Name:
Trollius laxus - Parnassia fimbriata Herbaceous Vegetation
Reference:
Western Ecology Working Group of...
Description:
This community has been documented from throughout the subalpine and alpine of Glacier National Park, Montana. This is a palustrine wetland type occurring at upper subalpine to lower alpine environments, from 1960 to 2320 m (6430-7610 feet). It is found as a mostly linear, small-patch type bordering first- and second-order steams and associated with seeps and subirrigated positions. Often associated with glacial cirque basins, most of the sites are very low-gradient terraces and benchlands, collecting positions, often with a concave surface. High moisture status is the primary driving variable overwhelming any differences in slope, exposure or parent material. Sites are developed on limestones, argillites and diorite. The upper soil horizons are black, very high in organic content and, if sufficiently deep, qualify the sites as peatlands; bank overflow and slopewash are responsible for a considerable amount of silt accumulating in the peat mat. The vascular layer is both lush (exceeding 80% cover in 90% of plots) and diverse. This community is characterized by an assemblage of low-growing forbs; however, Senecio triangularis is consistently present, with cover not much exceeding 5%. Characteristic low-stature forbs include Trollius laxus, Triantha glutinosa (= Tofieldia glutinosa), Parnassia fimbriata, Hypericum scouleri (= Hypericum formosum), Veronica wormskjoldii, and Packera streptanthifolia (= Senecio cymbalarioides), any one of which may express dominance. Allium schoenoprasum, Arnica X diversifolia, Arnica mollis, and Symphyotrichum foliaceum (= Aster foliaceus) are also consistently present. Carex podocarpa is the only high-constancy graminoid also having appreciable cover (often in excess of 10%); Carex nigricans, Juncus drummondii, and Poa alpina are present in 50% or more of the plots. Carex lenticularis is exclusive to plots with well-developed, though not necessarily deep, peaty soils. Moss cover is in excess of 40% and mostly greater than 80% with Philonotis fontana, Bryum spp., Brachythecium spp., and Campylium stellatum comprising the majority of cover. Lichens, if present, occur only in trace amounts.
Accession Code:
VB.CC.28058.TROLLIUSLAXUSPA
Plot-observations of this Community Concept:
0
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