Community Field Guide
Scientific Name:
Juncus drummondii - Antennaria lanata Herbaceous Vegetation
Common Name:
Drummond's rush - woolly pussytoes Herbaceous Vegetation
Community Description
Summary:
This alpine wetland community has been described from only the southern Madison Range in southwestern Montana (2930-3050 m elevation), where it occurs regularly as small patches (much less than one acre in extent). Stands are common in alpine valley depressions, swales and cirque basins in association with late-persisting snowbeds. This snowbed community occurs on gentle terrain (4-22% slope) with various aspects, often as a mosaic with other snowbed communities. Soils are typically shallow, well-drained and have sandy clay texture with 13% coarse fragments derived from gneiss and granite parent materials. Gravel and bare ground cover 50% of the soil surface. The vegetation layer is a mixture of graminoids (30% mean cover) and forbs (37% mean cover) with graminoids generally dominant. The major graminoids are Juncus drummondii, Poa fendleriana, and Carex paysonis. The most common forb species are Antennaria lanata, Sibbaldia procumbens, and Erigeron peregrinus. The dwarf-shrub Vaccinium scoparium and Carex paysonis were important (10% cover each) in one of the three stands sampled. Mosses and lichens had relatively low cover. Diagnostic of this relatively sparse alpine association is the codominance of Juncus drummondii and Antennaria lanata.
Environment:
Small patches (tenths of an acre at most) of Juncus drummondii / Antennaria lanata are relatively common in swales and other snow-collection microtopography sets within valleys and cirque basins between 9,600 and 10,000 feet in the Madison Range. This community is always associated with areas of late snowmelt; however, melt-off probably occurs earlier than in communities dominated by Carex nigricans. Juncus drummondii / Antennaria lanata was often part of vegetation mosaic resulting from uneven snow deposition. Commonly associated communities are moist turf, wetlands and other snowbed associations such as Carex scirpoidea / Geum rossii, Carex scopulorum / Caltha leptosepala, Carex nigricans and Phyllodoce empetriformis / Antennaria lanata.
Vegetation:
Mean graminoid cover was 30%. Dominant graminoids were Juncus drummondii, Poa fendleriana and Carex paysonis. Carex pyrenaica was locally common. Mean cover of forbs was 37% and common species included Antennaria lanata, Sibbaldia procumbens and Erigeron peregrinus. Arnica latifolia was common in one stand. The shrub, Vaccinium scoparium was also common in this same stand. Mean cover of mosses and lichens was 2%.
Range:
This community has been described from only the southern Madison Range (Beaverhead Mountains Section [Nesser et al. 1997] of Bailey's [1995] Middle Rocky Mountain Province) where it occurs regularly. Macro- and mesoclimatic factors and substrates differ in no significant way from those of surrounding ranges; the uniqueness of these communities may be attributable to historical vagaries of floristic distribution.
Global Rank: G3? State Rank: S2
Global Rank Comments:
This association is under no particular threat and the snowbed environment characterized by its presence is in no way unusual. Apparently relatively rare, this association is recorded from just the southern portion of the Madison Range of southwestern Montana (Cooper et al. 1997), but inventory of alpine areas in Montana is far from complete so this association may be represented in other ranges. Snowbed environments dominated by Juncus drummondii are described from Colorado alpine and Antennaria lanata-dominated snowbeds are documented for the North Cascades of Washington and the Canadian Rocky Mountains; the association treated here is somewhat of a floristic hybrid.
Community References
Identifier:
CEGL001904
Author:
97/10 / S. V. Cooper et al.
Citations:
Bourgeron and Engelking 1994, Cooper and Lesica 1992, Cooper et al. 1997, Cooper et al. 1999, Driscoll et al. 1984
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This information is from the:
Montana Natural Heritage Program
Montana State Library--Natural Resource Information System
1515 East Sixth Ave., Helena, MT 59620-1800
406 444-3989
mtnhp.org
mtnhp@mt.gov
