CITATION GARBH CHOIRE SITE OF SPECIAL SCIENTIFIC INTEREST Aberdeenshire Site code: 670

NATIONAL GRID REFERENCE: NO174786

OS 1: 50 000 SHEET NO: Landranger Series 43 1: 25 000 SHEET NO: Explorer Series 387

AREA: 229.3 hectares

NOTIFIED NATURAL FEATURES

Biological : Uplands : Upland assemblage : Alpine flushes : Snowbed : Fens : Spring-head, rill and flush : Vascular : Vascular assemblage Non-vascular plants : Bryophyte assemblage

DESCRIPTION

Garbh Choire is situated on the north side of Glas Maol, about 12 km south of Braemar. It comprises two hollows, gouged out by glacial action, on the edge of the Caenlochan plateau. Its steep, scree-mantled sides rise in altitude from 700 m to over 1000 m.

The geology of the corrie is predominately schists, both base-rich and acidic varieties, with bands of calcareous rock amongst some of the granitic schists. Two local bodies of basic metamorphic rock are locally exposed in the more southern of the two hollows. Minerals from these rocks contribute to the fertility of the soils in the corrie and, in turn, the richness and diversity of the site’s montane habitats and flora.

Garbh Choire is important for its assemblage of montane habitats and for the assemblages of vascular plants and bryophytes (mosses and liverworts), that these habitats support. The assemblage of habitats includes important examples of different types of snow-bed vegetation and springs and flushes, as well as moss- heath, alpine heath and blanket bog.

HABITATS

Upland assemblage

The vegetation of the corrie is a complex mosaic of many habitats. The distribution of these habitats is influenced by local variations of factors such as altitude, slope exposure, drainage and duration of snow lie, as well as variation in the underlying geology. The complexity and diversity of habitats within a relatively small area contributes to the overall interest of the site.

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Alpine heath, moss-heath and related vegetation

On the most exposed parts of the site such as along the ridge at the edge of the plateau and slopes of Cairn of Claise, the vegetation is predominately a mix of grass- heath and rush-heath communities adapted to harsh, high-altitude conditions. Characteristic species here are the three-leaved rush Juncus trifidus, woolly hair- moss Racomitrium lanuginosum and stiff sedge .

In very exposed areas below the ridge a dwarfed heath community is present, distinguished by blaeberry Vaccinium myrtillus, mountain crowberry Empetrum nigrum ssp hermaphroditum, trailing azalea Loiseleuria procumbens and abundant Cladonia lichens.

Snow-beds and related vegetation

A wide range of types of snow-bed vegetation are found, according to the length of snow lie. These include communities characterised by sedges, grasses and bryophytes, as well as related vegetation types with dwarf-herbs and ferns.

Sedge-heath and especially grass-heath communities of mat grass Nardus stricta, stiff sedge C. bigelowii and the moss Polytrichum alpinum, associated with relatively short periods of snow lie, are extensive. These extend from the top of the corrie down to the mid and lower slopes, particularly in ill-drained hollows where snow accumulates.

Snow beds tend to be deepest towards the top of the corrie where snow blown off the plateau collects. In areas of very late snow lie in the southern hollow a high-altitude snow-bed community characterised by the mosses Polytrichum sexangulare and Kiaeria starkei is present very locally but well developed.

Banks irrigated by melt water from snow-beds support a species-rich dwarf-herb community characterised by alpine lady’s mantle Alchemilla alpina and least cinquefoil Sibbaldia procumbens. One rare variant of this community occurs in basic- rich areas where water seeps from seams of calc-silcate rock and runs over the ground surface, giving rise to the most species-rich vegetation in the corrie. This community is a locus for a number of rare vascular plants and bryophytes.

The steepest areas of the corrie walls are covered by bare scree. Parsley fern Cryptogramma crispa grows amongst the rocks, alongside tufted hair grass Deschampsia cespitosa and heath bedstraw Galium saxatile.

Springs and flushes

Acidic flushes are widespread in the corrie on base-poor soils and are characterised by sedges and sphagum mosses, particularly the white sedge Carex curta and the bog moss Sphagnum russowii. A variant of this mire, found at high altitude on the ridge at the top of the corrie, supports the montane form of water sedge Carex aquatilis and the mountain bog sedge Carex rariflora.

Page 2 of 4 A327402.DOC Base-rich flush communities of high altitudes are well developed and comprise a relatively open community characterised by yellow saxifrage Saxifraga aizoides, especially along water-tracks and more closed swards of small-sedges in mixture with ‘brown mosses’. These are the habitat of a number of arctic-alpines including Scottish asphodel Tofieldia pusilla, three-flowered rush Juncus triglumis and sheathed sedge Carex vaginata. This site and the adjacent Caenlochan SSSI together have some of the best examples of this rare habitat in the United Kingdom.

Garbh Choire has a large number of montane springs and associated vegetation throughout the altitudinal range of the corrie, including those associated with areas of late snow-lie. Of particular note is the nationally rare type of spring characterised by the moss Pohlia wahlenbergii var. glacialis and the liverwort Anthelia julacea.

SPECIES

Plants

The assemblages of vascular plants includes the nationally rare mountain bog sedge Carex rariflora and a number of nationally scarce species such as the eyebright Euphrasia frigida, alpine speedwell Veronica alpina, alpine pearlwort Sagina saginoides, alpine catstail alpinum, sheathed sedge Carex vaginata, russet sedge Carex saxatilis and chestnut rush Juncus castaneus.

The assemblage of rare and scarce bryophyte includes several nationally rare species, such as the mosses Bryum stirtonii, Mnium spinosum and Plagiomnium medium, and various national scarce species, for example the mosses Sphagnum lindbergii, Hylocomium pryenaicum and Oncophorus virens and the liverworts Barbilophozia lycopodioides and Lophozia obtusa.

NOTIFICATION HISTORY

First notified, under the 1981 Act: 15 March 1996. Reviewed under the 2004 Act: 6 June 2011.

REMARKS

Measured area of site corrected (from 229 ha).

Garbh Choire SSSI is part of Caenlochan Special Area of Conservation (SAC), which is designated for the European habitats listed below and is also part of the Cairngorms Massif Special Protection Area (SPA), which is designated for golden eagle. Those habitats highlighted by an asterisk are most relevant to the area of this SSSI.

Habitats: Alpine and subalpine heaths* Base-rich fens* Base-rich scree Blanket bog* Dry heaths Grasslands on soils rich in heavy metals

Page 3 of 4 A327402.DOC High-altitude plant communities associated with areas of water seepage* Montane acid grasslands* Mountain willow scrub Plants in crevices on acid rocks Plants in crevices on base-rich rocks Species-rich grassland with mat-grass in upland areas Tall herb communities

Birds: Golden eagle Aquila chrysaetos

The lower reaches of the Allt a’Garbh-choire form part of the River Dee SAC which is designated for the following European species. Those highlighted by an asterisk are most relevant to the area of this SSSI.

Species: Atlantic salmon Salmo salar* Freshwater pearl mussel Margaritifera margaritifera Otter Lutra lutra*

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