Common (Translated Scientific) Name: American Dunegrass - Seaside Sandplant - Nootka Lupine Coastal Shore Macrogroup

Colloquial Name: North American Arctic Coastal Shore

Hierarchy Level:  Macrogroup

Type Concept: This type occurs along the North American Arctic coastline and consists of stabilized coastal beaches and beach dunes. It also occurs on Arctic coastline sea cliffs, rocky headlands, and cobble beaches. Patch size is small to moderate and often linear. Two different physiognomic structures are found in the group: grasslands and dwarf-shrublands, as well as areas of bare sand or cobbles. Vegetation typically includes herbaceous species with varying degrees of tolerance for salt spray and wind abrasion. Salt-tolerant forb communities occur just above mean high tide and are dominated or codominated by Cochlearia groenlandica, Achillea millefolium var. borealis, Honckenya peploides, and/or Mertensia maritima. As dune height and distance from the ocean increase, sites are dominated by Leymus mollis communities that may include near-monocultures of Leymus mollis to more species-rich associations including Leymus mollis, Lathyrus japonicus var. maritimus, and Poa eminens. Older dunes support dwarf-shrubs (primarily Empetrum nigrum) mixed with herbaceous species which often grow in narrow stringers on the older beach ridges behind the Leymus mollis zone. On rocky cliff and cobble shores, a variety of species may occur depending on the level of salt exposure, steepness, aspect, and available microsites. Shrubs such as Alnus viridis ssp. sinuata or Rubus spectabilis may be present but usually account for less than 5% of the total vascular plant cover. Herbaceous cover is diverse and may include many of the following species: Aruncus dioicus var. acuminatus, Campanula spp., Carex macrochaeta, Chamerion latifolium, Deschampsia spp., Heuchera glabra, Lupinus nootkatensis, Phegopteris connectilis, Potentilla villosa, Prenanthes alata, and Rhodiola rosea. Picea sitchensis may also occupy these rocky headlands, and is characterized by somewhat stunted growth, usually with branches from top to bottom of bole. Epiphytic lichens are abundant in this macrogroup. Beaches are dry to mesic and typically sandy. Cobble beaches are associated with cliff and bluff systems or coarse-textured glacial deposits (i.e., coastal moraines). Beaches are often steep and feature distinct storm berms. These are typically high-energy environments exposed to wave action, wind, salt spray and storm swell. Cobble beaches may have a mixture of silts and sands below the surface (particularly in outwash plains), but the fine material is buried and not subjected to wind and water transport. Forbs, grasses, shrubs, and stunted trees establish on ledges and in cracks.

Diagnostic Characteristics: This type is characterized by grasslands and dwarf-shrublands which occupy beaches and dunes. Leymus mollis is the most consistent species, but salt-tolerant forbs are also present. Diagnostic species of sea cliffs, rocky headlands, and cobble beaches of the Arctic region needs further review.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Storm surge coastal vegetation may require inclusion in this type or perhaps a new type with salt spray influence. There are no associations currently described for coastal cliff vegetation. Type description is largely based on information from Alaska, and rangewide input is needed.

Similar NVC Types: No Data Available

note: No Data Available