Name:
A.1255
Reference:
EcoArt 2002
Description:
This grassland alliance is found in the northwestern Great Plains, in the Northern Rockies on both sides of the Continental Divide, and west into eastern Washington and Oregon. Elevations range from 500-2100 m, but are found only below 1500 m in Canada. Stands occur in glaciated landscapes, on prairies, foothills and mountain slopes. Sites are nearly level to steep slopes on all aspects. Sites range from mesic to relatively xeric. In the northern extent it is restricted to warmer west- and southwest-facing slopes. Soils are derived from a variety of parent materials and are loamy and moderately deep, with neutral pH. These grasslands typically occur in a mosaic with montane forests dominated by ~Pinus contorta$. Vegetation included in this alliance is characterized by the dominance of ~Festuca campestris$. Codominants may include ~Pseudoroegneria spicata$ or ~Festuca idahoensis$. The forb layer is sparse to moderately dense, often with relatively high species diversity. Scattered woody species may also be present. Annuals are typically sparse. Overall species composition varies geographically with stands east of the Continental Divide resembling Northern Mixed Prairie and stands west of the Divide floristically related to the Intermountain Basin. The east side stands may lack ~Festuca idahoensis$, but often include ~Bouteloua gracilis, Muhlenbergia cuspidata, Hesperostipa comata (= Stipa comata), Artemisia ludoviciana, Heterotheca villosa, Liatris punctata, Lupinus sericeus$, and the dwarf-shrubs ~Artemisia frigida$ and ~Gutierrezia sarothrae$. West of the Divide ~Balsamorhiza sagittata, Besseya wyomingensis, Castilleja lutescens$, and ~Lomatium triternatum$ are more common. Other common species include ~Antennaria rosea, Carex filifolia, Carex obtusata, Geranium viscosissimum, Koeleria macrantha, Poa secunda, Potentilla gracilis, Achnatherum occidentale (= Stipa occidentalis), Achnatherum richardsonii (= Stipa richardsonii)$, and the shrub ~Rosa arkansana$. Diagnostic of this grassland alliance is the dominance of ~Festuca campestris$.
Accession Code:
VB.CC.1022.A1255
Plot-observations of this Community Concept:
0
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