UK Lowland Heathland Habitat Types & Characteristics

 

Dry & humid heath

Heather (aka Ling), the most characteristic plant of dry-humid heathland in the UK © Foxypar4 [CC-BY-SA-2.0 (www.creativecommons.org/licenses/by-sa/2.0)], via Wikimedia CommonsUK dry & humid heath typically occurs on freely-draining, nutrient-poor, acidic soils. The vegetation is characteristically dominated by one or more of the following dwarf-shrubs: heather Calluna vulgaris, bell heather Erica cinerea, cross-leaved heath Erica tetralix, gorse Ulex europaeus, dwarf gorse Ulex minor, western gorse Ulex gallii, bilberry/blaeberry Vaccinium myrtillus, cowberry Vaccinium vitis-idaea, and crowberry Empetrum nigrum ssp. nigrum.

The habitat is generally dependent on grazing and burning to prevent invasion by trees and conversion to woodland. These factors also affect the height and canopy cover, which varies depending on the phase of development and grazing intensity. Following burning and where grazing is more intense, various grass species can be abundant, such as bristle bent Agrostis curtisii, purple moor-grass Molinia caerulea, sheep’s fescue Festuca ovina, and wavy hair-grass Deschampsia flexuosa.

Dry & humid heath varies according to climate and is also influenced by altitude, aspect, soil conditions (especially base-status and drainage), maritime effects and management. There is a general gradation from southerly to northerly kinds, as well as both western (oceanic) and eastern (continental) forms. Humid heath, which occupies soils with slightly impeded drainage, is included in this group. Various lowland dry & humid heath communities, with different geographic ranges, have been identified based on differences in their vegetation communities. These are described below – for further details see NVC field guide to mires and heaths.

 

Eastern continental dry heath

Yellow gorse flowering on dry heath at Westleton Heath, Suffolk © Stephen McKay [CC-BY-SA-2.0 (www.creativecommons.org/licenses/by-sa/2.0)], via Wikimedia CommonsThe semi-continental Calluna vulgaris-Festuca ovina heath of south-east and eastern England is generally species-poor and overwhelmingly dominated by heather. Sometimes it includes a modest diversity of bryophytes and, more especially, lichens. Common gorse is uncommon, except where there has been disturbance. Such heathland often supports an important fauna, including birds such as the European nightjar and Dartford warbler, and reptiles such as the sand lizard and smooth snake.

In south-eastern and central southern parts of England (Kent to Dorset), Calluna vulgaris-Ulex minor heath occurs. This is generally dominated by mixtures of heather, bell heather, dwarf gorse and wavy hair grass. After fire, bell heather often increases because of its prolific seeding. Dwarf gorse normally plays a subsidiary role, forming a patchy understorey to heather. Common gorse is occasional, but may be locally abundant after disturbance.

 

South-western oceanic dry heath

The climate becomes increasingly mild and oceanic towards the south-west of England and in southern Wales. The soils here are therefore slightly damp and different types of dry heath are found.

Bell heather and heather in flower on dry heath at Vereley Hill, New Forest © Gillian Moy [CC-BY-SA-2.0 (www.creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

From the New Forest and west to Dorset, Ulex minor-Agrostis curtisii heath occurs. Heather frequently dominates this vegetation, especially where there has been no recent burning. Dwarf gorse is a frequent associate, but very variable in abundance. Unlike on more easterly heaths, both bell heather and cross-leaved heath occur and they can be prominent – bell heather especially after burning and cross-leaved heath on more strongly gleyed soils. Bristle bent and purple moor-grass are characteristic grasses – after burning they can also become prominent. Various other species can be found occasionally, for example bracken Pteridium aquilinum, tormentil Potentilla erecta, heath milkwort Polygala serpyllifolia, pill sedge Carex pilulifera, and the curious parasitic plant, dodder Cuscuta epithymum.

Across south-west England and into southern Wales, Ulex gallii-Agrostis curtisii heath occurs. This is very similar to Ulex minor-Agrostis curtisii heath, the major difference being the replacement of one dwarf gorse species by another, i.e. dwarf gorse Ulex minor by the western gorse Ulex gallii, the western limits of which in east Dorset forms the boundary between these two heath types.

