Name:
Amelanchier alnifolia / Festuca idahoensis - Pseudoroegneria spicata Grassland & Shrubland Macrogroup
Reference:
NatureServe Biotics 2019
Description:
This macrogroup occurs in the foothills and mountains throughout the Central Rockies and montane Intermountain West region, from central and eastern Wyoming north and west into British Columbia and Alberta. This includes the "island ranges" of central Montana, though it is not common west to the East Cascades. It is broadly defined structurally and is composed of shrub- and/or herbaceous-dominated stands forming shrublands (>25% cover), shrub-steppe (10-25% cover), or open grasslands (shrubs <10% cover). Characteristic shrubs between 1 and 3 m in height are <i>Acer glabrum, Amelanchier alnifolia, Holodiscus discolor, Menziesia ferruginea, Physocarpus malvaceus, