica – Schoenus heath), found nowhere else in Europe. A further very local wet heath type is M14 Schoenus – Narthecium mire, which is mainly associated with transitions from heath to valley bog at a small number of lowland sites in southern Britain. Forms of Schoenus – Narthecium mire with Cladium are referable to Annex I type 7210 Calcareous fens with Cladium mariscus and species of the Caricion davallianae.

The full range of variation within wet heath in the UK also includes types rich in lichens, Racomitrium lanuginosum or S. nigricans found in the Hebrides and Northern Isles of Scotland, which are not adequately described by the NVC.

Wet heaths occur in several types of ecological gradient. In the drier areas of the south and east, wet heaths are local and often restricted to the transition zone between 4030 European dry heaths and constantly wet valley mires. In the uplands they occur most frequently in gradients between dry heath or other dry, acid habitats and 7130 Blanket bogs. At high altitude in the Scottish Highlands wet heaths occur in mosaics with 4060 Alpine and Boreal heaths; in these situations lichens and northern or montane species may be well-represented. Flushed wet heaths are especially frequent in areas of high rainfall, and occur as topogenous fens, usually in channels within heath or grassland vegetation.

Wet heath is an important habitat for a range of vascular plant and bryophyte species of an oceanic or Atlantic distribution in Europe, several of which have an important part of their EU and world distribution in the UK.

Distribution of SACs/SCIs/cSACs with habitat 4010 Northern Atlantic wet heaths with Erica tetralix. Click image for enlarged map.

European status and distribution

Northern Atlantic wet heaths with Erica tetralix are restricted to the Atlantic fringe of Europe between Norway and Normandy. A high proportion of the EU resource occurs in the UK.

UK status and distribution

Northern Atlantic wet heaths with Erica tetralix occur throughout the UK but are highly localised in parts of southern and central England. Wet heaths become increasingly extensive in the cool and wet north and west, especially in the Scottish Highlands. However, the area covered by wet heath is significantly smaller than that covered by 7130 Blanket bogs or dry heath.

