Common (Translated Scientific) Name: Eastern North American Alpine Tundra Macrogroup

Colloquial Name: Eastern North American Alpine Tundra

Hierarchy Level:  Macrogroup

Type Concept: This dwarf-shrub-, herb-, or lichen-dominated vegetation occurs above treeline on northeastern mountains of North America, where wind, snow, and cloud-cover fog limit plant growth. Sites encompass the ancient and weathered summits and plateaus of the Canadian Shield, Canadian maritime provinces, and the northern Appalachian Mountains. Most of the cover is dwarf-shrubland or lichen-dominated; islands of taller shrubs or small graminoid meadows may occur in protected spots. The dominant plants are ericads: Vaccinium uliginosum is diagnostic and often dominant; Vaccinium vitis-idaea and, less often, Vaccinium boreale, is often common. Other alpine-restricted heaths such as Arctostaphylos alpina, Loiseleuria procumbens, Phyllodoce caerulea, and Rhododendron lapponicum are present, with composition generally varying by microsite characteristics. Other low shrubs include dwarf birches, alders and willows, such as Alnus viridis, Betula glandulosa, Betula minor, Salix argyrocarpa, Salix herbacea, and Salix uva-ursi. Diapensia lapponica is a characteristic cushion-plant, especially in highly exposed flats. Carex bigelowii is a characteristic and locally dominant sedge, Agrostis mertensii and Anthoxanthum monticola ssp. alpinum are characteristic grasses, and Juncus trifidus is a dominant rush. Forbs are comparatively scarce (except in snowbank settings), with characteristic species including Minuartia groenlandica, Prenanthes boottii, Solidago cutleri, and in a few locations, Geum peckii and Potentilla robbinsiana. In Atlantic Canada, some alpine forbland/grassland is characterized by alpine plants such as Festuca altaica, Juncus trifidus, Luzula spicata, Polygonum viviparum, and other (boreal) plants.

Diagnostic Characteristics: Alpine dwarf-shrub and herbaceous vegetation of the region''s highest elevations above treeline, with one or more of these diagnostic species: Agrostis mertensii, Arctostaphylos alpina, Betula glandulosa, Carex bigelowii, Diapensia lapponica, Geum peckii, Harrimanella hypnoides, Loiseleuria procumbens, Phyllodoce caerulea, Prenanthes boottii, Rhododendron lapponicum, Salix herbacea, Salix uva-ursi, and Solidago cutleri; Vaccinium uliginosum and Juncus trifidus are typical and often dominant.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This macrogroup differs from ~Laurentian-Acadian Acidic Scrub & Grassland Group (G788)$$ in ~Laurentian-Acadian Acidic Rocky Scrub & Grassland Macrogroup (M505)$$ in being primarily above treeline and in the presence of alpine-restricted species. In the southern part of its range, it is typically above 1220 m (4000 feet), but elevational limits change with latitude and aspect. In addition, there are many open summits in Maine and New Hampshire in the range of about 1200-1500 m (4000-5000 feet) that are above treeline where Vaccinium uliginosum and Juncus trifidus are common, but the sites may or may not have the listed "alpine obligate''" species (A. Cutko pers. comm. 2012). In Cape Breton, there are "summits" above the treeline at 350 m with alpine obligates such as Vaccinium uliginosum, Vaccinium boreale, the herbaceous species listed above, and numerous alpine lichens and bryophytes. There a few treeless peaks in New Brunswick with alpine vegetation, but fewer species represented (S. Basquill pers. comm. 2015). A recent publication by Jones and Willey (2012) provides an excellent general overview, as well as natural history descriptions of key sites throughout the range of this type, and should be consulted when future revisions are made. In particular, Jones et al. (2012) provide an overview of the vegetation. In the northern part of its range, particularly in exposed areas near the sea, including many areas of Newfoundland and coastal Labrador, as well as at high latitude in northern Quebec and Labrador, it becomes less clear what constitutes alpine landscape (Jones and Willey 2012). The alliances described for this macrogroup include everything from the typical dwarf-shrub and graminoid communities to wet snowbeds, bogs and fens. It may be appropriate to divide ~Eastern Alpine Tundra Group (G104)$$ in this macrogroup (M131) by these broad categories, but first we need to learn how distinct the bogs and fens are in the alpine zone relative to lower elevation types. ~Eastern Alpine Cliff, Scree & Rock Vegetation Group (G108)$$ in this macrogroup contains descriptions for the lichen fell-fields and cliffs.

Similar NVC Types: No Data Available

note: No Data Available