Circumpolar Arctic Vegetation Unit P2


Hierarchy of Geobotanical Vegetation Map Units (Walker DA 2002)

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map legend color for unit P2P2. Prostrate/hemiprostrate dwarf-shrub tundra

Moist to dry tundra dominated by prostrate and hemiprostrate shrubs <15 cm tall, particularly Cassiope. Subzone C.

Detailed Description

Moist to dry tundra in acidic-bedrock portions of Subzone C where hemiprostrate dwarf-shrub (Cassiope tetragona) communities occupy a large portion of the landscape. In nonacidic areas Cassiope communities occur in sites with somewhat deeper than average winter snow cover. In acidic areas, Cassiope communities are dominant on zonal sites. This type is common on granite- and gneiss-bedrock of Svalbard, Greenland, Baffin Island, and Ellesmere Island. Plants cover 40-100% of the surface. The height of the plant canopy is 10-20 cm.
Area: 140 x 1000 km2.

Representative Syntaxa

Communities of the class Loiseleurio-Vaccinietea, e.g., Cassiopetum tetragonae (Böch. 1933) Dan. 1982 (Greenland, noncarbonate soil) and Carici-Kobresietea, e.g., Dryado-Cassiopetum tetragonae (Fries 1913) Hadac 1946 (Svalbard).

Dominant Plants

Prostrate and hemiprostrate dwarf shrubs, and mosses, rushes, forbs, and lichens.

    1. Prostrate and hemiprostrate dwarf shrubs: Cassiope tetragona; Dryasn; Rhododendron lapponicumn; Salix arctica; Salix polaris;
    2. Moss: Aulacomnium turgidum; Tomentypnum nitensn; Hylocomium splendens; Sanionia uncinata; Polytrichum juniperinum;
    3. Rush: Luzula confusaa; Luzula nivalisa;
    4. Forb: Oxyria digyna; Bistorta vivipara; Silene acaulis;
    5. Lichen: Peltigera apthosa; Cetrariella deliseii; Stereocaulon rivulorum; Solorina; Thamnolia;

a=acidic, n=non-acidic