Circumpolar Arctic Vegetation Unit W2

 

Hierarchy of Geobotanical Vegetation Map Units (Walker DA 2002)

North Slope coastal plain, Alaska. Photo D.A. Walker.
Enlarge image

map legend color for unit W2W2. Sedge, moss, dwarf-shrub wetland

Wetland complexes in the milder areas of the Arctic, dominated by sedges, grasses, and mosses, but including dwarf shrubs <40 cm tall. Subzone D.

Detailed Description

Wetland complexes of Subzone D, primarily fens with slightly acidic to circumneutral soil pH. Large components of moist nontussock sedge, dwarf-shrub, moss tundra (see Unit G3) are usually present in slightly elevated microsites such as hummocks and rims of low-centered ice-wedge polygons.
Area: 136 x 1000 km2.

Representative Syntaxa

Communities of the class Scheuchzerio-Caricetea.

Dominant Plants

Sedges, grasses, and mosses. Prostrate dwarf-shrubs and forbs are often present. Acidic variants on raised microsites have hypoarctic, oligotrophic dwarf shrubs (see also Unit G4 and Unit S1).

    1. Sedge: Carex aquatilis; Carex chordorrhiza; Carex rariflora; Eriophorum angustifolium; Eriophorum triste;
    2. Grass: Arctophila fulva; Dupontia fisheri;
    3. Moss: Pseudocalliergon brevifolius; Scorpidium scorpioides; Cinclidium latifolium; Meesia triquetra; Catoscopium nigritum; Distichium capillaceum;
    4. Prostrate dwarf shrubs: Salix arctica; Salix reptans; Salix fuscescens;
    5. Forb: Pedicularis sudetica ssp. albolabiata; Pedicularis pennellii; Comarum palustre;
    6. Hypoarctic, oligotrophic dwarf shrubs: Ledum; Salix pulchra; Empetrum; Betula nana s.l.; Vaccinium;

a=acidic, n=non-acidic