Habitat account - Natural and semi-natural grassland formations


6150 Siliceous alpine and boreal grasslands 

Background to selection

Distribution of SACs/SCIs/cSACs with habitat 6150 Siliceous alpine and boreal grasslands.  Click image for enlarged map.
Distribution of SACs/SCIs/cSACs with habitat 6150 Siliceous alpine and boreal grasslands. Click image for enlarged map.

Description and ecological characteristics

 

Siliceous alpine and boreal grasslands are one of the few predominantly near-natural habitats remaining in the UK. The habitat is the most extensive type of vegetation in the high mountain zone, i.e. above an altitude of about 750 m. It characteristically forms large continuous tracts, covering summit plateaux and the tops of the higher summits and ridges. The habitat comprises a range of grassland types whose composition is influenced by contrasting extremes of exposure and snow-lie. Late-lie snow-bed communities dominated by bryophytes and dwarf-herbs are also included within the definition of the habitat. The flora is characterised by a strong montane element which includes several uncommon vascular plants, mosses and liverworts. It is also the most important habitat for Eurasian dotterel Charadrius morinellus, Britain’s only montane wading bird. The habitat is vulnerable to nutrient inputs and physical damage such as occur due to dunging and urination by grazing animals, acid deposition, human and animal trampling, skiing and use of all-terrain vehicles.

 

There are seven main sub-types of Siliceous alpine and boreal grasslands recognised by the NVC, which are mostly referred to as ‘heath’ or snow-bed communities. These are:

 

     

  • U7  Nardus stricta – Carex bigelowii grass-heath
  • U8  Carex bigelowii – Polytrichum alpinum sedge-heath
  • U9  Juncus trifidus – Racomitrium lanuginosum rush-heath
  • U10  Carex bigelowii – Racomitrium lanuginosum moss-heath
  • U11  Polytrichum sexangulare – Kiaeria starkei snow-bed
  • U12  Salix herbacea – Racomitrium heterostichum snow-bed
  • U14  Alchemilla alpina – Sibbaldia procumbens dwarf-herb community

 

U10 Carex – Racomitrium moss-heath occurs on windswept ground blown clear of snow during winter, and is the most extensive sub-type of the habitat across most of the UK. Where snow-lie builds up, such moss-heath gives way initially to U7 Nardus – Carex grass-heath, and then to U8 Carex – Polytrichum sedge-heath where snow-lie is more prolonged. The longest lying snow-beds (U11 Polytrichum – Kiaeria snow-bed, U12 Salix – Racomitrium snow-bed and U14 Alchemilla – Sibbaldia dwarf-herb community) are dominated by mosses and hardy herbs. These communities occur around the edges of high plateaux on steep slopes where a snow cornice develops in high corries or in gullies where deep snow accumulates. They can also occur in snow hollows on the highest summits. The Alchemilla – Sibbaldia dwarf-herb community requires a certain amount of base-rich flushing to develop its distinctive flora of small herbs. Carex – Racomitrium moss-heath grades into U9 Juncus – Racomitrium rush-heath where exposure is more severe or the substrate unstable, and the latter community represents the habitat type at its highest altitude.

 

There is much variation in the distribution of the different sub-types across the country. In the western Highlands, Carex – Racomitrium moss-heath is widely distributed and extensive. In the east, Carex – Racomitrium moss-heath is proportionately less abundant, and Carex – Polytrichum sedge-heath and Juncus – Racomitrium rush-heath become more common, especially on the highest hills. Nardus – Carex grass-heaths are extensive throughout the Scottish Highlands, but to the south of the Highlands they become very local and the dominant form of the habitat is Carex – Racomitrium moss-heath. The late-lie snow patch communities (Polytrichum – Kiaeria snow-bed, Salix– Racomitrium snow-bed and Alchemilla– Sibbaldia dwarf-herb community) are rare, being restricted almost exclusively to the higher hills of the Highlands.

