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A3966 Festuca idahoensis - Calamagrostis rubescens - Achnatherum nelsonii Central Rocky Mountain Montane Mesic Grassland Alliance

Type Concept Sentence: This alliance is characterized by a moderately dense to dense and diverse herbaceous layer dominated by medium-tall perennial graminoids Achnatherum nelsonii, Calamagrostis rubescens, Carex hoodii, Deschampsia cespitosa, or Festuca idahoensis with Achnatherum richardsonii, Carex filifolia, Elymus trachycaulus, Koeleria macrantha, or perennial forb Lupinus sericeus present to codominant. It is described from relatively mesic sites on montane slopes in the central Rocky Mountains of central and southern Idaho, western and south-central Montana, eastern Oregon, Washington and northwestern Wyoming.

Common (Translated Scientific) Name: Idaho Fescue - Pinegrass - Columbia Needlegrass Central Rocky Mountain Montane Mesic Grassland Alliance

Colloquial Name: Central Rocky Mountain Montane Mesic Idaho Fescue Grassland

Hierarchy Level:  Alliance

Type Concept: The vegetation of this grassland alliance is characterized by a moderately dense to dense and diverse herbaceous layer dominated by medium-tall perennial graminoids with perennial forbs. The dominant and diagnostic species are Achnatherum nelsonii, Calamagrostis rubescens, Carex hoodii, Deschampsia cespitosa, or Festuca idahoensis with Achnatherum richardsonii, Carex filifolia, Elymus trachycaulus, Koeleria macrantha, Lupinus sericeus, Pseudoroegneria spicata, or Pascopyrum smithii present to codominant. Commonly associated forbs are often relatively mesic, such as Achillea millefolium, Packera pseudaurea, Symphyotrichum foliaceum, and Zigadenus elegans. Shrubs may be present with up to 25% cover, but are not diagnostic of this alliance. Shrub species are relatively mesic with Amelanchier alnifolia, Rubus parviflorus, and Symphoricarpos albus most common. This alliance is described from montane slopes in the central Rocky Mountains of central and southern Idaho, western and south-central Montana, eastern Oregon, Washington and northwestern Wyoming. These grasslands form in openings on the slopes and benches in shrublands, woodlands and forests ranging from 1100-3322 m (3600-10,900 feet) elevation. Stands occur on mesic sites under a broad range of environmental conditions, ranging from gentle, broad, dissected plateau ridgetops to steep mountain sideslopes at 1830-2410 m (6000-7900 feet) elevation. Sites are nearly level to gently sloping with gentle topography. The soils are shallow to moderately deep and have high organic matter content. Soil texture varies from loam to sandy loam.

Diagnostic Characteristics: The relatively mesic vegetation is characterized by a moderately dense to dense and diverse herbaceous layer dominated by medium-tall perennial graminoids. The diagnostic species Achnatherum nelsonii, Calamagrostis rubescens, or Festuca idahoensis dominate with Achnatherum richardsonii, Carex filifolia, Carex hoodii, Deschampsia cespitosa, Elymus trachycaulus, Koeleria macrantha, Lupinus sericeus, Pseudoroegneria spicata, or Pascopyrum smithii codominating. Commonly associated forbs are Achillea millefolium, Arnica sororia, Antennaria parvifolia, Antennaria rosea, Arenaria congesta, Fragaria virginiana, Gaillardia aristata, Galium boreale, Gentiana affinis, Geum triflorum, Hieracium cynoglossoides, Lupinus argenteus var. laxiflorus, Packera pseudaurea, Symphyotrichum foliaceum, and Zigadenus elegans. Scattered mesic shrubs may also be present, such as Amelanchier alnifolia, Dasiphora fruticosa ssp. floribunda, Rubus parviflorus, and Symphoricarpos albus.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Stands of ~Festuca idahoensis - Elymus trachycaulus Grassland (CEGL001614)$$ reported from Colorado need additional review for inclusion in this central Rocky Mountain grassland alliance.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This alliance is characterized by moderately dense to dense cover of perennial graminoids. The graminoid stratum is dominated by both sedges and bunch grasses, ranging from 60-100% cover. The forb stratum is dominated by perennials, with 25-60% cover. Scattered shrubs may also be present.

