Print Report

CEGL001624 Festuca idahoensis - Pseudoroegneria spicata Grassland

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Idaho Fescue - Bluebunch Wheatgrass Grassland

Colloquial Name: Idaho Fescue - Bluebunch Wheatgrass Mixedgrass Prairie

Hierarchy Level:  Association

Type Concept: This mid-grassland is abundant in western Montana, southern Idaho and eastern Washington near the Snake River. It also occurs in northeastern California. It occurs at 900 to 2300 m (2950-7500 feet) elevation, on mostly gently rolling to flat topography, but can be found on relatively steep slopes as well. It tends to occur more on northerly exposures at the lower elevations and on southerly exposures at the higher elevations. The vegetation is characterized by the presence and dominance of Festuca idahoensis and Pseudoroegneria spicata and usually Poa secunda. Cover ranges from 5-60% for each species, and their combined cover is usually much greater than any forb component present. Commonly associated graminoid species include Carex filifolia, Danthonia intermedia, Leymus cinereus, Poa cusickii, Koeleria macrantha, Hesperostipa comata and Achnatherum occidentale. Forb species composition varies, depending on aspect and geographic distribution. Total forb cover ranges from 3 to 33%. Common forb species include Achillea millefolium, Antennaria rosea, Lupinus sericeus, Arenaria congesta, Lithophragma glabrum, and Phlox hoodii. Scattered low-stature shrubs may be present and include Chrysothamnus viscidiflorus, Ericameria nauseosa, and Artemisia tridentata.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Several authors (Daubenmire1970, Mueggler and Stewart 1980, Tisdale 1986) note that the forb component is the most variable between studies in different geographic regions in these Festuca idahoensis, Pseudoroegneria spicata, and Poa secunda-dominated grasslands. From a rangewide perspective, and in comparing these grasslands to others with different graminoid dominants and codominants, the Festuca idahoensis - Pseudoroegneria spicata types described from eastern Washington, Idaho and Montana are more similar than different.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: This grassland is characterized by the presence and dominance of Festuca idahoensis and Pseudoroegneria spicata (= Agropyron spicatum) and usually Poa secunda (= Poa sandbergii). Cover ranges from 5-60% for each species, and their combined cover is usually much greater than any forb component present. Commonly associated graminoid species include Carex filifolia, Danthonia intermedia, Leymus cinereus (= Elymus cinereus), Poa cusickii, Koeleria macrantha (= Koeleria cristata), Hesperostipa comata (= Stipa comata), and Achnatherum occidentale (= Stipa occidentalis) (some stands in southwestern Montana with significantly abundant Achnatherum occidentale are considered a Achnatherum occidentale phase of the Festuca idahoensis - Pseudoroegneria spicata type by Mueggler and Stewart (1980)). Forb species composition varies, depending on aspect and geographic distribution. Total forb cover ranges from 3 to 33% (average in eastern Washington is 14%). Common forb species include Achillea millefolium, Antennaria rosea, Lupinus sericeus, Arenaria congesta, Lithophragma glabrum (= Lithophragma bulbiferum), and Phlox hoodii. Scattered low-stature shrubs may be present and include Chrysothamnus viscidiflorus, Ericameria nauseosa (= Chrysothamnus nauseosus), and Artemisia tridentata. Invasive, non-native species will be present and even abundant in heavily disturbed stands; these include Centaurea stoebe ssp. micranthos (= Centaurea maculosa), Cirsium vulgare, Taraxacum officinale, Tragopogon dubius, Descurainia pinnata, Lactuca serriola, Bromus tectorum, and Draba verna.

Dynamics:  Heavy grazing can significantly alter the species composition of this association. Pseudoroegneria spicata will decrease in abundance, and Festuca idahoensis will follow suit if heavy use continues for many seasons. Several less-palatable forb species will either invade or increase in abundance, such as Achillea millefolium, Erigeron compositus, Gaura coccinea, and Geum triflorum. In addition, several non-native species may invade, such as Bromus tectorum, Centaurea stoebe ssp. micranthos, and Cirsium vulgare. Fire also plays an important role in maintaining this grassland. Fire can keep shrub and forb cover low, and increase the reproductive success of Pseudoroegneria spicata. Although, interestingly, one study showed no change in the abundance (canopy cover) of Pseudoroegneria spicata or Festuca idahoensis in the first few years following a burn (Daubenmire 1980).
Environmental Description:  This grassland is known from 900 to 2300 m (2950-7500 feet) elevation, on mostly gently rolling to flat topography, but can be found on relatively steep slopes as well. It tends to occur more on northerly exposures at the lower elevations and on southerly exposures at the higher elevations. Soils are primarily Mollisols, deep and dark-colored, with varying degrees of calcium carbonate buildup. pH runs from slightly acidic (6.0) to neutral or alkaline.
Geographic Range: This grassland is known from eastern Washington, southern Idaho, western Montana, Wyoming, and southern Alberta. It is likely to occur in northeastern California on the Modoc Plateau.

Nations: CA,US

States/Provinces:  AB, CA, ID, MT, WA, WY


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: G4

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.B Temperate & Boreal Grassland & Shrubland Subclass S18 2.B
Formation 2.B.2 Temperate Grassland & Shrubland Formation F012 2.B.2
Division 2.B.2.Nf Western North American Grassland & Shrubland Division D022 2.B.2.Nf
Macrogroup 2.B.2.Nf.2 Saskatoon Serviceberry / Idaho Fescue - Bluebunch Wheatgrass Grassland & Shrubland Macrogroup M048 2.B.2.Nf.2
Group 2.B.2.Nf.2.c Rough Fescue - Idaho Fescue - Bluebunch Wheatgrass Central Rocky Mountain Foothill Grassland Group G273 2.B.2.Nf.2.c
Alliance A3987 Idaho Fescue - Bluebunch Wheatgrass - Sandberg Bluegrass Dry Grassland Alliance A3987 2.B.2.Nf.2.c
Association CEGL001624 Idaho Fescue - Bluebunch Wheatgrass Grassland CEGL001624 2.B.2.Nf.2.c
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Agropyron spicatum - Festuca idahoensis Habitat Type (Daubenmire 1970)
>< Agropyron spicatum Vegetation Type (Achuff et al. 2002) [One plot included here.]
= Festuca idahoensis - Pseudoroegneria spicata (Jones and Ogle 2000)
= Festuca idahoensis / Agropyron spicatum Habitat Type (Tisdale 1986) [(p.16)]
= Festuca idahoensis / Agropyron spicatum Habitat Type (Tisdale 1979)
= Festuca idahoensis / Agropyron spicatum Habitat Type (Mueggler and Stewart 1980)
> Festuca idahoensis / Agropyron spicatum Habitat Type, Stipa occidentalis Phase (Mueggler and Stewart 1980)
= Idaho Fescue - Bluebunch Wheatgrass Herbaceous Vegetation (Festuca idahoensis - Pseudoroegneria spicata Herbaceous Vegetation) (Bell et al. 2009)
Concept Author(s): Western Ecology Group

Author of Description: G. Kittel

Acknowledgements: No Data Available

Version Date: 02-09-04
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