 

The most common sub-type, Carex – Racomitrium moss-heath, varies in species composition depending on the base-richness and instability of the substrate. On relatively stable and acid siliceous rocks the flora is typically species-poor, though a few cushion herbs occur locally, such as moss campion Silene acaulis and thrift Armeria maritima. Localised bands of base-rich rocks support a more varied flora, and a species-rich sub-community develops, supporting a number of rare or local montane plants. The flora of this species-rich moss-heath includes dwarf willow Salix herbacea, alpine lady’s-mantle Alchemilla alpina, moss campion Silene acaulis, thrift Armeria maritima, alpine bistort Persicaria vivipara, sibbaldia Sibbaldia procumbens, spiked wood-rush Luzula spicata, cyphel Minuartia sedoides, the rare montane calcicole mosses Aulacomnium turgidum and Hypnum hamulosum, and the rare foliose lichen Nephroma arcticum.

 

Open and unstable substrates can also produce an enrichment of the flora and give rise to a similar species-rich sub-type. This can develop on highly windswept ground but occurs most commonly on solifluction terracing in the Scottish Highlands. Alternate freezing and thawing of soil water forms the terracing. Many plants benefit from the instability, which stirs up the soils to release nutrients and counteracts the effects of leaching. A special feature in the UK is that strong winds at high altitude can keep the more exposed risers of the stair-like terraces open, resulting in distinctive bands of vegetation. Norwegian mugwort Artemisia norvegica, which is known from only two mountains in the North-west Highlands, is present in open Carex – Racomitrium moss-heath on solifluction terracing and on open basal rock surfaces.

 

The communities of the longest-lying snow patches (Polytrichum – Kiaeria snow-bed, Salix – Racomitrium snow-bed and Alchemilla – Sibbaldia dwarf-herb community) are dominated by a range of mosses and hardy herbs tolerant of prolonged snow-cover. Many rare species are found in these snow-beds, including hare’s-foot sedge Carex lachenalii, starwort mouse-ear Cerastium cerastoides, curved wood-rush Luzula arcuata, the bryophytes Conostomum tetragonum, Anthelia juratzkana and Moerckia blyttii, and many lichens growing on rocks or on the ground.

 

In the Scottish Highlands the sub-types of this habitat type tend to form intimate mosaics with other habitats, the elements of which are ecologically interdependent. For example, U18 Cryptogramma crispa – Athyrium distentifolium snow-bed community (a form of 8110 Siliceous scree of the montane to snow levels (Androsacetalia alpinae and Galeopsietalia ladani)) is often associated with snow-bed sub-types of Siliceous alpine and boreal grasslands. Similarly, U13 Deschampsia cespitosa – Galium saxatile grasslands, a non-Annex I habitat, can develop on slopes in association with moderately prolonged snow-cover and below areas of melting snow. A sub-type of this grassland with an abundance of the large hypnaceous moss Rhytidiadelphus loreus characteristically occurs in association with Carex – Racomitrium moss-heath on the edges of plateaux in the far north and west. Where there is a transition to more strongly base-rich soils 6170 Alpine and subalpine calcareous grasslands occur, including CG12 Festuca ovina – Alchemilla alpina – Silene acaulis dwarf-herb community and CG14 Dryas octopetala – Silene acaulis ledge community. The development of such associated communities adds to the diversity of sites supporting Siliceous alpine and boreal grasslands.

European status and distribution

 

Siliceous alpine and boreal grasslands have a restricted distribution in the EU. The UK and Ireland support the only examples of this vegetation within the Atlantic Biogeographical Region. Outside the EU, the sub-types dominated by woolly fringe-moss Racomitrium lanuginosum are restricted to oceanic, northern lands, such as the Faeroe Islands and Iceland.

UK status and distribution Click to view UK distribution of this habitat

 

In the UK extensive areas of Siliceous alpine and boreal grasslands occur chiefly in Scotland, but there are important southern outliers in northern England, north Wales and Northern Ireland, where the southern limit of the habitat in the EU is reached. In many of the southern outliers the extent of the habitat is smaller than on sites in Scotland and the degree of modification is often greater.