Click here view UK distribution of this species

Site accounts

  • Ashdown Forest Surrey, East and West Sussex
    Ashdown Forest contains one of the largest single continuous blocks of lowland heath in south-east England, with both 4030 European dry heaths and, in a larger proportion, wet heath. The M16 Erica tetralix – Sphagnum compactum wet heath element provides suitable conditions for several species of bog-mosses Sphagnum spp., bog asphodel Narthecium ossifragum, deergrass Trichophorum cespitosum, common cotton-grass Eriophorum angustifolium, marsh gentian Gentiana pneumonanthe and marsh clubmoss Lycopodiella inundata. The site supports important assemblages of beetles, dragonflies, damselflies and butterflies, including the nationally rare silver-studded blue Plebejus argus, and birds of European importance, such as European nightjar Caprimulgus europaeus, Dartford warbler Sylvia undata and Eurasian hobby Falco subbuteo.
  • Breney Common and Goss and Tregoss Moors Cornwall and Isles of Scilly
    This lowland site exhibits mosaics of various habitats, including 4030 European dry heaths, wet heaths, acid grassland, bog, swamp, fen and open water communities. The soil-structure of these sites reflects past mining operations, which caused poor drainage. The resulting extensive wet communities include the localised M14 Schoenus nigricans – Narthecium ossifragum mire, closely associated with M25 Molinia caerulea – Potentilla erecta mire. There are several species of bog-mosses Sphagnum spp., bog asphodel Narthecium ossifragum, orchids and some nationally scarce plants, such as yellow centaury Cicendia filiformis, marsh clubmoss Lycopodiella inundata and pillwort Pilularia globulifera. The habitat supports rich assemblages of butterflies (including the Annex II species 1065 marsh fritillary Euphydryas aurinia), moths, dragonflies and damselflies, and also a population of European nightjar Caprimulgus europaeus.
  • Cairngorms Highlands and Islands, North Eastern Scotland
    The Cairngorms is representative of Northern Atlantic wet heaths with Erica tetralix in north-east Scotland and has the largest extent of this habitat in this part of the UK. M16 Erica tetralix – Sphagnum compactum wet heath is the most extensive community. The site is notable for the occurrence, at high elevation, of this eastern vegetation type, more typically associated with southern lowland heaths. The more oceanic M15 Scirpus cespitosus – Erica tetralix wet heath is also present, occupying the more strongly-flushed soils. It is the presence of undisturbed lichen-rich wet heath occupying wet hollows within high-altitude, windswept 4060 Alpine and Boreal heaths that is of particular importance. Wet heath is also developed in hollows within the upper parts of 91C0 Caledonian forest, within blanket mire and dry heath, giving a variety of ecological transitions. The rare montane ground-beetle Amara alpina is associated with wet heath in the Cairngorms, feeding on seed-heads of deergrass Trichophorum cespitosum.
  • Dartmoor Devon
    Dartmoor is representative of upland wet heath in south-west England. M15 Scirpus cespitosus – Erica tetralix wet heath predominates and together with other mire communities and small areas of drier heathland, forms a distinctive mosaic of vegetation types not fully represented elsewhere. Smaller amounts of M16 Erica tetralix – Sphagnum compactum wet heath occur. Additionally, there are transitions to areas of M21 Narthecium ossifragum – Sphagnum papillosum valley mire.
  • Dorset Heaths Dorset and Somerset
    This is a complex site which includes 37 SSSIs, most of which include fine transitions between 4030 European dry heaths and wet lowland heathland and mires, as well as other habitats such as woodland, grassland, pools, saltmarsh and reedswamp. The common characteristics of the M16 Erica tetralix – Sphagnum compactum wet heaths are the dominance of cross-leaved heath Erica tetralix, heather Calluna vulgaris and purple moor-grass Molinia caerulea, and the presence of a diverse group of rare species. These include Dorset heath Erica ciliaris (which readily hybridises with E. tetralix), white beak-sedge Rhynchospora alba, brown beak-sedge R. fusca, marsh gentian Gentiana pneumonanthe, great, round- and oblong-leaved sundews Drosera anglica, D. rotundifolia and D. intermedia, and marsh clubmoss Lycopodiella inundata. Typical mosses of the wet heath include Sphagnum compactum, S. pulchrum and S. tenellum. These sites are a stronghold for invertebrates, particularly dragonflies, damselflies, butterflies and spiders, including the Annex II species 1044 Southern damselfly Coenagrion mercuriale. Within the UK, some of these invertebrates are restricted to the Dorset heaths.
  • Dorset Heaths (Purbeck and Wareham) and Studland Dunes Dorset and Somerset
    The two Dorset Heaths SACs, together with the New Forest (also in southern England), contain a large proportion of the total UK resource of lowland northern Atlantic wet heaths. The habitat is of the M16 Erica tetralix – Sphagnum compactum wet heath type and occurs as well-developed transitions between dry heath and valley bog. This habitat type is important for rare plants, such as marsh gentian Gentiana pneumonanthe, brown beak-sedge Rhynchospora fusca and great sundew Drosera anglica. The wet heaths and mires are also important for scarce Odonata, such as small red damselfly Ceriagrion tenellum and the Annex II species 1044 Southern damselfly Coenagrion mercuriale. The sites are an important transitional area between the more oceanic heathlands of the south-west peninsula and the semi-continental heathlands of eastern England.
