Circumpolar Arctic Vegetation Unit B3


Hierarchy of Geobotanical Vegetation Map Units (Walker DA 2002)

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map legend color for unit B3B3. Noncarbonate mountain complex

Mountain vegetation on noncarbonate bedrock. The variety and size of plants decrease with elevation and latitude. Hatching color and code indicate the bioclimate subzone at the mountain base. B3a through B3e indicate subzones A through E; B3n indicates noncarbonate nunatak areas.

Detailed Description

Dry acidic tundra complexes on mountains and plateaus with noncarbonate bedrock. Vegetation changes with elevation in the mountains, forming elevation belts whose vegetation is physiognomically similar to that of bioclimate subzones with comparable summer climate (see the elevation belt). The color of the polygon hatch pattern denotes the bioclimate subzone at the base of the mountains. For example B3a occurs in Subzone A, B3b in Subzone B, etc. B3n denotes nunatak areas, with many noncarbonate mountain peaks surrounded by glaciers. Mesic zonal microsites are relatively uncommon. More common are plant communities growing on wind-swept, rocky ridges, screes, and dry fell-fields, alternating with snowbed plant communities.
Area: 625 x 1000 km2.

Representative Syntaxa

Belt a in Subzone B, cf. Papaveretum dahliani Hofm. 1968, in subzones C-E Papaveretum radicatae Dierss. 1992 (both Thlaspietea rotundifolii); Belt b, Carici-Dryadetum integrifoliae Dan. 1982 (Carici-Kobresietea Ohba 1974); Elevation Belt c, e.g., Cassiopetum tetragonae (Böch. 1933) Dan. 1982 (Loiseleurio-Vaccinietea Eggl. 1952 em. Schub. 1960); Belt d, Empetrum-Vaccinium community Dan. 1982 or Empetro - Betuletum nanaeNordh. 1943, and Belt e, Betulo-Salicetum glaucae prov. Dan. 2002 (all Loiseleurio-Vaccinietea) (Greenland).