Site selection rationale

 

Sites have been selected to represent the geographical and ecological range of all of the sub-types of this habitat. The sites selected hold the most extensive areas of this habitat and include the widest range of sub-types. They are generally those which have been least modified by human activities, and as a result they demonstrate the best structure and function of the vegetation communities. Many sites support diverse vegetation mosaics and transitions to other communities.

 

Site selection has taken account of the UK’s responsibilities for conservation of this habitat type in the Atlantic Biogeographical Region. The sub-types dominated by woolly fringe-moss Racomitrium lanuginosum, which are the most widespread and abundant types in the UK, are particularly significant in international terms. The largest areas of Carex – Racomitrium moss-heath in the Scottish Highlands have therefore been included in the SAC series, together with important examples of southerly variants.


Site accounts

Beinn Dearg Highland
Beinn Dearg has the third-largest area of this habitat type in the UK and the second-largest in the north-west Highlands. There is extensive development of U7 Nardus strictaCarex bigelowii grass-heath and of both the species-poor and species-rich forms of U10 Carex bigelowiiRacomitrium lanuginosum moss-heath. The species-rich form is well-developed and reaches its second-largest extent within the SAC series on this site. Species-rich CarexRacomitrium moss-heath is associated with base-rich schist on extensive solifluction terracing. This is enriched with arctic-alpine and northern vascular plants, including moss campion Silene acaulis, cyphel Minuartia sedoides, three-leaved rush Juncus trifidus, spiked wood-rush Luzula spicata, sibbaldia Sibbaldia procumbens, dwarf cudweed Gnaphalium supinum and mountain everlasting Antennaria dioica, accompanied by the rare montane calcicole mosses Hypnum hamulosum and Aulacomnium turgidum. Beinn Dearg is one of only two mountains in the north-west Highlands on which the rare Norwegian mugwort Artemisia norvegica is known to occur. Moss- and dwarf-herb-dominated snow-bed communities (U11 Polytrichum sexangulareKiaeria starkei snow-bed, U12 Salix herbaceaRacomitrium heterostichum snow-bed and U14 Alchemilla alpinaSibbaldia procumbens dwarf-herb community) are well-represented but are not extensive.
Ben Alder and Aonach Beag Highland
These ranges of hills have the largest area of ground above 1000 m in Britain outside of the Cairngorms and the extent of Siliceous alpine and boreal grassland is correspondingly high. The range of communities is representative of the higher hills of the central Highlands, with all the NVC types associated with the habitat represented. The most extensive communities are U7 Nardus strictaCarex bigelowii grass-heath and U10 Carex bigelowiiRacomitrium lanuginosum moss-heath, the latter with an unusual occurrence of a species-rich sub-type following a band of high-altitude limestone. This site represents one of only six sites outside of the Cairngorms and Ben Nevis with extensive late-lie mossy snow-beds holding U11 Polytrichum sexangulareKiaeria starkei and U12 Salix herbaceaRacomitrium heterostichum snow-bed communities. Various rare plants occur in the snow-beds, including starwort mouse-ear Cerastium cerastoides and the bryophytes Dicranum glaciale, Marsupella condensata and Nardia breidleri. U8 Carex bigelowiiPolytrichum alpinum sedge-heath attains its largest extent outside of the eastern Highlands.
Ben Heasgarnich Perth and Kinross; Stirling
Ben Heasgarnich is the best representative for Siliceous alpine and boreal grassland of the Dalradian schist hills of the Breadalbane range. All the NVC types belonging to the habitat are represented, with U7 Nardus strictaCarex bigelowii grass-heath and U10 Carex bigelowiiRacomitrium lanuginosum moss-heath being the predominant communities on the high ground of the summits and summit ridges. The underlying schists are base-rich and Ben Heasgarnich is primarily of importance for supporting the largest extent in the SAC series of species-rich CarexRacomitrium moss-heath. This has an abundance of arctic-alpine species, such as moss campion Silene acaulis, mossy cyphel Minuartia sedoides, alpine bistort Persicaria vivipara and alpine meadow-rue Thalictrum alpinum. There are also some small but notably species-rich examples of late-lie snow-beds belonging to U14 Alchemilla alpinaSibbaldia procumbens dwarf-herb community. Moss-dominated snow-beds are well-represented but are of small extent.
