Northeastern Subalpine Woodland and Stunted Tree Heath

This ecological system encompasses vegetation of varying physiognomy at upper elevations, near and slightly above treeline, in the northeastern U.S. and adjacent Canada. It may be a zone between montane spruce-fir forest and alpine systems or may cover the ridgelines and summits of lower mountains. In the Appalachians it occurs mostly above 915 m (3000 feet) elevation but can be at much lower elevations near the Atlantic Coast. Trees become progressively stunted as exposure increases, with Picea rubens being replaced by Picea mariana in a stunted form. Vegetation structure ranges from woodland to shrubland to sparsely vegetated dwarf-shrubs and herbs. Woodlands may be locally extensive, and patches of open rock support areas of shrub, dwarf-shrub or sparse vegetation. In the subalpine zone, shrublands may be extensive on the upper slopes, forming krummholz or, in somewhat more protected spots, deciduous shrub thickets. Ericads, including Kalmia angustifolia, Ledum groenlandicum, and Vaccinium uliginosum, are the most characteristic shrubs; Empetrum nigrum and Empetrum eamesii ssp. atropurpureum (= Empetrum atropurpureum) are indicative of the subalpine zone. Vaccinium boreale occurs rarely but is diagnostic where it is present. Subalpine fens are included here: these are heath-dominated and graminoid-dominated fens, often occurring in a mosaic surrounded by other subalpine vegetation. They are on gentle slopes (usually about 10%), usually at 732 to 915 m (2400-3000 feet) elevation. Calamagrostis pickeringii is dominant and characteristic in the graminoid fens, with northern sedges such as Carex michauxiana, Carex wiegandii, Carex exilis, etc. The montane heath fens contain Alnus viridis ssp. crispa (= Alnus crispa), Ilex mucronata (= Nemopanthus mucronatus), and ericads. Peat accumulation is in the range of 10-50 cm. Occurrences are usually about 5 acres in size but range up to about 20 acres.

This system is found on the higher summits of the northern Appalachian mountains, from northern New England and the Adirondacks into the Canadian Gaspé, extending south in scattered locations into southern New England.