Name:
Muhlenbergia montana Herbaceous Alliance
Reference:
Western Ecology Working Group of...
Description:
This grassland alliance has been described from montane meadows in the mountains and foothills of Colorado and Utah. Sites where found are typically xeric forest openings or parks in the Ponderosa Pine zone with southern aspects on moderately steep slopes and ridgetops. Occasionally the stands occupy rolling parklands. The xeric nature of sites appears to be an important environmental factor. Soils are moderately deep Mollisols, with high coarse-fragment content, sandy loam textures, and a distinct clay horizon. Parent materials are primarily colluvium derived from granite and gneiss. Bare soil, exposed gravels, and small rocks account for as much as 50% of the ground surface area. Vegetation included in this alliance is characterized by a moderately dense herbaceous layer that is typically dominated by Muhlenbergia montana, but may be codominated by Hesperostipa comata (= Stipa comata) or by Trisetum spicatum (= Trisetum montanum) (in New Mexico). Other associated graminoids include Blepharoneuron tricholepis, Bouteloua curtipendula, Bouteloua gracilis, Carex duriuscula (= Carex eleocharis), Danthonia parryi, Elymus albicans (= Elymus lanceolatus ssp. albicans), Festuca brachyphylla, Koeleria macrantha, Muhlenbergia filiculmis, Pascopyrum smithii, Poa secunda, and Schizachyrium scoparium. The typically sparse forb layer often consists of Allium geyeri, Antennaria rosea, Arenaria fendleri, Eriogonum umbellatum, Harbouria trachypleura, Heterotheca villosa, Mertensia lanceolata, Opuntia polyacantha, and Penstemon secundiflorus. Except for the abundant dwarf-shrub Artemisia frigida, woody species are very sparse or absent. The exotic perennial grass Poa pratensis is common in some of these stands. Diagnostic of this grassland alliance is the dominance of Muhlenbergia montana in the herbaceous layer and that cover of Festuca arizonica will not be significant.
Accession Code:
VB.CC.22413.MUHLENBERGIAMON
Plot-observations of this Community Concept:
0
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