Ben Nevis Highland
With the exception of Beinn Dearg and the Loch Maree Complex in the north, Ben Nevis has the most extensive development of Siliceous alpine and boreal grassland in the western Highlands. On the summit plateau of Aonach Mór U10 Carex bigelowiiRacomitrium lanuginosum moss-heath occurs as the highest extensive stand in the UK. The normal dominant Racomitrium lanuginosum is in part replaced on Aonach Mór by R. canescens (sensu lato), which provides affinities with the vegetation of Iceland and Jan Mayen. The R. canescens is associated with open, wind-blown sandy areas where there is active erosion and deposition of sand caused by the exceptionally high altitude and exposure. Other wind-eroded areas among CarexRacomitrium moss-heath may be colonised by three-leaved rush Juncus trifidus, and the national rarity curved wood-rush Luzula arcuata. Frequent arctic-alpines in the CarexRacomitrium moss-heath include least willow Salix herbacea, spiked wood-rush Luzula spicata, J. trifidus and moss campion Silene acaulis. U7 Nardus strictaCarex bigelowii grass-heath is extensive and occurs mostly in corries and in hollows on ridges where snow lies late. U8 Carex bigelowiiPolytrichum alpinum sedge-heath occurs on the higher summits where snow lies late in hollows and is more abundant on this site than on any other site in the western Highlands. These communities are associated with some of the most extensive moss-dominated late-lie snow beds (U11 Polytrichum sexangulareKiaeria starkei and U12 Salix herbaceaRacomitrium heterostichum snow-beds) outside of the Cairngorms.
Ben Wyvis Highland
Ben Wyvis is representative of the species-poor form of U10 Carex bigelowiiRacomitrium lanuginosum moss-heath of the north and west of Scotland. Although Siliceous alpine and boreal grasslands are not as extensive on Ben Wyvis as on some other hills, the site has the largest continuous single tract of this sub-type in the UK, covering almost the whole of the summit plateau. The habitat type is developed on base-poor schist. There is also a large extent of the associated Rhytidiadelphus loreus moss-rich grassland on the edges of the CarexRacomitrium moss-heath, where snow tends to drift. The site is little-disturbed and shows a particularly luxuriant moss-cover. U7 Nardus strictaCarex bigelowii grass-heath is also well-represented and U8 Carex bigelowiiPolytrichum alpinum sedge-heath is present locally. Late-lie moss- and dwarf-herb-dominated snow-bed communities (U11 Polytrichum sexangulareKiaeria starkei snow-bed, U12 Salix herbaceaRacomitrium heterostichum snow-bed and U14 Alchemilla alpinaSibbaldia procumbens dwarf-herb community) are represented on Ben Wyvis but are small in extent.
Caenlochan Aberdeenshire; Angus; Perth and Kinross
Caenlochan is representative of Siliceous alpine and boreal grasslands on high hills in the eastern Highlands. This is the most continental site in the series and is unique because it is the only site where the predominant community of the summit plateau is U8 Carex bigelowiiPolytrichum alpinum sedge-heath rather than the more widely predominant U10 Carex bigelowiiRacomitrium lanuginosum moss-heath. The extent of CarexPolytrichum sedge-heath is the largest of any site in the UK. The more characteristically oceanic CarexRacomitrium moss-heath is represented by some good stands but is not so extensive. U7 Nardus strictaCarex bigelowii grass-heath is also well-represented. There is a moderately large representation of late-lie snow-beds of U11 Polytrichum sexangulareKiaeria starkei snow-bed and U12 Salix herbaceaRacomitrium heterostichum snow-bed, while some small examples of U14 Alchemilla alpinaSibbaldia procumbens dwarf-herb snow-bed are also present on shelves on high ground.
Cairngorms Aberdeenshire; Highland; Moray
The Cairngorms complex (Cairngorms, eastern Cairngorms, Northern Corries and Inchrory) has the largest tracts of Siliceous alpine and boreal grasslands in the UK, developed on granite and, more locally, base-poor schist up to very high altitudes (above 1000 m). The total extent is more than twice that on any other site in the UK. The full range of sub-types on acidicsoils is well developed and they are widespread. Both U10 Carex bigelowiiRacomitrium lanuginosum moss-heath and U7 Nardus strictaCarex bigelowii grass-heath are extensive. The U9 Juncus trifidusRacomitrium lanuginosum rush-heath community is particularly well-developed, becoming predominant on the higher plateau, and its extent far exceeds that on any other site in the UK. The stands of U8 Carex bigelowiiPolytrichum alpinum sedge-heath are among the most extensive in the UK. The late-lie moss snow-beds (U11 Polytrichum norvegicumKiaeria starkei snow-bed and U12 Salix herbaceaRacomitrium heterostichum snow-bed) are the most extensive and well-developed in Britain. The U14 Alchemilla alpinaSibbaldia procumbens dwarf-herb community is also well-represented.
