Print Report
M175 Arctic Scree, Rock & Cliff Barrens Macrogroup
Type Concept Sentence: This macrogroup consists of sparsely vegetated talus, bedrock, cliffs, rock outcrops, and rocky floodplains in the Arctic regions of North America, with <10% vascular cover and variable cover of mosses and lichens. Some forbs and graminoids include Draba spp., Saxifraga spp., Oxyria digyna, Festuca brachyphylla, and others.
Common (Translated Scientific) Name: Arctic Scree, Rock & Cliff Barrens Macrogroup
Colloquial Name: Arctic Scree, Rock & Cliff Barrens
Hierarchy Level: Macrogroup
Type Concept: This macrogroup occurs on talus- and bedrock-dominated sites on cliffs and rocky outcrops, and on sparsely vegetated rocky floodplains in the Arctic regions of North America. Sites are well-drained to excessively drained, rocky, and with little soil development. Sites may also occur on early-seral alpine sites near glaciers. The rocky substrate is sparsely vegetated, typically with <10% vascular cover and variable cover of mosses and lichens. Vascular species include forbs and graminoids such as Draba spp., Saxifraga spp., Oxyria digyna, Festuca brachyphylla, Carex pyrenaica ssp. micropoda, Anthoxanthum monticola ssp. alpinum, and Luzula spp. Dwarf-shrubs are uncommon. Floodplains may have seedlings of Salix spp., Populus spp., Equisetum spp., and Carex spp., but these sites are rapidly drained and not truly mesic environments, thus mesic vegetation does not persist.
Diagnostic Characteristics: Vascular cover <10%, high rocky coverage of ground surface (>90%), and Arctic climate.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This macrogroup concept is preliminary and needs further review.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: The rocky substrate is sparsely vegetated, typically with <10% vascular cover and variable cover of mosses and lichens. Vascular species include forbs and graminoids such as Draba spp., Saxifraga spp., Oxyria digyna, Festuca brachyphylla, Carex pyrenaica ssp. micropoda (= Carex micropoda), Anthoxanthum monticola ssp. alpinum (= Hierochloe alpina), and Luzula spp. Dwarf-shrubs are uncommon.
Unvegetated silt and cobble bars occur adjacent to active river channels during periods of low water and can be flooded several times during the summer. Occasional seedlings of willow or balsam popular may become established but they usually do not persist due to damage by subsequent flooding (Viereck et al. 1993).
Unvegetated silt and cobble bars occur adjacent to active river channels during periods of low water and can be flooded several times during the summer. Occasional seedlings of willow or balsam popular may become established but they usually do not persist due to damage by subsequent flooding (Viereck et al. 1993).
Dynamics: Climate change may allow for shrub expansion in these environments (Tape et al. 2006).
Environmental Description: On barren floodplains the alluvium consists of alternating layers of fine and medium sands with more coarse material with depths up to 120 cm and are described as flooded or saturated by Viereck et al. (1993). The concept for this macrogroup is the larger, deeper, and drier versions of active floodplain gravels.
Geographic Range: This macrogroup occurs in arctic areas of North America from Alaska across northern Canada and possibly Greenland.
Nations: CA,GL,IS,NO,RU,US
States/Provinces: AK, LB?, NT, NU, QC?, YT
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.860574
Confidence Level: Moderate
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.1 Arctic Scree, Rock & Cliff Barrens Macrogroup | M175 | 4.B.2.Xa.1 |
| Group | 4.B.2.Xa.1.b Arctic Gravel Floodplain Vegetation Group | G616 | 4.B.2.Xa.1.b |
| Group | 4.B.2.Xa.1.c Arctic Lichen Barrens Group | G868 | 4.B.2.Xa.1.c |
| Group | 4.B.2.Xa.1.d Arctic Open Scree, Rock & Cliff Barrens Group | G869 | 4.B.2.Xa.1.d |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- Tape, K. E. N., M. Sturm, and C. Racine. 2006. The evidence for shrub expansion in northern Alaska and the Pan-Arctic. Global Change Biology 12(4):686-702. [doi:10.1111/j.1365-2486.2006.01128.x]
- Viereck, L. A., C. T. Dyrness, and M.J. Foote. 1993. An overview of the vegetation and soils of the floodplain ecosystems of the Tanana River, interior Alaska. Canadian Journal of Forestry Research 23:889-989.