Upland Heathland

Upland heathland normally occurs above the limit of agricultural enclosure but below the limit of the permanent tree-line, i.e. between 250–400 m and 600–750 m altitude. However, in northern Scotland, it descends to near sea-level. It occurs on substrates that range from thin, stony, well-drained mineral soils to shallow peats <0.5 m, and is characterised by a cover of dwarf shrubs of at least 25%.

 

The main shrubs dwarf shrub species encountered are: heather Calluna vulgaris, bearberry Arctostaphylos uva-ursi, bell heather Erica cinerea, bilberry/blaeberry Vaccinium myrtillus, cowberry Vaccinium vitis-idaea, cross-leaved heath Erica tetralix, crowberry Empetrum nigrum, dwarf gorse Ulex minor, gorse Ulex europaeus, and western gorse Ulex gallii.  Some upland heath supports abundant juniper Juniperus communis.

 

Upland heathland vegetation is sub-divided into two broad types:

 

Wet upland heathland

Wet upland heathland usually occurs on soils with impeded drainage that are acidic and nutrient-poor, such as shallow peats or sandy soils. It is found widely across the uplands of the UK, but is particularly abundant in the western Scottish Highlands and Islands.

Cross-leaved heath (Erica tetralix). @ Ian Strachan

The typical form of this habitat is Scirpus cespitosus-Erica tetralix wet heath. This occurs where rainfall is moderate to high in the north and west of the UK. The vegetation shows wide variation in the pattern of dominance. Most stands comprise mixtures of purple moor-grass Molina caerulea, deer-grass Trichophorum cespitosum, cross-leaved heath Erica tetralix, and/or heather Calluna vulgaris, though one or more may be lacking entirely. Bell heather Erica cinerea, bilberry/blaeberry Vaccinium myrtillus, bog myrtle Myrica gale, Sphagnum bog-mosses, round-leaved sundew Drosera rotundifolia, bog asphodel Narthecium ossifragum, common cotton-grass 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.

Where conditions are drier, Erica tetralix-Sphagnum compactum wet heath is characteristic. This is usually dominated by mixtures of cross-leaved heath Erica tetralix, heather Calluna vulgaris, and purple moor-grass Molina caerulea. The bog-moss Sphagnum compactum is typically abundant. At high altitude in the Scottish Highlands, Cladonia lichens are abundant.

Similar ‘wet heath’ vegetation occurs on blanket bog.

 

Heather. @ Ian StrachanDry & humid upland heathland

Dry & humid upland heathland is typically associated with free-draining, low nutrient, acidic to circum-neutral soils. Nearly all of it originates from woodland, which has been heavily grazed and burnt. Most is still grazed by livestock and deer, and many sites are used for grouse shooting. Although it also occurs widely across the uplands of the UK, it tends to have a less oceanic, more easterly distribution compared to wet upland heath.

A number of dry & humid upland heath vegetation types have been recognised – summary details of which are given in the table below. Some of these types also occur in Mountain Heaths and Lowland Heathland.

 

NVC type

Main locations

Major plants

H4 Ulex gallii-Agrostis curtisii heath

SW England

Heather Calluna vulgaris, bristle bent Agrostis curtisii, western gorse Ulex gallii, purple moor-grass Molina caerulea, bell heather Erica cinerea, cross-leaved heath Erica tetralix, tormentil Potentilla erecta

H8 Calluna vulgaris-Ulex gallii heath

SW England, W Wales, S Pennines

Heather Calluna vulgaris, western gorse Ulex gallii, bell heather Erica cinerea

H9 Calluna vulgaris-Deschampsia flexuosa heath

S Pennines & North York Moors

Heather Calluna vulgaris, wavy hair-grass Deschampsia flexuosa

H10 Calluna vulgaris-Erica cinerea heath

Widespread, but especially SW Scotland

Heather Calluna vulgaris, bell heather Erica cinerea, tormentil Potentilla erecta

H12 Calluna vulgaris-Vaccinium myrtillus heath

Widespread, but especially central & E Scotland

Heather Calluna vulgaris, bilberry/blaeberry Vaccinium myrtillus, various mosses, cowberry Vaccinium vitis-idaea, crowberry Empetrum nigrum, bell heather Erica cinerea

H16 Calluna vulgaris-Arctostaphylos uva-ursi heath

E-central Scotland

Heather Calluna vulgaris, bearberry Arctostaphylos uva-ursi, bell heather Erica cinerea, cowberry Vaccinium vitis-idaea, various mosses/lichens, wavy hair-grass Deschampsia flexuosa

H18 Vaccinium myrtillus-Deschampsia flexuosa heath

Widespread, but especially N Scotland

Bilberry/blaeberry Vaccinium myrtillus, wavy hair-grass Deschampsia flexuosa, heath bedstraw Galium saxatile, various mosses

H21 Calluna vulgaris-Vaccinium myrtillus-Sphagnum capillifolium heath

Lake District, NW Scotland

Heather Calluna vulgaris, bilberry/blaeberry Vaccinium myrtillus, wavy hair-grass Deschampsia flexuosa, various mosses, tormentil Potentilla erecta

 

The fauna of upland heathland includes a variety of scarce and threatened bees, beetles, birds, butterflies, mammals, moths, reptiles and spiders. These include the moss carder-bee Bombus muscorum, the argent & sable moth Rheumaptera hastata ssp. nigrescens, the ring ouzel Turdus torquatus, and the mountain ringlet butterfly Erebia epiphron. Nevertheless, this habitat tends to lack the rich association of animals that characterises Lowland Heathland.