Creag Meagaidh Highland
Creag Meagaidh has an extensive high plateau with schistose rocks similar to those on Drumochter Hills. The site contains a large area of Siliceous alpine and boreal grasslands with the full range of community types characteristic of the central Highlands. U10 Carex bigelowiiRacomitrium lanuginosum moss-heath is the dominant type on the high plateau, while the species-rich sub-type is also represented as small stands, mostly in association with solifluction terracing. There are large stands of U7 Nardus strictaCarex bigelowii grass-heath and U8 Carex bigelowiiPolytrichum alpinum sedge-heath is extensive on the summit of Creag Meagaidh. U9 Juncus trifidusRacomitrium lanuginosum rush-heath is developed locally on exposed ridges. Despite the similarity of rock type, the proportions of the communities present on Creag Meagaidh are different from those on Drumochter Hills. The dominance of CarexRacomitrium moss-heath on Creag Meagaidh is probably due to a more oceanic climate, while the smaller extent of NardusCarex grass-heath and CarexPolytrichum sedge-heath compared with Drumochter Hills is due to less prolonged snow cover on the high plateau. There are transitions to extensive late-lie moss-dominated snow-bed communities (U11 Polytrichum sexangulareKiaeria starkei snow-bed and U12 Salix herbaceaRacomitrium heterostichum snow-bed) and flushed U13 Deschampsia cespitosaGalium saxatile grassland. U14 Alchemilla alpinaSibbaldia procumbens dwarf-herb community is also represented.
Drumochter Hills Highland; Perth and Kinross
Drumochter has an extensive high plateau with the fourth-largest extent in the SAC series of Siliceous alpine and boreal grasslands, including the second-largest area of U8 Carex bigelowiiPolytrichum alpinum sedge-heath. Two other sub-types, U10 Carex bigelowiiRacomitrium lanuginosum moss-heath and U7 Nardus strictaCarex bigelowii grass-heath, are extensive. The site is representative of the central Highlands where schistose rocks predominate, supporting local enrichment of the flora. This contrasts with the wholly acidic granite of the Cairngorms. The comparatively large extent of CarexPolytrichum sedge-heath is characteristic of the high eastern and central hills. There are especially fine transitions to alpine dwarf-shrub heaths, and unusually the grassland borders extensive high-altitude blanket mire. Late-lie snow-beds of U11 Polytrichum sexangulareKiaeria starkei snow-bed and U12 Salix herbaceaRacomitrium heterostichum snow-bed communities are well-developed but are not extensive.
Eryri/ Snowdonia Conwy; Gwynedd
Snowdonia has the best-developed and most extensive areas of Siliceous alpine and boreal grasslands in Wales and is the largest example of the habitat type south of Scotland. The principal sub-type present is U10 Carex bigelowiiRacomitrium lanuginosum moss-heath, but there are also fragments of U7 Nardus strictaCarex bigelowii grass-heath. This site is representative of the more impoverished southern variants of the habitat type.
Fannich Hills Highland
Siliceous alpine and boreal grasslands are represented at Fannich Hills by NVC types U7 Nardus stricta–Carex bigelowii grass-heath, U10 Carex bigelowii–Racomitrium lanuginosum moss-heath, U11 Polytrichum norvegicum–Kiaeria starkei snow-bed, U12 Salix herbacea–Racomitrium heterostichum snow-bed and U14 Alchemilla alpina–Sibbaldia procumbens dwarf-herb community. These types are representative of the higher hills of the western Highlands, and well represent differing conditions of snow-lie. The range of types is similar to other sites in the region but Fannich Hills supports more extensive tracts of the oceanic U10 Carex–Racomitrium moss-heath which covers much of the high plateaux and summits. The species-poor typical sub-community (U10b) with carpets of woolly fringe-moss Racomitrium lanuginosum covering the ground is well-developed. Most significant is the species-rich sub-type of Carex–Racomitrium moss-heath belonging to the Silene acaulis sub-community (U10c), which is exceptionally extensive at Fannich Hills.

