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G864 Arctic Coastal Dune & Beach Group
Type Concept Sentence: This group represents Leymus mollis grasslands developing on sandy upper beaches and coastal dunes along the Arctic Ocean and Bering Sea coastlines.
Common (Translated Scientific) Name: Arctic Coastal Dune & Beach Group
Colloquial Name: Arctic Coastal Dune & Beach
Hierarchy Level: Group
Type Concept: This group is defined by grasslands developing on coastal beaches and dunes. Leymus mollis is the most constant and abundant species, with the salt-tolerant forbs Honckenya peploides and Lathyrus japonicus var. maritimus indicating the group. Bryophytes, lichens and woody species are generally absent. This group develops on coastal beaches above the elevation of maximum high tide as well as on dunes along mainland shores and barrier islands. Sites are not regularly inundated by tidal waters but are subject to salt spray and occasional inundation by storm surges. Soils are dry to mesic and typically sandy with small pebbles. Permafrost is present at depth along the Arctic Ocean coast but becomes discontinuous along the Bering Sea coast.
Diagnostic Characteristics: This group is defined by grasslands developing on coastal beaches and dunes. Leymus mollis is the most constant and abundant species, but the salt-tolerant forbs Honckenya peploides and Lathyrus japonicus var. maritimus indicate the group.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Inclusion of salt-killed tundra from storm surges is not recommend as, assuming storm surge disturbance is limited to the inundation and deposition of saline water and sediment, near-coast tundra is not likely to transition to a beach or dune type. It is more appropriate to describe salt-killed tundra within the various groups susceptible to storm surges such as tussock, dwarf- and low-shrub, and wet graminoid tundra.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This group is represented by sparse to closed growth of graminoid-dominated vegetation often in combination with salt-tolerant forbs.
Floristics: This group is dominated by the grass Leymus mollis and indicated by the salt-tolerant forbs Honckenya peploides and Lathyrus japonicus var. maritimus. Throughout the range of this group the grass Festuca rubra and the forb Mertensia maritima may be present. Along the Arctic Ocean coast additional species may include Festuca baffinensis and Cnidium cnidiifolium, whereas Poa eminens, Senecio pseudoarnica, Ligusticum scoticum, and Conioselinum chinense are more common components along the Bering Sea coast. With the exception of some feathermosses, bryophytes, lichens and woody species are generally absent. Along rising or otherwise prograding coastlines, a series of dune ridges and slacks may develop landward. In these systems, the moist slacks may be colonized by more species-rich associations of forbs and dwarf-shrubs such as Empetrum nigrum.
Dynamics: Sites are not regularly inundated by tidal waters but are subject to salt spray and occasional inundation by storm surges. During snow- and ice-free periods, sites are fully exposed to coastal processes, especially erosion by wind and water. This is a ruderal type held in an early-successional state by frequent disturbance. Where beaches and dunes gain protection from tidal and storm surge effects (e.g., through rise above tidal range or other progradation of the seaward margin), the type may transition to the adjacent inland vegetation type.
Environmental Description: This group develops on coastal beaches above the reach of maximum high tide as well as on dunes along mainland shores and barrier islands. Soils are dry to mesic and typically sandy with small pebbles. Permafrost is present at depth along the Arctic Ocean mainland coast and remnant barrier islands but becomes discontinuous along the Bering Sea coast and is absent from constructed barrier islands. Among the barrier islands, vegetated dunes are more common on the remnant barrier islands, which represent relict coastline, than they are on constructed types, which are highly dynamic systems representing comparatively recent depositions of sediment.
Geographic Range: This group occurs along Alaska''s Arctic Ocean and Bering Sea coastlines, from the Bristol Bay lowlands in southwestern Alaska, across the Arctic Coastal Plain and likely extending to Canada and Greenland.
Nations: CA,GL?,US
States/Provinces: AK, LB, MB, NT, NU, QC, YT
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.1041616
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.B Temperate & Boreal Grassland & Shrubland Subclass | S18 | 2.B |
| Formation | 2.B.4 Temperate to Polar Scrub & Herb Coastal Vegetation Formation | F005 | 2.B.4 |
| Division | 2.B.4.Nd Arctic Coastal Scrub & Herb Vegetation Division | D146 | 2.B.4.Nd |
| Macrogroup | 2.B.4.Nd.1 American Dunegrass - Seaside Sandplant - Nootka Lupine Coastal Shore Macrogroup | M402 | 2.B.4.Nd.1 |
| Group | 2.B.4.Nd.1.a Arctic Coastal Dune & Beach Group | G864 | 2.B.4.Nd.1.a |
| Alliance | A4296 Arctic Coastal Dune Alliance | A4296 | 2.B.4.Nd.1.a |
| Alliance | A4297 Arctic Coastal Beach Alliance | A4297 | 2.B.4.Nd.1.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > III.A.1.a - Elymus (Viereck et al. 1992)
> III.B.2.d - Halophytic herb wet meadow (Viereck et al. 1992)
> III.B.2.d - Halophytic herb wet meadow (Viereck et al. 1992)
- 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]
- Hopkins, D. M., and R. W. Hartz. 1978. Coastal morphology, coastal erosion, and barrier islands of the Beaufort Sea, Alaska. Open File Report 78-1063. U.S. Geological Survey. 54 pp.
- Morack, J. L., and J. Rogers. 1981. Seismic evidence of shallow permafrost beneath Islands in the Beaufort Sea, Alaska. Arctic 34(2):169-174.
- Short, A. D. 1979. Barrier island development along the Alaskan-Yukon coastal plains: Summary. Geological Society of America Bulletin 1(90):3-5.
- 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.