The Alaska Vegetation Classification - Alaska Geobotany Center ...

Figure 56Crowberry tundra dominated b) I Empsirumnigrum with Carex spp. and Calamagrosiis nurkaonsis inthe Aleutian Islands.Dlstrlbutlon and slte characterlstlcs-These communities are common in theAleutian Islands and northwestern, southwestern, and south-central Alaska on slopesand level ground. They become infrequent east of Prince William Sound, apparentlybeing replaced by mountain-heath dwarf shrub tundra communities. Soils are variable,ranging from thin well-drained mineral soil (most common in western Alaska andwindswept Aleutian localities) to rather poorly drained peats. The peat is generallyless than 30 centimeters (12 in) thick and often is broken by bedrock outcrops.Permafrost is present at depths of 30 to 60 centimeters (12 to 24 in) at most westernand southwestern sites but is absent elsewhere.Successlonal status-Successional relations are unknown, but crowberry tundracommunities occupy large areas and appear to be stable.Closely related types-Crowberry dwarf shrub tundra can be similar to all otherdwarf shrub types, especially the ericaceous ones, but has more Empetrum nigrum.It also is similar Io some ericaceous scrub bog communities but occurs on thin peakand has little or no sphagnum. Some western Alaska stands may resemble mesicshrub birch-ericaceous scrub communities, or even mixed shrub-sedge tussocktundra communities, but have more crowberry and lack sedge tussocks and shrubbirch.Photographs-Figure 56, this publication.Prlmary references-Bos 1967, Byrd 1984, Cooper 1942, Everett 1971, Griggs1936.Communities-Empetrum nigrum-Cassiope stelleriana-Phyllodoce aleutica-Vaccinium spp. (Cooper 1942, Fox 1983, Heusser 1960, lsleib and Kessel 1973,Palmer 1942). Empetrum nigrum-Vaccinium spp. (Friedman 1982, Griggs 1936,Racine and Young 1978). Empetrum nigrum-Lycopodium spp./Bracbytheciumalbicans-Cladonia spp. (Bank 1951). Empetrum nigrum-Carexpluriflora-C. macrochaeta/Cladonia spp. (Bank 1951, Everett 1971, Hulth 1960, Shackletteand others 1969). Empetrum nigrum-Cassiope lycopodioides-Carex circinnata/mosses (Byrd 1984). Empetrum nigrum-Arctostaphybs alpina (60s 1967, Fries1977). Empetrum nigfum-Vaccinium uliginosum (HultBn 1962). Empetrum nigrum-Carex 6igelowii-Arcfostaphylos alpina (Bos 1967). Empetrum nigwm-Salix arctica-Cetraria spp. (Young and Racine 1978).154