The flora of the Siliceous alpine and boreal grasslands is rich and includes many montane species and national rarities such as alpine lady’s-mantle Alchemilla alpina, three-leaved rush Juncus trifidus, dwarf willow Salix herbacea, mountain everlasting Antennaria dioica, spiked wood-rush Luzula spicata, dwarf cudweed Gnaphalium supinum, alpine bistort Persicaria vivipara, moss campion Silene acaulis, cyphel Minuartia sedoides, sibbaldia Sibbaldia procumbens, trailing azalea Loiseleuria procumbens and alpine bearberry Arctostaphylos alpina. The rare mosses Aulacomnium turgidum, Polytrichum sexangulare and Dicranum starkei are also represented. Montane lichens include a number of characteristic species: Solorina crocea, Thamnolia vermicularis, Cetraria islandica and Ochrolechia frigida.
Lake District High Fells Cumbria
Siliceous alpine and boreal grasslands are widely distributed through the Lake District High Fells above 700 m. The acidic rocks are of the Borrowdale Volcanic series and Skiddaw Slates. Some of the summits (particularly Helvellyn and Skiddaw) have frequent areas of disturbed ground due to frost-heave and solifluction. The NVC type present is the species-poor U10 Carex bigelowiiRacomitrium lanuginosum moss-heath. Wavy hair-grass Deschampsia flexuosa and sheep’s fescue Festuca ovina dominate the sward, with bilberry Vaccinium myrtillus, woolly fringe-moss Racomitrium lanuginosum, stiff sedge Carex bigelowii, fir clubmoss Huperzia selago and the lichens Cladonia uncialis, C. coccifera, C. squamosa, C. subcervicornis, Cornicularia aculeata and Cetraria islandica. Dwarf willow Salix herbacea, R. lanuginosum and alpine clubmoss Diphasiastrum alpinum can be locally abundant, the latter particularly where there is late snow-lie.
Loch Maree Complex Highland
The Loch Maree Complex represents Siliceous alpine and boreal grasslands in the highly oceanic and heavily glaciated hills of the north-west Highlands. Both acid and calcareous sub-types are represented at moderately high altitude. The characteristically oceanic U10 Carex bigelowiiRacomitrium lanuginosum moss-heath is the most extensive and well-developed type, and includes both species-poor and species-rich sub-types with arctic-alpines and rare montane mosses well-represented. There is a relatively small representation of the snow-bed communities U7 Nardus strictaCarex bigelowii grass-heath and U14 Alchemilla alpinaSibbaldia procumbens dwarf-herb community. There are well-developed transitions to snow-beds dominated by the moss Rhytidiadelphus loreus (assignable to U13 Deschampsia cespitosaGalium saxatile grassland).
Merrick Kells Dumfries and Galloway; East Ayrshire; South Ayrshire
Merrick Kells holds the best developed areas of Siliceous alpine and boreal grasslands in the Southern Uplands of Scotland. This is the largest area of the habitat type south of the Highlands within the SAC series. Species-poor U10 Carex bigelowiiRacomitrium lanuginosum moss-heath is the main sub-type and is well-developed, with a high cover of woolly fringe-moss Racomitrium lanuginosum. The accompanying U7 Nardus strictaCarex bigelowii grass-heath is one of the best representations south of the Highlands in terms of vegetation structure and floristics, although small in area. This occurrence of the habitat type is comparable with southern outliers on the hills of England and Wales.
Moffat Hills Dumfries and Galloway
