Arctostaphylos alpinus

Tracheophyta MagnoliopsidaEricaceaeArctostaphylosArctostaphylos alpinus

Ecology

A strictly calcifugous shrub growing on acidic mineral soils or peat. It occurs on exposed upland heath, and in the northern Highlands of Scotland also on drier blanket bog. It is possibly long-lived, and fruiting is often sparse. It mostly occurs at mid-elevations, but descends to 100 m in North Roe (Shetland) and ascends to 945 m on Tom a`Choinich above Glen Affric (Easterness).

Status

Native

World Distribution

Circumpolar Arctic-montane element.

Broad Habitats

Montane habitats (acid grassland and heath with montane species)

Light (Ellenberg): 7

Moisture (Ellenberg): 6

Reaction (Ellenberg): 2

Nitrogen (Ellenberg): 2

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 1.6

July Mean Temperature (Celsius): 11.6

Annual Precipitation (mm): 1750

Height (cm): 20

Perennation - primary

Perennial

Life Form - primary

Chamaephyte

Woodiness

Woody

Clonality - primary

Extensively creeping and rooting at nodes

Count of 10km squares in Great Britain: 134

Count of 10km squares in Ireland: 0

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: -0.22

JNCC Designations

NHMSYS0000456035

Scarce Atlas Account

Scarce Atlas Account: 

Arctostaphylos alpinus (L.) Sprengel

Mountain bearberry

Status: scarce

The best known habitat for this plant is on dry, windswept ridges and moraines at about 600 metres altitude (Raven & Walters 1956). In this montane heath habitat its associates include prostrate Calluna vulgaris, Carex bigelowii, Empetrum nigrum subsp. hermaphroditicum, Loiseleuria procumbens, Salix herbacea, Racomitrium lanuginosum and lichens. Where the vegetation becomes taller, A. alpinus tends to disappear. In the northern Highlands it also grows in undisturbed blanket bog with Betula nana, Calluna vulgaris and Eriophorum vaginatum (McVean & Ratcliffe 1962). In all its Scottish habitats, A. alpinus is a strict calcifuge, growing on acidic mineral or peat substrates. It is mainly a middle elevation plant, but reaches at least 945 metres on Tom a'Choinich above Glen Affric, and descends to 130 metres in Sutherland.

A. alpina is a woody perennial, possibly with a long life-span, flowering in May or June before the leaves expand. The white bell-flowers are small and have small openings so that self-pollination may be the rule (Raven & Walters 1956). Fruits ripen in late July or August, but crops are commonly sparse. The plant is partially deciduous, many leaves displaying brilliant scarlet autumn colours and some surviving the winter. As the winter winds remove snow from its habitat, it may be left vulnerable to grazing. Bird-carried berries are possibly the source of new populations.

There is little evidence for a widespread decline of this species, which is probably still present in most of the 10 km squares for which only pre-1970 records are available. However, it appears to retreat when its habitats are burned, recovering only slowly after moorland fires.

A. alpina has a typical arctic-alpine distribution, occurring widely in Fennoscandia, through the Eurasian Arctic and in North America and Greenland. Southwards it reaches the Alps, Pyrenees and New Hampshire mountains.

The south-eastern edge of the plant's distribution closely follows the mean July isotherm for 14.5°C. Horticulturists find difficulty with the plant to the east of this isotherm (R. Macbeath pers. comm.), A few outlying colonies occur but at a higher altitude. The less distinct western edge runs near the mean January isotherm for 4°C, which passes through Skye near Kylerhea, where J. Lightfoot found the plant in 1772. Further attempts to find the species here failed until it was rediscovered by Mrs C. W. Murray in 1990 (Murray 1991).

 

A. Slack

Atlas text references

Atlas (194a) Hultén E, Fries M
1986.  Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols. Meusel H, Jäger E, Rauschert S, Weinert E
1978.  Vergleichende Chorologie der zentraleuropäischen Flora. Volume 2. 2 vols. Stewart A, Pearman DA, Preston CD
1994.  Scarce plants in Britain.