Print Report

A4339 Arctic Dwarf Birch Low Shrub Tundra Alliance

Type Concept Sentence: This shrub tundra alliance is found on mesic to moist sites throughout the low arctic region of Alaska. Vegetation is dominated Betula nana and other low ericaceous shrubs, including Ledum palustre ssp. decumbens and Vaccinium uliginosum.

Common (Translated Scientific) Name: Arctic Dwarf Birch Low Shrub Tundra Alliance

Colloquial Name: Arctic Dwarf Birch Low Shrub Tundra

Hierarchy Level:  Alliance

Type Concept: This alliance is dominated by Betula nana and is commonly found throughout the low arctic region on mesic to moist sideslopes and ridges in the Brooks Range foothills and on high-centered polygonal tundra of the Arctic Coastal Plain. Vegetation is characterized by low and prostrate shrubs, including Betula nana, Ledum palustre ssp. decumbens, Vaccinium uliginosum, and Salix pulchra. Dwarf-shrubs such as Vaccinium vitis-idaea and Loiseleuria procumbens may be common. Herbaceous species are sparse, but certain graminoids have high constancy, including Anthoxanthum monticola ssp. alpinum in montane sites and sedges in moist tundra on the coastal plain. Fruticose lichens, particularly Cladonia rangiferina and other Cladonia species, are often abundant in the ground layer. Common mosses include Hylocomium splendens and Sphagnum, Aulacomnium, and Polytrichum species. Patch size is small to matrix-forming.

Diagnostic Characteristics: This alliance is defined by mesic to moist sites dominated by Betula nana (25-90% cover) in a low or prostrate growth form. Additional differential species for this alliance include Ledum palustre ssp. decumbens, Vaccinium uliginosum, and Cladonia species.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Former North American Arctic & Subarctic Low Shrub Tundra Group (G369) has been split into ~North American Arctic & Subarctic Low Willow Tundra Group (G827)$$ and ~North American Arctic & Subarctic Dwarf Birch Tundra Group (G828)$$. The latter group is further refined by specifying dominance by Betula nana as a diagnostic characteristic.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This alliance is represented by broad-leaved deciduous low or prostrate shrubs.

Floristics: This tundra alliance is dominated by Betula nana with at least 25% cover and is commonly found throughout the low arctic region on mesic to moist sideslopes and ridges in the Brooks Range foothills and on high-centered polygonal tundra of the Arctic Coastal Plain. Vegetation is characterized by low and prostrate shrubs, including Betula nana, Ledum palustre ssp. decumbens, Vaccinium uliginosum, and Salix pulchra. Dwarf-shrubs such as Vaccinium vitis-idaea and Loiseleuria procumbens may be common. Herbaceous species are sparse, but certain graminoids have high constancy, including Anthoxanthum monticola ssp. alpinum in montane sites and sedges in moist tundra on the coastal plain. Fruticose lichens, particularly Cladonia rangiferina (= Cladina rangiferina) and other Cladonia species, are often abundant in the ground layer. Common mosses include Hylocomium splendens and Sphagnum, Aulacomnium, and Polytrichum species. Patch size is small to matrix-forming.

Dynamics:  This alliance appears to be fairly stable. Change in site hydrology is the most likely driver of successional change with drying promoting the development of dwarf-shrub types and wetting promoting the development of shrub bogs.
Environmental Description:  This shrub tundra alliance is common throughout the low arctic bioclimatic zones on mesic mountain slopes, hillslopes, high-centered polygons, drained lake basins, and terraces. The vegetation can form complex small-scale patterning in response to a variety of environmental gradients (Walker et al. 2011). Patch size is small to matrix-forming. Permafrost is typically present.
Geographic Range: This alliance occurs throughout the low arctic bioclimatic zones (E and D); Betula nana does not occur in the high arctic.