  • East Devon Pebblebed Heaths Devon
    This is the largest block of lowland heathland in Devon and is associated with various other mire communities. The wet element occupies the lower-lying areas and includes good examples of M16 Erica tetralix – Sphagnum compactum wet heath. Among the 21 breeding dragonfly species is the Annex II species 1044 Southern damselfly Coenagrion mercuriale. There is also an important assemblage of birds, including European nightjar Caprimulgus europaeus, Eurasian hobby Falco subbuteo and Dartford warbler Sylvia undata.
  • Eastern Mournes Northern Ireland
    The Eastern Mournes is one of the largest and most natural areas of heathland in Northern Ireland. Although much of the vegetation consists of 4030 European dry heaths, the site also represents one of the largest areas of Northern Atlantic wet heaths with Erica tetralix in Northern Ireland. M15 Scirpus cespitosus – Erica tetralix wet heath predominates, and this community, together with the dry heaths and other mire communities, forms part of a well-defined altitudinal sequence between 70 m and 800 m. Transitions between the wet and dry heaths occur as a consequence of altitude, aspect and slope, with the wet heaths tending to be best developed on lower north-facing slopes. The community is characterised by cross-leaved heath Erica tetralix, purple moor-grass Molinia caerulea, deergrass Trichophorum cespitosum, carnation sedge Carex panicea and Sphagnum bog-mosses. Unusual elements in the flora include a high proportion of bell heather Erica cinerea, which is generally associated with more freely-draining soils, and black bog-rush Schoenus nigricans, which is locally frequent in areas of more pronounced water-movement. The wet heaths are also notable for the abundance of the rare northern Atlantic moss Campylopus setifolius.
  • Exmoor Heaths Devon, Dorset and Somerset
    Exmoor is representative of upland wet heath in south-west England. M15 Scirpus cespitosus – Erica tetralix wet heath predominates on gently-sloping and level ground. It is extremely variable in nature and has in places been modified by management, particularly burning. Typically, heather Calluna vulgaris dominates, with scattered plants of purple moor-grass Molinia caerulea, cross-leaved heath Erica tetralix, bilberry Vaccinium myrtillus and deergrass Trichophorum cespitosum. In other areas Molinia and Calluna are more-or-less co-dominant, with the former forming tussocks. There are transitions to H12 Calluna vulgaris – Vaccinium myrtillus heath on well-drained, steeper slopes and to M17 Scirpus cespitosus – Eriophorum vaginatum blanket mire on deeper peat, where the northern species crowberry Empetrum nigrum occurs.
  • Fannich Hills Highlands and Islands
    In common with other selected sites in the north west Highland region, the wet heaths at Fannich Hills have some notable floristic features, for example the presence of suites of Atlantic bryophytes including Pleurozia purpurea, Campylopus atrovirens and Breutelia chrysocoma. There is a large area of oceanic, rocky wet heath on shallow peat, with much woolly fringe-moss Racomitrium lanuginosum, Cladonia lichens and bell heather Erica cinerea. Some parts are boreal in character, supporting abundant lichens. An especially unusual feature of these heaths is the presence of dwarf birch Betula nana. The range of habitat sub-types present is similar to those found on other nearby sites, but they are more extensively developed at Fannich Hills.
  • Foinaven Highlands and Islands
    Foinaven is representative of the range of northern Atlantic wet heaths in the more highly oceanic and cool parts of the north-west Scottish Highlands. This site has one of the largest extents of M15 Scirpus cespitosus – Erica tetralix wet heath within the SAC series. It includes the best example in the north-west Highlands of Cladonia-rich wet heath with an abundance of woolly fringe-moss Racomitrium lanuginosum and the large Atlantic liverwort Pleurozia purpurea (comparable with the same sub-type on North Harris but not as rich in Atlantic bryophytes). In the harsh climate high on quartzite plateaux there is an outstanding montane flora, including mountain everlasting Antennaria dioica, arctic bearberry Arctostaphylos alpinus, bearberry Arctostaphylos uva-ursi, alpine clubmoss Diphasiastrum alpinum, common juniper Juniperus communis ssp. nana, trailing azalea Loiseleuria procumbens and the lichen Cetraria islandica. More typical wet heath rich in deergrass Trichophorum cespitosum or purple moor-grass Molinia caerulea occurs on the lower ground, where the flora includes the bog-moss Sphagnum capillifolium, lousewort Pedicularis sylvatica and heath milkwort Polygala serpyllifolia. There is also good representation of flushed wet heath with carnation sedge Carex panicea, bog asphodel Narthecium ossifragum, common cottongrass Eriophorum angustifolium, black bog-rush Schoenus nigricans and Sphagnum denticulatum.
  • Glen Tanar North Eastern Scotland
    Glen Tanar supports, adjacent to and above the native 91C0 Caledonian forest, extensive stands of dry and wet heath, and smaller areas of 7130 blanket bog. The wet heath comprises representative examples of both of the main northern Atlantic wet heath communities, i.e. M15 Scirpus cespitosus – Erica tetralix wet heath and, in particular, M16 Erica tetralix – Sphagnum compactum wet heath.
