Introduction
Barren Complexes: B2.1B2.1 Lichens on Lava (Seward Peninsula) - B3d.1B3d.1 Acidic mountain complexes (St. Lawrence Is.) - B3e.1B3e.1 Acidic mountain complexes (Brooks Range) - B3e.2B3e.2 Acidic mountain complexes (NW Alaska) - B3e.3B3e.3 Acidic mountain complexes (Kuskokwim Mtns.) - B4d.1B4d.1 Nonacidic mountain complexes (Seward Peninsula) - B4d.2B4d.2 Nonacidic mountain complexes (St. Lawrence Is.) - B4e.1B4e.1 Nonacidic mountain complexes (Brooks Range) - B4e.2B4e.2 Nonacidic mountain complexes (NW Alaska)
Non-Tussock Graminoid Tundras: G3.1G3.1 Moist nonacidic tundra (N. Arctic Coastal Plain) - G3.2G3.2 Moist nonacidic tundra (St. Lawrence Is.) - G3.3G3.3 Moist nonacidic tundra (Arctic Foothills, Seward Peninsula)
Tussock Graminoid Tundras: G4.1G4.1 Tussock tundra (entire map) - G4.2G4.2 Lichen-rich tussock tundra (Seward Peninsula) - G4.3G4.3 Tussock tundra on sands (Arctic Coastal Plain)
Prostrate Dwarf-Shrub Tundras: P2.1P2.1 Dry tundra (St. Matthew Is.)
Erect Dwarf-Shrub Tundras: S1.1S1.1 Shrubby, tussock tundra (NE Alaska) - S1.2S1.2 Dwarf-shrub, lichen tundra (NW Alaska) - S1.3S1.3 Dwarf-shrub tundra on volcanic rock (Yukon-Kuskokwim Delta) - S1.4S1.4 Dwarf-shrub, lichen tundra (Kuskokwim Mtns.)
Low-Shrub Tundras: S2.1S2.1 Willow-birch tundra (entire map) - S2.2S2.2 Alder shrublands (entire map)
Wetlands: W1.1W1.1 Wet acidic coastal complex (N Alaska) - W1.2W1.2 Wet nonacidic coastal complex (N Alaska) - W2.1W2.1 Wet acidic complex (N Alaska, Seward Peninsula) - W2.2W2.2 Wet nonacidic complex (Subzone D, N Alaska) - W3.1W3.1 Wet acidic complex with tussock tundra (W Alaska) - W3.2W3.2 Wet acidic complex with dwarf-shrub tundra (lower parts of Yukon-Kuskokwim Delta) - W3.3W3.3 Wet acidic complex with low-shrub tundra (Yukon-Kuskokwim Delta) - W3.4W3.4 Wet acidic complex with dwarf-shrub tundra (inland parts of Yukon-Kuskokwim Delta) - W3.5W3.5 Wet acidic complex (Nunivak Is.) - W3.6W3.6 Wet nonacidic complex (warmer parts of NW Alaska) - W3.7W3.7 Wet coastal saline tundra (Yukon-Kuskokwim Delta)

B2.1 Lichens on lava (Seward Peninsula)

Lichen communities (comm. 74) on recent lava flows, complexed with unvegetated lava; in mosaic with areas not covered by lava (G3.3, comm. 75). Seward Peninsula, Subzone E.

(See G3.3)

Plant Communities:

Community 74:

Rock desert, Lava A,B,C (Raynolds et al. 2002) (Seward Peninsula).

Lichen: Umbilicaria spp., Rhizocarpon geographicum, Cladonia stellaris;
Dwarf shrub: Loiseluria procumbens

Community 75:

Northern Beringian Islands: Dryado integrifoliae-Caricetum bigelowii, moist calcareous tundra (Walker et al. 1994) (Toolik Lake).

Beringian Alaska: Vegetation type Bigelow's sedge tussock dwarf-shrub tundra (Racine and Anderson 1979); Releves R6,7a,33,37,57,58 (Raynolds et al. 2002) (Seward Peninsula).

Vegetation type Bigelow's sedge tussock dwarf-shrub tundra (Racine and Anderson 1979); Releves R6,7a,33,37,57,58 (Raynolds et al. 2002) (Seward Peninsula).

Sedges: Carex bigelowii, Eriophorum angustifolium ssp. triste, Carex membranacea, E. vaginatum;
Prostrate dwarf shrub: Dryas integrifolia, Salix reticulata, Arctous rubra;
Erect dwarf shrub: Salix richardsonii, S. glauca, Vaccinium uliginosum, Rhododendrum lapponicum;
Forb: Lupinus arcticus, Oxytropis maydelliana, Pedicularis capitata, Lagotis glauca, Eutrema edwardsii, Tephroseris frigida, Bistorta vivipara, Packera cymbalaria, Pedicularis lanata, Tofieldia pusilla;
Horsetail: Equisetum arvense, Equisetum variegatum;
Moss: Tomentypnum nitens, Hylocomium splendens, Aulacomnium turgidum;
Lichen: Thamnolia subuliformis, Flavocetraria spp., Dactylina arctica