Circumpolar Arctic Vegetation Unit B1
- CAVM
- Vegetation
- About the Vegetation Map Units
- Bioclimate Subzones
- Floristic Provinces
- AVHRR
- Elevation
- Lake Cover
- Physiography
- NDVI and Phytomass
- Substrate Chemistry
- Coastline
- Literature
Barrens:
B1B1. Cryptogam, herb barren -
B2B2. Cryptogam barren complex (bedrock) -
B3B3. Noncarbonate mountain complex -
B4B4. Carbonate mountain complex ||
Graminoid Tundras:
G1G1. Rush/grass, forb, cryptogam tundra -
G2G2. Graminoid, prostrate dwarf-shrub, forb tundra -
G3G3. Non-tussock sedge, dwarf-shrub, moss tundra -
G4G4. Tussock-sedge, dwarf-shrub, moss tundra ||
Prostrate-shrub Tundras:
P1P1. Prostrate dwarf-shrub, herb tundra -
P2P2. Prostrate/hemiprostrate dwarf-shrub tundra ||
Erect-shrub Tundras:
S1S1. Erect dwarf-shrub tundra -
S2S2. Low-shrub tundra ||
Wetlands:
W1W1. Sedge/grass, moss wetland -
W2W2. Sedge, moss, dwarf-shrub wetland -
W3W3. Sedge, moss, low-shrub wetland
Hierarchy of Geobotanical Vegetation Map Units (Walker DA 2002)
B1. Cryptogam, herb barren
Dry to wet barren landscapes with very sparse, very low-growing plant cover. Scattered herbs, lichens, mosses, and liverworts. Subzone A and B, some C at higher elevations.
Detailed Description
Dry to wet barren desert-like landscapes mainly in Subzone A and on some coarse-grained, often calcareous sediments in subzones B and C. Sparse (2-40%) horizontal plant cover, and very low vertical structure (generally <2 cm tall) with a single layer of plants where they occur. Dry herb barrens composed of few scattered vascular plants are present over much of the landscape. Snow-flush communities are often a conspicuous component, forming dark streaks on the otherwise barren lands, composed largely of bryophytes and cryptogamic crusts. In upland areas, vascular plant cover is generally very sparse (<2%), mainly scattered individual plants often in crevices between stones or small (<50 cm diameter) cryoturbated polygons. Sedges (Cyperaceae), dwarf shrubs, and peaty mires are normally absent.
Area: 225 x 1000 km2.
Representative Syntaxa
Communities of the classes: Thlaspietea rotundifolii Br.-Bl. et al. 1947, (e.g., Papaveretum dahliani Hofm. 1968), Salicetea herbaceae Br.-Bl. et al. 1947, (e.g., Phippsietum algidae-concinnae Nordh. 1943).
Dominant Plants
The most common vascular plants are cushion forbs, graminoids, lichens, mosses, liverworts, and cyanobacteria.
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- Cushion forbs: Papaver dahlianum ssp. polare; Draba; Potentilla hyparcticaa; Saxifraga oppositifolian;
- Graminoid: Alopecurus alpinus; Deschampsia borealis/brevifolia; Poa abbreviata; Puccinellia angustata; Phippsia; Luzula nivalisa; Luzula confusaa;
- Lichen: Caloplaca; Lecanora; Ochrolechia; Pertusaria; Mycobilimbia; Collema; Thamnolia; Cetraria; Flavocetraria; Cetrariella; Stereocaulon;
- Moss: Racomitrium; Schistidium; Orthotheciumn; Ditrichumn; Distichiumn; Encalypta; Pohlia; Bryum; Polytrichum;
- Liverwort: Gymnomitrion; Cephaloziella;
- Cyanobacteria: Cyanobacteria;
a=acidic, n=non-acidic