  • Gower Commons/ Tiroedd Comin Gŵyr East Wales
    This south Wales site supports several extensive tracts of lowland vegetation of NVC type M15 Scirpus cespitosus – Erica tetralix wet heath. There are well-developed transitions to stands of humid and dry heath and to various forms of soligenous and topogenous mire, as well as to woodland, scrub, and bracken Pteridium aquilinum. The site includes strong populations of a number of western species, including whorled caraway Carum verticillatum and the Annex II butterfly 1065 Marsh fritillary Euphydryas aurinia.
  • Hoy Highlands and Islands
    The northern form of northern Atlantic wet heaths, characterised by an abundance of lichens, is very local in the UK but is extensively developed on Hoy. Both M15 Scirpus cespitosus – Erica tetralix wet heath and M16 Erica tetralix – Sphagnum compactum wet heath are found here and are relatively undisturbed. This lack of disturbance may have contributed to the luxuriance of the lichen cover. A range of transitions to 4060 Alpine and Boreal heaths, 7130 Blanket bogs and flush mire are also found on this site.
  • Inverpolly Highlands and Islands
    With Foinaven, this site provides an outstanding example of Northern Atlantic wet heaths with Erica tetralix in the north-west Scottish Highlands. The heaths are extensive and include a range of sub-types of M15 Scirpus cespitosus – Erica tetralix wet heath characteristic of the north-west Highlands. The most extensive type is typical wet heath with an abundance of deergrass Trichophorum cespitosum or purple moor-grass Molinia caerulea. There is also an especially large extent of flushed wet heath with carnation sedge Carex panicea and bog myrtle Myrica gale, and more locally, black bog-rush Schoenus nigricans. An oceanic form of Cladonia-rich wet heath with abundant woolly fringe-moss Racomitrium lanuginosum is moderately extensive at higher levels on rockier ground. The wet heath grades into typical western 7130 Blanket bogs, also a qualifying habitat at this site.
  • Lake District High Fells Cumbria
    Lake District High Fells is representative of wet heath in the uplands of north-west England. The habitat generally occurs throughout the complex in a mosaic of other habitats such as 7130 Blanket bogs and 4030 European dry heaths. Armboth Fells, Shap Fells, Skiddaw Group and the Buttermere Fells have good examples of M15 Scirpus cespitosus – Erica tetralix wet heath characteristic of the north and west. Shap Fells also has an area of M16 Erica tetralix – Sphagnum compactum wet heath. Heather Calluna vulgaris is dominant, with cross-leaved heath Erica tetralix and Sphagnum species. Purple moor-grass Molinia caerulea can be locally abundant.
  • Merrick Kells South Western Scotland
    Merrick Kells in south-west Scotland is representative of the typical western upland forms of M15 Scirpus cespitosus – Erica tetralix wet heath, including forms rich in deergrass Trichophorum cespitosum and those with purple moor-grass Molinia caerulea. This is the most extensive representation of wet heath in the UK on an upland site south of the Scottish Highlands.
  • North Harris Highlands and Islands
    North Harris represents Northern Atlantic wet heaths with Erica tetralix in the Outer Hebrides, and provides examples of the most extreme oceanic forms of wet heath in the UK and possibly Europe. The habitat is closest in its floristics to M15 Scirpus cespitosus – Erica tetralix wet heath. In the most extensive development of this habitat, woolly fringe-moss Racomitrium lanuginosum is characteristically abundant, along with bell heather Erica cinerea (usually characteristic of dry heath) and Atlantic mosses and liverworts. The latter are more prominent here than on any other wet heath site. A highly acidic flushed form of wet heath is frequent, with an abundance of the rare Atlantic moss Campylopus shawii. Wet heath is one of the main elements in the vegetation cover, and is proportionally more extensive than anywhere else in the UK. Wet heath on Harris is not confined to wet hollows or gentle slopes but runs up moderately steep slopes to around 30° or more. There are also transitions to 4030 European dry heath, 7130 Blanket bogs and grassland.
  • North York Moors North Yorkshire, Tees Valley and Durham
    This site in north-east Yorkshire within the North York Moors National Park contains the largest continuous tract of upland heather moorland in England. M16 Erica tetralix – Sphagnum compactum wet heath is the second most extensive vegetation type on the site and is predominantly found on the eastern and northern moors where the soil is less free-draining. Purple moor-grass Molinia caerulea and heath rush Juncus squarrosus are also common within this community. In the wettest stands bog-mosses, including Sphagnum tenellum, occur, and the nationally scarce creeping forget-me-not Myosotis stolonifera can be found in acid moorland streams and shallow pools.
  • Roydon Common and Dersingham Bog East Anglia
