Name:
Muhlenbergia montana - Hesperostipa comata Herbaceous Vegetation
Reference:
Western Ecology Working Group of...
Description:
This association has been described from north-central and central Colorado, in the northeastern portion of the Roosevelt National Forest. The association also occurs in Rocky Mountain National Park in the Mummy Range and Florissant Fossil Beds National Monument. Sites where the association is found are typically xeric forest openings in the ponderosa pine zone, on south-facing slopes and ridgetops. Elevations range from 2286 to 2590 m (7500-8500 feet), and the slopes are moderately steep. Occasionally the association occupies rolling parklands. Strong, westerly winds probably result in removal of snow cover from the open sites and increased desiccation of plants. Soils are moderately deep Mollisols, with high coarse fragment content, sandy loam textures, and a distinct clay horizon. Parent materials are primarily colluvium of granitic and gneiss origins. Bare soil, exposed gravels, and small rocks account for as much as 30% of the ground surface area. This grassland association is strongly dominated by the perennial bunch grasses Muhlenbergia montana and Hesperostipa comata (= Stipa comata), averaging 11% and 22% cover, respectively. Several other graminoids are commonly present, including Carex duriuscula (= Carex eleocharis), Pascopyrum smithii, Koeleria macrantha, Danthonia parryi, Muhlenbergia filiculmis, and Poa secunda. Total graminoid cover averages 45%. Forb species are much less abundant, totaling <10% cover. The most important include Allium geyeri, Antennaria rosea, Arenaria fendleri, Harbouria trachypleura, Mertensia lanceolata, and Penstemon secundiflorus. Shrubs are absent or scarce, except for the suffrutescent Artemisia frigida, with 5% average cover. This association can be distinguished from Muhlenbergia montana Herbaceous Vegetation (CEGL001646) by the abundance to codominance of Hesperostipa comata.
Accession Code:
VB.CC.22412.MUHLENBERGIAMON
Plot-observations of this Community Concept:
0
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