Circumpolar Arctic Vegetation Unit P1

 

Hierarchy of Geobotanical Vegetation Map Units (Walker DA 2002)

Bunde Fjord, Axel Heiberg Island, Canada. Photo D.A. Walker.
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map legend color for unit P1P1. Prostrate dwarf-shrub, herb tundra

Dry tundra with patchy vegetation. Prostrate shrubs <5 cm tall (such as Dryas and Salix arctica) are dominant, with graminoids and forbs. Lichens are also common. Subzone B and Subzone C.

Detailed Description

Dry tundra of the Middle Arctic (sensu Polunin 1951; polar semideserts of Bliss 1997). This is the zonal vegetation of Subzone B and also covers large dry areas in Subzone C. The vegetation is open or patchy (20-80% cover), with plants 5-10 cm tall. Vascular plants cover about 5-25%, lichens and mosses cover 30-60%. On nonacidic substrates of Subzone B the dominant zonal vegetation is Dryas - Salix arctica communities; on acidic substrates it is Luzula - Salix arctica.
Area: 399 x 1000 km2.

Representative Syntaxa

Communities of the class Carici-Kobresietea, e.g., Carici-Dryadetum integrifoliae Dan. 1982 ( Greenland, North America), and Loiseleurio-Vaccinietea , e.g., Gymnomitrio-Loiseleurietum Dan. 1982 (Greenland).

Dominant Plants

Prostrate dwarf-shrubs are dominant. Other common plants include sedges, rushes, grasses, forbs, and lichens. In Subzone C this vegetation is much richer in vascular species, particularly sedges, grasses, and forbs.

    1. Prostrate dwarf shrubs: Dryasn; Salix arctica; Salix polaris; Salix rotundifolia; Salix phlebophylla;
    2. Sedge: Eriophorum triste; Carex rupestrisn;
    3. Rush: Luzula confusaa; Luzula nivalisa; Juncus biglumis;
    4. Grass: Alopecurus alpinusa; Deschampsia;
    5. Forb: Saxifraga hirculus; Saxifraga caespitosaa; Saxifraga oppositifolian; Novosieversia glacialisn; Oxytropisn;
    6. Moss: Ditrichum flexicaulen; Distichiumn; Sanionia uncinata; Encalypta; Pohlia; Polytrichum; Hylocomium splendens; Aulacomnium turgidum; Tomentypnum nitensn;
    7. Lichen: Thamnolia; Flavocetraria;

a=acidic, n=non-acidic