Circumpolar Arctic Vegetation Unit P1

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Hierarchy of Geobotanical Vegetation Map Units (Walker DA 2002)

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P1. 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. 1. Prostrate dwarf shrubs: Dryasⁿ; Salix arctica; Salix polaris; Salix rotundifolia; Salix phlebophylla;
   2. Sedge: Eriophorum triste; Carex rupestrisⁿ;
   3. Rush: Luzula confusa^a; Luzula nivalis^a; Juncus biglumis;
   4. Grass: Alopecurus alpinus^a; Deschampsia;
   5. Forb: Saxifraga hirculus; Saxifraga caespitosa^a; 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