Common (Translated Scientific) Name: Downy Ryegrass - Idaho Fescue - Spike Fescue Grassland Group

Colloquial Name: Central Rocky Mountain Montane Grassland

Hierarchy Level:  Group

Type Concept: This is an upper montane to subalpine grassland group is dominated by perennial grasses and forbs on relatively dry sites in the northern Rocky Mountains and Cascades, but is more extensive in the Rocky Mountains cordillera, from the Canadian Rockies south into western Montana, northern Wyoming, eastern Oregon, eastern Washington, and Idaho. The herbaceous layer is frequently composed of Achnatherum nelsonii, Calamagrostis rubescens, Festuca idahoensis, and Leucopoa kingii with many other perennial graminoid species present to codominant, such as Achnatherum occidentale, Achnatherum richardsonii, Danthonia intermedia, Deschampsia cespitosa, Elymus trachycaulus, Koeleria macrantha, Leymus innovatus, Phleum alpinum, Poa fendleriana, Trisetum spicatum, and a variety of Carices, such as Carex filifolia, Carex hoodii, Carex elynoides, Carex obtusata, and Carex scirpoidea. Important forbs include Chamerion angustifolium, Eriogonum caespitosum, Fragaria virginiana, Lupinus argenteus var. laxiflorus, Lupinus sericeus, Oxytropis campestris, Phlox pulvinata, Potentilla diversifolia, and Potentilla flabellifolia. The upper montane to subalpine dry grassland stands range from small meadows to large open parks surrounded by conifer trees but lack tree cover within them. In relatively mesic areas such as the northern Rocky Mountains and Cascades, it is found on drier sites, particularly south-facing slopes or ridgetops. In general, soil textures are much finer, and soils are often deeper under grasslands than in the neighboring forests. Although these grasslands are composed primarily of tussock-forming species, they do exhibit a dense sod that makes root penetration difficult for tree species. Disturbance such as fire also plays a role in maintaining these open grassy areas. This group is similar to ~Central Rocky Mountain Lower Montane, Foothill & Valley Grassland Group (G273)$$ but is found at higher elevations and is more often composed of species of Festuca, Achnatherum, and/or Hesperostipa with additional floristic components of more subalpine taxa. It is also similar to ~Rocky Mountain-North Pacific Subalpine-Montane Mesic Grassland & Meadow Group (G271)$$, differing by occurring in drier settings and being predominantly grasslands rather than forby and grassy mesic meadows. Occurrences of this group are often more forb-rich than ~Southern Rocky Mountain Montane-Subalpine Grassland Group (G268)$$, which tends to be drier.

Diagnostic Characteristics: This meadow group is dominated by graminoids, typically forming 70 to 80% cover. Bunchgrasses are the major lifeform, and the important taxa include Leymus innovatus, Koeleria macrantha, Festuca idahoensis, Achnatherum occidentale, Achnatherum richardsonii, Elymus trachycaulus, and a variety of sedges such as Carex hoodii, Carex obtusata, and Carex scirpoidea.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: For now, this group is kept as a separate unit, but it is possible it should be merged with ~Rocky Mountain-North Pacific Subalpine-Montane Mesic Grassland & Meadow Group (G271)$$. Another possibility is to consider this "grassland" group to contain what people refer to as "mesic grassy meadows," and the mesic herbaceous meadow group to contain predominantly forb meadows and tall forblands which in many cases are more seasonally wet than mesic. In addition, the Rockies and Cascades support a number of forb types found on talus and rocky scree slopes, which are not sparsely vegetated, and which often have little to no grass component, though Carices may be abundant. These types often have heavy snow loading in winter, or are adjacent to snow fields, and sub-surface moisture below the rocks/scree is significant throughout the growing season. These forb types are poorly documented, and their group placement presently is in ~Rocky Mountain-North Pacific Subalpine-Montane Mesic Grassland & Meadow Group (G271)$$.

Similar NVC Types: No Data Available

note: No Data Available