Floristics: The vegetation is characterized by a moderately dense to dense and diverse herbaceous layer dominated by medium-tall perennial graminoids with perennial forbs. The dominant and diagnostic species are Achnatherum nelsonii, Calamagrostis rubescens, Carex hoodii, Deschampsia cespitosa, or Festuca idahoensis with Achnatherum richardsonii, Carex filifolia, Elymus trachycaulus, Koeleria macrantha, Lupinus sericeus, Pseudoroegneria spicata, or Pascopyrum smithii present to codominant. Other associated graminoids include Achnatherum occidentale (= Stipa occidentalis), Carex geyeri, and Danthonia intermedia. Commonly associated forbs are a mix of relatively mesic and dry species such as Achillea millefolium, Arnica sororia, Antennaria parvifolia, Antennaria rosea, Arenaria congesta, Fragaria virginiana, Gaillardia aristata, Galium boreale, Gentiana affinis, Geranium viscosissimum, Geum triflorum, Hieracium scouleri var. albertinum (= Hieracium albertinum), Lupinus argenteus var. laxiflorus (= Lupinus laxiflorus), Packera pseudaurea (= Senecio pseudaureus), Symphyotrichum foliaceum (= Aster foliaceus), and Zigadenus elegans. Shrubs may be present with up to 25% cover when perennial graminoid cover is high (>50% cover), but are not diagnostic of this alliance. Shrub species tend to be relatively mesic; Amelanchier alnifolia, Dasiphora fruticosa ssp. floribunda, Rubus parviflorus, and Symphoricarpos albus are the most common. Artemisia tridentata, Mahonia repens, Rosa woodsii, and Vaccinium cespitosum may also be present in low amounts. Tree saplings may also be present with significant cover.

Dynamics:  No Data Available
Environmental Description:  This alliance is described from relatively mesic sites on montane slopes in the central Rocky Mountains of central and southern Idaho, western and south-central Montana, eastern Oregon, Washington and northwestern Wyoming. These grasslands form in openings on mesic slopes and benches in shrublands, woodlands and forests ranging from 1100-3322 m (3600-10,900 feet) elevation. Stands occur on mesic sites under a broad range of environmental conditions, ranging from gentle, broad, dissected plateau ridgetops to steep mountain sideslopes at 1830-2410 m (6000-7900 feet) elevation. Sites are nearly level to gently sloping and include drier sites in extensive moist meadows. The soils are shallow to deep and have high organic matter content. Soils are typically medium-textured loams to sandy loams from a variety of parent materials.
Geographic Range: This alliance is described from montane slopes in the central Rocky Mountains in Waterton Lakes National Park, Alberta, and on the west side of Glacier National Park, Montana, in the mountains of southwestern Montana and northern Wyoming on both sides of the Continental Divide, in the Blue Mountains of eastern Oregon and Washington, and Idaho on high-elevation ridges of the Wallowa and Seven Devil mountains.

Nations: CA,US

States/Provinces:  AB, CO, ID, MT, NV, OR, UT, WA, WY


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: GNR

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.a Downy Ryegrass - Idaho Fescue - Spike Fescue Grassland Group G267 2.B.2.Nf.2.a
Alliance A3966 Idaho Fescue - Pinegrass - Columbia Needlegrass Central Rocky Mountain Montane Mesic Grassland Alliance A3966 2.B.2.Nf.2.a
Association CEGL001595 Hood''s Sedge - Idaho Fescue Grassland CEGL001595 2.B.2.Nf.2.a
Association CEGL001609 Idaho Fescue - Hood''s Sedge Grassland CEGL001609 2.B.2.Nf.2.a
Association CEGL001614 Idaho Fescue - Slender Wheatgrass Grassland CEGL001614 2.B.2.Nf.2.a
Association CEGL001625 Idaho Fescue - Richardson''s Needlegrass Grassland CEGL001625 2.B.2.Nf.2.a
Association CEGL001707 Columbia Needlegrass - Prairie Junegrass Grassland CEGL001707 2.B.2.Nf.2.a
Association CEGL001898 Idaho Fescue - Threadleaf Sedge Grassland CEGL001898 2.B.2.Nf.2.a
Association CEGL001900 Idaho Fescue - Tufted Hairgrass Grassland CEGL001900 2.B.2.Nf.2.a
Association CEGL005469 Columbia Needlegrass - Silvery Lupine Grassland CEGL005469 2.B.2.Nf.2.a
Association CEGL005860 Columbia Needlegrass - Silky Lupine Grassland CEGL005860 2.B.2.Nf.2.a
Association CEGL005862 Pinegrass Grassland CEGL005862 2.B.2.Nf.2.a
Concept Lineage: This new alliance is composed of associations from Old Alliance V.A.5.N.c. Calamagrostis rubescens Herbaceous Alliance (A.2637), Old Alliance V.A.5.N.d. Achnatherum nelsonii Herbaceous Alliance (A.1271), Old Alliance V.A.5.N.d. Carex hoodii Herbaceous Alliance (A.1253), Old Alliance V.A.5.N.d. Festuca idahoensis Herbaceous Alliance (A.1251), and Alliance V.A.5.N.j. Deschampsia caespitosa Temporarily Flooded Herbaceous Alliance (A.1355).

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: No Data Available
Concept Author(s): K.A. Schulz, in Faber-Langendoen et al. (2013)

Author of Description: K.A. Schulz

Acknowledgements: We have incorporated significant descriptive information previously compiled by M.S. Reid for group description.

Version Date: 03-14-14
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