 

Central warm oceanic heath

Heather and western gorse forming oceanic heath near South Stack, Anglesey © John Rostron [CC-BY-SA-2.0 (www.creativecommons.org/licenses/by-sa/2.0)], via Wikimedia CommonsAt low to moderate altitudes in warm oceanic parts of southern Britain (from south-west England, across Wales and the northern Midlands and round into Norfolk and Suffolk), the typical form of heathland is Calluna vulgaris-Ulex gallii heath. This vegetation type is a characteristically diverse with abundant heather, western gorse and bell heather, and no cross-leaved heath, purple moor-grass or bristle bent. Common gorse may be abundant on disturbed ground, and both bracken and bramble may be present.

 

Upland transitional (sub-montane) cool oceanic heath

In the cooler oceanic climate of western and northern Britain, where there is a transition from lowland-upland areas, western gorse becomes scarce and Calluna vulgaris-Erica cinerea heath becomes the common heath type. This is typically dominated by heather, although this depends on the intensity and timing of burning and grazing. Bell heather is frequent, especially on more southerly-facing slopes, and becomes dominant in the hyper-oceanic fringes of the north-west. However, bilberry/blaeberry, cowberry and crowberry remain relatively scarce.

In marked contrast, in the heather-dominated Calluna vulgaris-Vaccinium myrtillus heath, bilberry/blaeberry is commonly encountered and grows vigorously when out of reach of grazing animals, and both cowberry and crowberry can be locally abundant, along with bell heather. This heath type accounts for most of the heathland from less oceanic, northern and western, sub-montane areas, where burning is commonly practised, including many of the moors managed for grouse shooting.Bilberry, a common heathland plant in less oceanic, northern and western, sub-montane areas © Pauline Eccles [CC-BY-SA-2.0 (www.creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

In even less oceanic areas, at low to moderate elevations from the Midlands, across northern England and in parts of eastern Scotland, extensive stands of Calluna vulgaris-Deschampsia flexuosa heath are often encountered. This heath is characteristically species-poor and overwhelmingly dominated by heather, often growing with a fairly low and open canopy with some wavy hair-grass. No other dwarf-shrubs are consistently frequent, although some can be quite common and locally abundant; bilberry/blaeberry being the most important, particularly at higher altitudes, with cowberry and crowberry being more localised.

 

Coastal dry heath

Dry heath also occurs on cliffs and slopes around the UK located near to the sea. This mainly forms Calluna vulgaris-Scilla verna heath, which is characteristically low-growing and usually contains the attractive spring squill Scilla verna. Although dwarf-shrubs are a consistent feature of this vegetation, they are not always obvious and rarely continuous; even where more extensive, they are commonly penetrated by herbs such as bird's-foot trefoil Lotus corniculatus and wild thyme Thymus praecox. Heather is the most frequent dwarf-shrub and is often dominant, though on dry soils it is normally accompanied by bell heather. On wetter soils, cross-leaved heath and/or crowberry are the usual associates. Western gorse is found occasionally. In the far north, on Orkney and Shetland, and in north-west Wales, there is an unusual lichen-rich, waved form of this heath typeCoastal heath at Gwennap Head, with heather, bell heather and western gorse © Jim Champion [CC-BY-SA-2.0 (www.creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons.

In the warm, oceanic, coastal climate of The Lizard Peninsular in Cornwall, Erica vagans-Ulex europaeus heath occurs. This is a nationally rare and distinctive type of dry heath, in which Cornish heath Erica vagans and common gorse are the main co-dominants. Both western gorse and bell heather occur commonly and in places are abundant. Heather is, however, notably infrequent. The height and cover of dwarf-shrubs is variable, reflecting differences in grazing, burning and soil conditions – in exposed situations the vegetation can be very short. Various grasses and herbs are widespread, including betony Stachys officinalis, brown bent Agrostis vinealis, common dog-violet Viola riviniana, common milkwort Polygala vulgaris, glaucous sedge Carex flacca, and meadowsweet Filipendula ulmaria. This reflects the peculiar association of this habitat with well-drained, moderately base-rich soils derived from serpentine rock.

