Glaciere talus, felsenmeer, is a rare open primary community that consists of steep slopes of quartzite or other metamorphic rock boulders (0.25-1 meter in diameter) formed by periglacial frost and ice-wedging, and is characterize by cool, moist air drainage at or near the base. The vegetation is fairly sparse but may be structurally variable. Lichens (Lasallia spp.) are the dominant cover on the boulders. Scattered soil pockets may occur and support scattered white and red pines (Pinus strobus and P. resinosa) often in association with mossy beds of common polypody (Polypodium virginianum) or marginal shield fern (Dryopteris marginalis). The slope base in the zone of cool air drainage is typically shrub dominated and may include a number of species somewhat disjunct from their more northern ranges, such as squash-berry (Viburnum edule) and Canada gooseberry (Ribes oxyacanthoides). Other frequently occurring shrub or small tree species are Labrador-tea (Rhododendron groenlandicum), mountain maple (Acer spicatum), mountain ash (Sorbus spp.), and red-berried elder (Sambucus pubens). The vine, purple clematis (Clematis occidentalis) and tree, balsam fir (Abies balsamea) may also be present. This community type has been incompletely surveyed and occurrences should be carefully examined for rare bryophytes, lichens, and terrestrial snails.
