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A3987 Festuca idahoensis - Pseudoroegneria spicata - Poa secunda Dry Grassland Alliance

Type Concept Sentence: This widespread dry grassland alliance is characterized by an open to moderately dense herbaceous layer dominated by diagnostic perennial bunchgrasses Festuca idahoensis, Pseudoroegneria spicata, and/or Poa secunda and occurs in the northwestern Great Plains, central Rocky Mountains and interior Pacific Northwest.

Common (Translated Scientific) Name: Idaho Fescue - Bluebunch Wheatgrass - Sandberg Bluegrass Dry Grassland Alliance

Colloquial Name: Idaho Fescue - Bluebunch Wheatgrass - Sandberg Bluegrass Dry Grassland

Hierarchy Level:  Alliance

Type Concept: Vegetation of this dry grassland alliance is characterized by an open to moderately dense herbaceous layer dominated by diagnostic perennial bunchgrasses Festuca idahoensis, Pseudoroegneria spicata, and/or Poa secunda. Balsamorhiza sagittata, Balsamorhiza serrata, Carex filifolia, Eriogonum heracleoides, Hesperostipa comata, Hieracium cynoglossoides, or Lomatium cous may codominate the herbaceous layer. Scattered shrubs may be present, are generally low in stature (<0.5 m) and cover (<5%) and include browsed Amelanchier alnifolia, Artemisia frigida, Artemisia tridentata, Chrysothamnus viscidiflorus, Ericameria nauseosa, Gutierrezia sarothrae, Juniperus communis, and Juniperus horizontalis. Other common graminoid species include Achnatherum occidentale, Danthonia intermedia, Leymus cinereus, and Poa cusickii. Forb species are typically diverse with low cover. This widespread dry grassland alliance occurs in the northwestern Great Plains, central Rocky Mountains and interior Pacific Northwest. Stands are found on relatively dry valley bottoms, stream terraces, rolling uplands, canyon benches and slopes, hills, ridges, plateaus and buttes, badlands, foothills, expansive park meadow openings in montane forests, and glacial outwash plains. Elevation ranges from 200-2500 m on any aspect, becoming restricted to west- and southwest-facing slopes farther north. Substrates are variable and range from shallow and lithic soils with a rocky surface of gravel, cobbles or scoria, to moderately deep soils with little rock.

Diagnostic Characteristics: This alliance is characterized by an open to moderately dense herbaceous layer dominated by diagnostic perennial bunch grasses Festuca idahoensis, Pseudoroegneria spicata, and/or Poa secunda. Additional diagnostic species include Balsamorhiza sagittata, Balsamorhiza serrata, Carex filifolia, Eriogonum heracleoides, Hesperostipa comata, Hieracium cynoglossoides, or Lomatium cous, which may codominate the herbaceous layer and indicate relatively dry sites.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance includes most of the associations from former Pseudoroegneria spicata Herbaceous Alliance (A.1265), former Poa secunda Herbaceous Alliance (A.1291), and selected drier site associations from former Festuca idahoensis Herbaceous Alliance (A.1251). Some of the associations are variable or not well-defined environmentally and need further review for alliance placement.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Vegetation in this alliance is characterized by a sparse to dense cover of graminoids that is dominated by perennial bunch grasses less than 1 m tall. There is also sparse to moderate cover of perennial forbs. Occasional scattered shrubs and dwarf-shrubs may be present. Annual forbs and grasses are seasonally present.

Floristics: Vegetation is characterized by an open to moderately dense herbaceous layer dominated by diagnostic perennial bunchgrasses Festuca idahoensis, Pseudoroegneria spicata, and/or Poa secunda. Balsamorhiza sagittata, Balsamorhiza serrata, Carex filifolia, Eriogonum heracleoides, Hesperostipa comata, Hieracium cynoglossoides, or Lomatium cous may codominate the herbaceous layer. Scattered shrubs present are generally low in stature (<0.5 m) and cover (<5%) and include browsed Amelanchier alnifolia, Artemisia frigida, Artemisia tridentata, Chrysothamnus viscidiflorus, Ericameria nauseosa, Gutierrezia sarothrae, Juniperus communis, and Juniperus horizontalis. Other common graminoid species include Achnatherum occidentale (= Stipa occidentalis), Danthonia intermedia, Leymus cinereus (= Elymus cinereus), and Poa cusickii. Forb species typically present include Achillea millefolium, Antennaria rosea, Arenaria congesta, Campanula rotundifolia, Erigeron corymbosus, Eriogonum umbellatum, Frasera albicaulis, Galium boreale, Geum triflorum, Hedysarum sulphurescens, Lithophragma glabrum (= Lithophragma bulbiferum), Lomatium bicolor var. leptocarpum, Lupinus caudatus, Lupinus sericeus, Phlox hoodii, Phlox longifolia, and Trifolium macrocephalum.

