Name:
Carex scirpoidea - Zigadenus elegans Herbaceous Vegetation
Reference:
Western Ecology Working Group of...
Description:
This is a small-patch herbaceous community found in Glacier National Park, Montana. It is associated with seep conditions providing a mesic to hygric moisture regime. Possibly the strongest determinant of this community is a strongly bimodal moisture regime; saturated and even having overland flow in spring and early summer and by mid to late summer subsurface flow ceases and soils dry rapidly due to warm site exposures. Within-type vegetation differences are explained by differences in water regime (considerable variation in when sites become dry, if ever) and amount of exposed rock. Plant cover is high (90+%) where continuous soils have developed but can be as low as 10% where rock cover exceeds 90%. The documented elevation range is from 1640 to 2190 m (5380-7185 feet). It is found primarily on west- to southwest-facing, moderate to steep slopes, mostly having greater than 45% inclination. This community often occurs in terrain with irregular relief owing to rock outcrops, stabilized fell-fields or talus with appreciable soil, or as a broad zone paralleling rivulets and the most incipient of first-order streams. Microsites of relatively flat outcrops of layered sedimentary rock accumulates organic humus with a high water-retention capacity providing in the aggregate an extensive substrate for this community.The vascular plant cover is highly variable (8% to 98%) in this type, and more or less inversely proportional to rock exposure in the drier expressions of the type and on moister sites in inverse proportion to the bryophyte/lichen cover. Dwarf-shrubs are scattered, comprising not much more than 5% cover; the most constant being Dasiphora fruticosa ssp. floribunda and Arctostaphylos uva-ursi. On the more lush sites, Carex scirpoidea, the dominant, highly constant and diagnostic sedge, can approach a sward-like aspect, but on the rockier sites its cover may scarcely exceed a few percent. Other graminoids of high constancy but generally of low cover include Danthonia intermedia, Festuca idahoensis, Festuca campestris (= Festuca scabrella), and Poa alpina. Alternatively, Carex podocarpa, Carex spectabilis, and Deschampsia caespitosa are present in the moister sites. Though generally typifying moist to hygric sites, this type can range to relatively wet environments as indicated by the presence of Allium schoenoprasum, Triantha glutinosa (= Tofieldia glutinosa), Packera streptanthifolia (= Senecio cymbalarioides), Dodecatheon pulchellum, Parnassia fimbriata, Symphyotrichum foliaceum (= Aster foliaceus), and Suksdorfia ranunculifolia. A number of other mesic, high constancy forbs occur with low cover, including Zigadenus elegans. Forb cover tends to occur in patches and overall it seldom exceeds 30% cover, with individual species very seldom having more than 10% cover.
Accession Code:
VB.CC.27456.CAREXSCIRPOIDEA
Plot-observations of this Community Concept:
0
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