    Roydon Common and Dersingham Bog represent the largest and best examples of M16 Erica tetralix – Sphagnum compactum wet heath in East Anglia. This vegetation community is part of a lowland mixed valley mire, a complex series of plant communities grading from wet acid heath through valley mire to calcareous fen. This gradation is of outstanding interest. The mire is extremely diverse and supports many rare plants, birds and insects, including the dragonfly Sympetrum scoticum, a northern species with a very local distribution in south-east England. Birds protected at European level occurring in the heathland at this site include European nightjar Caprimulgus europaeus, hen harrier Circus cyaneus and merlin Falco columbarius.
  • Rum Highlands and Islands
    Rum, in the Inner Hebrides, has an extensive development of the black bog-rush Schoenus nigricans-rich form of northern Atlantic wet heaths that is restricted to western Scotland. It is extensive on slopes which are underlain by ultra-basic rocks, and shows the development of Schoenus in response to mild base-rich flushing. The Schoenus-rich form has affinities to the strongly-flushed Carex panicea sub-community of M15 Scirpus cespitosus – Erica tetralix wet heath, and shows some similarities to the Schoenus-rich heaths of the Lizard district, which are also on ultra-basic rocks. Other more typical western forms of wet heath with abundant deergrass Trichophorum cespitosum and purple moor-grass Molinia caerulea are also represented.
  • Skipwith Common North Yorkshire
    The northern Atlantic wet heath at Skipwith Common is the most extensive of its type in the north of England. The M16 Erica tetralix – Sphagnum compactum wet heath is dominated by cross-leaved heath Erica tetralix and purple moor-grass Molinia caerulea. There is a small population of marsh gentian Gentiana pneumonanthe. The wet heath is part of transitions from open water, fen, reed and swap to 4030 European dry heaths and other habitats. The site has great ornithological and entomological importance.
  • Strathglass Complex Highlands and Islands
    Strathglass Complex has extensive northern Atlantic wet heaths of M15 Scirpus cespitosus – Erica tetralix wet heath with a wide range of sub-types representative of the western Scottish Highlands. The wet heaths are intermediate between examples on the hyper-oceanic western seaboard and Western Isles, those on the more continental Cairngorms, and those in the Northern Isles. Western Molinia-rich and flushed Myrica-Molinia sub-types are extensive and are associated with western 7130 Blanket bogs, 4030 European dry heaths and 91C0 Caledonian forest on the lower slopes. The site is especially notable for the extensive development of a northern form of wet heath at high altitude. These have abundant Cladonia lichens, woolly fringe-moss Racomitrium lanuginosum, alpine bearberry Arctostaphylos alpina, dwarf birch Betula nana and crowberry Empetrum nigrum, and are comparable only with wet heaths on the Cairngorms, north Hoy and Foinaven.
  • Strensall Common North Yorkshire
    Strensall Common, together with Skipwith Common, is an example of acidic lowland heath in northern England. The wet element is well-represented by M16 Erica tetralix – Sphagnum compactum wet heath, although its extent has been reduced by drainage. It is a noted locality for marsh gentian Gentiana pneumonanthe, narrow buckler-fern Dryopteris carthusiana and long-leaved sundew Drosera intermedia.
  • The Lizard Cornwall and Isles of Scilly
    The Lizard peninsula in the extreme south-west of England has a unique type of wet heath, NVC type H5 Erica vagans – Schoenus nigricans heath. This wet heath occurs extensively on poorly-drained soils derived from ultra-basic serpentine and gabbro. It contains unusual mixtures of species characteristic of acid soils growing with species typical of base-rich soils.
  • The New Forest Gloucestershire, Wiltshire and Bristol/Bath area, Hampshire and Isle of Wight
    The New Forest contains the most extensive stands of lowland northern Atlantic wet heaths in southern England, mainly of the M16 Erica tetralix – Sphagnum compactum type. M14 Schoenus nigricans – Narthecium ossifragum mire is also found on this site. The wet heaths are important for rare plants, such as marsh gentian Gentiana pneumonanthe and marsh clubmoss Lycopodiella inundata, and a number of dragonfly species, including the scarce blue-tailed damselfly Ischnura pumilio and small red damselfly Ceriagrion tenellum. There is a wide range of transitions between wet heath and other habitats, including dry heath, various woodland types, Molinia grasslands, fen, and acid grassland. Wet heaths enriched by bog myrtle Myrica gale are a prominent feature of many areas of the Forest. Unlike much lowland heath, the New Forest heaths continue to be extensively grazed by cattle and horses, favouring species with low competitive ability.
  • Thursley, Ash, Pirbright and Chobham Surrey, East and West Sussex
    This site represents lowland northern Atlantic wet heaths in south-east England. The wet heath at Thursley is NVC type M16 Erica tetralix – Sphagnum compactum and contains several rare plants, including great sundew Drosera anglica, bog hair-grass Deschampsia setacea, bog orchid Hammarbya paludosa and brown beak-sedge Rhynchospora fusca. There are transitions to valley bog and dry heath. Thursley Common is an important site for invertebrates, including the nationally rare white-faced darter Leuccorhinia dubia.

SACs 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.

Please note that the map shows sites where the presence of a feature is classed as ‘grade d’, but these sites are not listed. This is because ‘grade d’ indicates a non-significant presence.