Coastal dry heath also occurs in certain situations on acidic sand dunes and sandy shingle – see UK Coastal Habitats Correspondence Table. This can take the form of Calluna vulgaris-Carex arenaria heath, in which sand sedge Carex arenaria is a constant and defining feature, and heather, bell heather, and (in north and east Scotland) crowberry are the main dwarf-shrubs. This is, by far, the key dune heath community in Scotland. In other places, the vegetation of coastal dunes takes on the characteristics of Calluna vulgaris-Festuca ovina heath (albeit distinguished again by the presence of sand sedge) or of Calluna vulgaris-Erica cinerea heath.

 

Wet heath

UK wet heath is associated with acidic, nutrient-poor, shallow peat or sandy soils with impeded drainage. The vegetation is typically dominated by a range of dwarf-shrubs and other species including cross-leaved heath, heather, bell heather, bilberry/blaeberry, bog myrtle Myrica gale, purple moor-grass, deer-grass Scirpus cespitosus, and various Sphagnum bog-mosses. Wet heath is an important habitat for a range of vascular plant and bryophytes species with an oceanic or Atlantic distribution in Europe.

Various lowland wet heath communities, with different geographic ranges, have been identified based on differences in their vegetation communities. These are described below. For further details see NVC field guide to mires and heaths.

 

Upland transitional wet heath

The typical form of this habitat where rainfall is moderate to high in the north and west of the UK is Scirpus cespitosus-Erica tetralix wet heath. The vegetation associated with this has few constants and shows wide variation in the pattern of dominance. Most stands comprise mixtures of purple moor-grass, deer-grass, cross-leaved heath and/or heather are usually characteristic, though one or more may be lacking entirely. Bell heather, bilberry/blaeberry, bog myrtle, Sphagnum bog-mosses, round-leaved sundew Drosera rotundifolia, bog asphodel Narthecium ossifragum, common cottongrass Eriophorum angustifolium, mat grass Nardus stricta and heath rush Juncus squarrosus are important in particular sub-communities. In the north, there may be a high cover of Cladonia lichens, whilst in the far north-west of Scotland, woolly fringe-moss Racomitrium lanuginosum and an abundance of Atlantic bryophytes is characteristic.

 

Drier forms of wet heath

Where the conditions are drier in the north and west, but also in the south and east, Erica tetralix-Sphagnum compactum wet heath is characteristic. This is usually dominated by mixtures of cross-leaved heath, heather and purple moor-grass in variable amounts, being influenced by differences in the water regime, soil nutrient status, grazing and burning. The bog-moss Sphagnum compactum is typically abundant. Bell heather and western or dwarf gorse may be abundant in transitions to drier heath in southern England. In the south, species with a mainly southern distribution, such as marsh gentian Gentiana pneumonanthe, brown beak-sedge Rhynchospora fusca and meadow thistle Cirsium dissectum, enrich the vegetation. On Orkney and at high altitude in the Scottish Highlands, Cladonia lichens are abundant.

 

Other wet heath types

A further very local wet heath type is Schoenus nigricans-Narthecium ossifragum mire. This is mainly associated with transitions from heath to valley bog at a small number of lowland sites from south-west England to East Anglia. Black bog-rush Schoenus nigricans is usually dominant, purple moor-grass abundant, and bog asphodel and bog pimpernel Anagallis tenella frequent. Other characteristic plants include round-leaved sundew, bell heather, and bog myrtle.

A distinctive and nationally rare form of this habitat grows on the The Lizard Peninsular in Cornwall, i.e. Erica vagans-Schoenus nigricans wet heath. The Cornish heath Erica vagans makes a constant and prominent contribution to the vegetation, along with black bog-rush, purple moor-grass and cross-leaved heath. Western gorse occurs with some frequency and may be co-dominant, but heather is only occasional and bell heather is scarce. The spiny petty whin Genista anglica can occur frequently and is preferential to this community.