Moffat Hills represents Siliceous alpine and boreal grassland in the central Southern Uplands. The main type represented is U10 Carex bigelowiiRacomitrium lanuginosum moss-heath which covers the higher summits, including solifluction ground. This is some of the best-developed CarexRacomitrium moss-heath occurring south of the Highlands, though loss of Racomitrium cover may have occurred due to grazing. The moss-heath is grassy, and contains much sheep’s-fescue Festuca ovina and wavy hair-grass Deschampsia flexuosa together with the small herb heath bedstraw Galium saxatile. The frequency of these species is probably an indication of nutrient enrichment from grazing sheep. The snow-bed U7 Nardus strictaCarex bigelowii grass-heath is widespread here, at one of its few sites south of the Highlands.
Moor House - Upper Teesdale Cumbria; Durham
The summit of Cross Fell has the best-developed and most extensive area of Siliceous alpine and boreal grasslands in England. The U10 Carex bigelowiiRacomitrium lanuginosum moss-heath that covers the summit cap has a high cover of woolly fringe-moss Racomitrium lanuginosum.
North Harris Western Isles / Na h-Eileanan an Iar
North Harris represents an outlier of Siliceous and alpine boreal grassland on the Outer Hebrides in the far north-west of the UK. Two NVC types are present (U10 Carex bigelowiiRacomitrium lanuginosum moss-heath and U7 Nardus strictaCarex bigelowii grass-heath), representing respectively the chionophobous and chionophilous aspects of the habitat in the Outer Hebrides. The mat-grass Nardus snow-beds are only moderately extensive, but CarexRacomitrium moss-heath has one of its largest extents outside of the Cairngorms, demonstrating its dominance at higher levels in the cool, oceanic climate.
Strathglass Complex Highland
The Affric-Cannich Hills within Strathglass Complex have the second-largest extent of Siliceous alpine and boreal grasslands in the UK, and are representative of the habitat type in the north-west Highlands. The rocks are generally acidic, with small areas of moderately base-rich rock. The dominant sub-types present are species-poor U10 Carex bigelowiiRacomitrium lanuginosum moss-heath and U7 Nardus strictaCarex bigelowii grass-heath. Small areas of U8 Carex bigelowiiPolytrichum alpinum sedge-heath and U9 Juncus trifidusRacomitrium lanuginosum rush-heath are also represented. There are extensive areas of the rarer species-rich CarexRacomitrium moss-heath chiefly associated with the disturbed ground of solifluction terracing. This is enriched with arctic-alpine vascular plants and rare montane calcicole mosses. Associated communities include the most extensive areas of U13 Deschampsia cespitosaGalium saxatile grassland in Britain. The moss- and dwarf-herb-dominated late-lie snow-beds (U11 Polytrichum sexangulareKiaeria starkei snow-bed, U12 Salix herbaceaRacomitrium heterostichum snow-bed and U14 Alchemilla alpinaSibbaldia procumbens dwarf-herb community) are well-represented.

SACs/SCIs/cSACs where this Annex I habitat is a qualifying feature, but not a primary reason for site selection

Beinn a`Ghlo Perth and Kinross
Beinn Bhan Highland
Ben Lawers Perth and Kinross
Ben Lui Argyll and Bute; Stirling
Eastern Mournes Down
Foinaven Highland
Glen Coe Highland
Inverpolly Highland
Meall na Samhna Stirling
North Pennine Moors Cumbria; Durham; Northumberland; North Yorkshire
Trotternish Ridge Highland
 

Many designated sites are on private land: the listing of a site in these pages does not imply any right of public access.