Dynamics:  Fire has variable effects on Pseudoroegneria spicata. Plants usually survive burning, and growth is often stimulated, except when fire occurs in the driest month when the crowns will burn because of low moisture in the vegetation, and the meristems are damaged (Johnson and Simon 1987). Grazing impacts are concentrated on the gentler slopes accessible to livestock. Pseudoroegneria spicata shows an inconsistent reaction to grazing, increasing on some grazed sites while decreasing on others. It seems to recover more quickly from overgrazing than Festuca campestris (Mueggler and Stewart 1980). It tolerates dormant-period grazing well, but is sensitive to defoliation during the growing season. Light spring use or fall grazing can help retain plant vigor. It is particularly sensitive to defoliation in late spring (Comer et al. 1999). The exotic species Bromus tectorum occurs in many stands of the alliance and contributes significant cover on sites disturbed by livestock.
Environmental Description:  This widespread western dry grassland alliance occurs in the northwestern Great Plains, foothills and montane zones in the central Rocky Mountains from northwestern Montana, extending north into Alberta, west across the interior Pacific Northwest to the foothills of the eastern Cascades, and south to the Grand Teton Mountains of northwestern Wyoming, and ranges in northern Utah, Nevada and northeastern California. It occurs on dry sites on any aspect from 200-2500 m elevation depending on region, becoming restricted to warmer southerly and westerly aspects at higher elevations and northern latitudes. Climate is temperate and mostly continental. Mean annual precipitation ranges from 33-60 cm. Season of precipitation varies geographically. In the Columbia Basin precipitation comes mainly in the winter as snow or rain. This moisture is stored in the soil profile and utilized throughout the typically dry summers. Stands in the Rocky Mountains and northwestern Great Plains may receive up to 75% of the annual precipitation during the growing season. Stands are found on valley bottoms, stream terraces, rolling uplands, canyon benches and slopes, hills, ridges, plateaus and buttes, badlands, foothills, expansive park meadow openings in montane forests, and glacial outwash plains. Sites may be xeric or mesic, on nearly level to steep slopes. The alliance occurs on all aspects, but often on the drier southern and western slopes. Substrates are also variable and range from shallow and lithic soils with a rocky surface of gravel, cobbles or scoria, to moderately deep soils with little rock. Soils are moderately to well-drained, sometimes calcareous, with pH of 6.8-7.7. Soil texture ranges from gravelly, sandy loams to clay. Parent material may include alluvium, colluvium, residuum, glacial deposits or loess derived from lava, basalt, granite, quartz diorite, calcareous sandstone, limestone, acid shale, bentonite, marlstone and other volcanic materials. Litter, moss and lichen are important ground cover in some stands.
Geographic Range: This widespread dry grassland alliance occurs in the northwestern Great Plains and mountain and foothill slopes on both sides of the Continental Divide in the Central Rockies in northwestern Montana, extending north into the montane zone of Alberta, west into Idaho, and south to the Grand Teton Mountains of northwestern Wyoming. Stands also occur in the Okanogan Highlands of northeastern Washington and southern British Columbia and in the Columbia Basin of south-central Washington and north-central Oregon, extending west into the foothills of the eastern Cascades and east into foothills and canyon slopes of northeastern Oregon and western Idaho. It also occurs in northeastern California.