Nations: CA,GL,IS,NO,RU,US

States/Provinces:  AK, LB, MB, NT, NU, QC, YT


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 4 Polar & High Montane Scrub, Grassland & Barrens Class C04 4
Subclass 4.B Temperate to Polar Alpine & Tundra Vegetation Subclass S12 4.B
Formation 4.B.2 Polar Tundra & Barrens Formation F031 4.B.2
Division 4.B.2.Xa Arctic Tundra & Barrens Division D044 4.B.2.Xa
Macrogroup 4.B.2.Xa.2 Feltleaf Willow - Eight-petal Mountain-avens - Tussock Cottongrass Tundra Macrogroup M173 4.B.2.Xa.2
Group 4.B.2.Xa.2.a Arctic Low Shrub Tundra Group G897 4.B.2.Xa.2.a
Alliance A4339 Arctic Dwarf Birch Low Shrub Tundra Alliance A4339 4.B.2.Xa.2.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: > II.C.1.a - Shrub birch (closed) low (Viereck et al. 1992)
> II.C.1.c - Shrub birch-willow (closed) low (Viereck et al. 1992)
> II.C.2.c - Mesic shrub birch-ericaceous shrub (open) low (Viereck et al. 1992)
> II.C.2.f - Shrub birch-willow (open) low (Viereck et al. 1992)
< S2. Low-shrub tundra (Raynolds et al. 2006a) [These types also include G368 - tall shrubs, as they occur in narrow bands along streams or in alpine treeline that are too small to map at this scale. Additional references for this type are found in this publication.]
> S2. Low-shrub tundra (CAVM Team 2003)
Concept Author(s): Western Ecology Group and Alaska Natural Heritage Program, in Faber-Langendoen et al. (2016)

Author of Description: T. Boucher, K. Boggs and M. Hall

Acknowledgements: No Data Available

Version Date: 01-19-16
  • Boggs, K. W., S. C. Klein, J. E. Grunblatt, and B. Koltun. 2003. Landcover classes, ecoregions and plant associations of Katmai National Park and Preserve. Natural Resource Technical Report NPS/KATM/NRTR--2003/001. National Park Service, Fort Collins, CO. 274 pp.
  • Boggs, Keith. Personal communication. Ecologist, Alaska Natural Heritage Program, Environment and Natural Resources Institute, University of Alaska, Anchorage.
  • CAVM Team. 2003. Circumpolar arctic vegetation map (Scale 1:7 500 000). Conservation of Arctic Flora and Fauna (CAFF) Map No. 1, USDI Fish and Wildlife Service, Anchorage, AK.
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Jorgenson, J. C., P. E. Joria, T. R. McCabe, B. E. Reitz, M. K. Raynolds, M. Emers, and M. A. Willms. 1994. User''s guide for the land-cover map of the coastal plain of the Arctic National Wildlife Refuge. USDI Fish and Wildlife Service, Region 7, Anchorage, AK. 44 pp.
  • Nowacki, G., P. Spencer, M. Fleming, T. Brock, and T. Jorgenson. 2001a. Unified ecoregions of Alaska. Open file-report 02-297. USDI U.S. Geological Survey. 2 pp. plus map.
  • Raynolds, M. K., D. A. Walker, and H. A. Maier. 2006a. Alaska Arctic Tundra Vegetation Map. Scale 1:4,000,000. Conservation of Arctic Flora and Fauna Map No. 2. U.S. Fish & Wildlife Service, Anchorage, AK.
  • Ritchie, R., J. Curatolo, and A. Batten. 1981. Knik Arm wetland study. Final report. Alaska Biological Research, Fairbanks. 195 pp.
  • Viereck, L. A., C. T. Dyrness, A. R. Batten, and K. J. Wenzlick. 1992. The Alaska vegetation classification. General Technical Report PNW-GTR286. USDA Forest Service, Pacific Northwest Research Station, Portland, OR. 278 pp.
  • Walker, D. A., P. Kuss, H. E. Epstein, An. N. Kade, C. M. Vonlanteh, M. K. Raynolds, and F. J. A. Daniëls. 2011. Vegetation of zonal patterned-ground ecosystem along the North America Arctic bioclimate gradient. Applied Vegetation Science 14:440-463.