Name:
Muhlenbergia filiculmis Herbaceous Alliance
Reference:
Western Ecology Working Group of...
Description:
This alliance includes grasslands that occur at moderately high elevations (2500-2900 m) in broad, flat valley floors or on mesa tops in the central Colorado Rocky Mountains. The region has a semi-arid, continental climate. Average annual precipitation is low, <25 cm, with a summer peak in July and August. January is the coldest and driest month, and April is the month of greatest snow accumulation. The region is often subjected to strong northerly and westerly winds that can remove snow cover and subject plants to severe desiccation. Sites are level to moderately steep (to 10%) with south aspects, but are usually more mesic than the surrounding uplands. Rocks and boulders are common especially on the steeper slopes. Soils are generally dry, well-drained, shallow and coarse-textured. Parent materials include andesite and tuff. Stands described had 30-40% bare ground, 10-25% rock and 40-50% litter on the ground surface. Stands included in this montane grassland alliance have moderate canopy cover dominated by the medium-tall perennial sod grass Muhlenbergia filiculmis and the short sod grass Bouteloua gracilis. Other associated graminoids include perennial bunch grasses like Festuca arizonica, Koeleria macrantha, Muhlenbergia montana, Elymus elymoides, and the sedge Carex obtusata. The usually sparse forb cover may include species such as Hymenoxys richardsonii, Eriogonum umbellatum, Arenaria fendleri, Penstemon secundiflorus, and Castilleja integra. A sparse dwarf-shrub layer is often present, composed primarily of Artemisia frigida, Chrysothamnus spp. and Gutierrezia sarothrae. Lichens are typically relatively common. Total mean canopy cover, graminoid cover, forb cover, dwarf-shrub cover, and lichen cover were 31%, 20-23%, 4-7%, 4%, and 9-12%, respectively. These grasslands are often surrounded by montane and subalpine forest, or steep, dry grassy slopes dominated by Festuca arizonica.
Accession Code:
VB.CC.27411.MUHLENBERGIAFIL
Plot-observations of this Community Concept:
0
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