Nations: CA,US

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


Confidence Level: Moderate

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.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 CEGL001616 Idaho Fescue - Parsnip-flower Buckwheat Grassland CEGL001616 2.B.2.Nf.2.c
Association CEGL001619 Idaho Fescue - Hound''s-tongue Hawkweed Grassland CEGL001619 2.B.2.Nf.2.c
Association CEGL001624 Idaho Fescue - Bluebunch Wheatgrass Grassland CEGL001624 2.B.2.Nf.2.c
Association CEGL001662 Bluebunch Wheatgrass - Arrowleaf Balsamroot - Sandberg Bluegrass Grassland CEGL001662 2.B.2.Nf.2.c
Association CEGL001665 Bluebunch Wheatgrass - Threadleaf Sedge Grassland CEGL001665 2.B.2.Nf.2.c
Association CEGL001668 Bluebunch Wheatgrass - Parsnip-flower Buckwheat Grassland CEGL001668 2.B.2.Nf.2.c
Association CEGL001669 Bluebunch Wheatgrass - Idaho Fescue Canyon Grassland CEGL001669 2.B.2.Nf.2.c
Association CEGL001677 Bluebunch Wheatgrass - Sandberg Bluegrass Grassland CEGL001677 2.B.2.Nf.2.c
Association CEGL001678 Bluebunch Wheatgrass - Sandberg Bluegrass Lithosolic Grassland CEGL001678 2.B.2.Nf.2.c
Association CEGL001679 Bluebunch Wheatgrass - Needle-and-Thread Grassland CEGL001679 2.B.2.Nf.2.c
Association CEGL001782 (Serrate Balsamroot) - Sandberg Bluegrass Grassland CEGL001782 2.B.2.Nf.2.c
Association CEGL001790 Cous Biscuitroot - Sandberg Bluegrass Grassland CEGL001790 2.B.2.Nf.2.c
Association CEGL005607 Bluebunch Wheatgrass - Oniongrass Grassland CEGL005607 2.B.2.Nf.2.c
Association CEGL005609 Bluebunch Wheatgrass - Tapertip Hawk''s-beard Grassland CEGL005609 2.B.2.Nf.2.c
Concept Lineage: This new alliance includes associations from Old Alliance V.A.5.N.d. Festuca idahoensis Herbaceous Alliance (A.1251), Old Alliance V.A.5.N.d. Pseudoroegneria spicata Herbaceous Alliance (A.1265), and Old Alliance V.A.5.N.f. Poa secunda Herbaceous Alliance (A.1291).

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: > Agropyron spicatum Series (Tisdale 1986)
> Agropyron spicatum Series (Johnson and Simon 1987)
> Agropyron spicatum Series (Tweit and Houston 1980)
>< Festuca idahoensis (Idaho fescue grassland) Alliance (Sawyer et al. 2009) [41.250.00]
> Pseudoroegneria spicata (Bluebunch wheat grass grassland) Alliance (Sawyer et al. 2009) [41.040.00]
> Pseudoroegneria spicata Grasslands (Chappell et al. 1997)
> Bluebunch Wheatgrass Series (Sawyer and Keeler-Wolf 1995)
>< Idaho Fescue Series (Sawyer and Keeler-Wolf 1995)
Concept Author(s): K.A. Schulz, in Faber-Langendoen et al. (2013)

Author of Description: K.A. Schulz

Acknowledgements: No Data Available

Version Date: 03-14-14
  • Chappell, C., R. Crawford, J. Kagan, and P. J. Doran. 1997. A vegetation, land use, and habitat classification system for the terrestrial and aquatic ecosystems of Oregon and Washington. Unpublished report prepared for Wildlife habitat and species associations within Oregon and Washington landscapes: Building a common understanding for management. Prepared by Washington and Oregon Natural Heritage Programs, Olympia, WA, and Portland, OR. 177 pp.
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Johnson, C. G., Jr., and S. A. Simon. 1987. Plant associations of the Wallowa-Snake Province Wallowa-Whitman National Forest. Technical Paper R6-ECOL-TP-255A-86. USDA Forest Service, Pacific Northwest Region, Wallowa-Whitman National Forest. 399 pp. plus appendices.
  • Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.
  • Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.
  • Tisdale, E. W. 1986. Canyon grasslands and associated shrublands of west-central Idaho and adjacent areas. Bulletin No. 40. Forest, Wildlife and Range Experiment Station, University of Idaho, Moscow. 42 pp.
  • Tweit, S., and K. Houston. 1980. Grassland and shrubland habitat types of the Shoshone National Forest. USDA Forest Service, Rocky Mountain Region, Shoshone National Forest.