Name:
Pascopyrum smithii - Hesperostipa comata - Schizachyrium scoparium Mixedgrass Prairie Group
Reference:
NatureServe Biotics 2019
Description:
This mixedgrass group is widespread from northern Nebraska into southern Canada and westward to the Rocky Mountain Front Range in Montana and Wyoming, on both glaciated and non-glaciated substrates. It also extends south along the Front Range to northeastern New Mexico and western Oklahoma. The vegetation is dominated by moderate to moderately dense medium-tall grasses or sometimes, in the western Great Plains and Sandhills of Nebraska, a mix of tall and medium-tall grasses. Shrubs are usually scattered or absent but can form dense, local patches, particularly in swales or low areas. Dominant species include <i>Pascopyrum smithii, Schizachyrium scoparium, Carex inops ssp. heliophila</i>, and <i>Carex filifolia</i>. In Montana, this includes <i>Festuca idahoensis</i>. Sites with a strong component of <i>Nassella viridula</i> indicate a more favorable moisture balance and perhaps a favorable grazing regime as well because this is one of the most palatable of the midgrasses. <i>Calamovilfa longifolia</i> is often found with high cover values on sandier soils, and <i>Koeleria macrantha</i> cover increases on degraded sites. Common or dominant tallgrasses in the western Great Plains are <i>Andropogon gerardii, Panicum virgatum</i>, and <i>Sorghastrum nutans</i>. Other common species include <i>Bouteloua curtipendula, Bouteloua gracilis, Hesperostipa curtiseta, Hesperostipa neomexicana, Muhlenbergia montana, Pseudoroegneria spicata, Sorghastrum nutans</i>, and <i>Sporobolus cryptandrus</i>. Common woody species include <i>Amelanchier alnifolia, Artemisia cana, Dasiphora fruticosa ssp. floribunda, Juniperus horizontalis, Prunus virginiana, Rhus trilobata</i>, and <i>Symphoricarpos occidentalis</i>. Some examples may range into more of a shrub-steppe. Fire and grazing constitute the primary dynamics affecting this group. Drought can also impact it, in general favoring the shortgrass component at the expense of the midgrasses. With intensive grazing, cool-season exotics such as <i>Poa pratensis, Bromus inermis</i>, and <i>Bromus arvensis</i> can increase in dominance. Shrub species such as <i>Juniperus virginiana</i> can also increase in dominance with fire suppression. Conversion to agriculture likewise has decreased the range of this group. This group occurs on a wide variety of landforms (e.g., mesatops, stream terraces) and in proximity to a diversity of other groups. Soils range from fine-textured loams to sandy or gravelly soils.
Accession Code:
urn:lsid:vegbank.org:commConcept:39965-{43FCA28D-8602-4B48-BB76-BD58C8859DCF}
Plot-observations of this Community Concept:
0
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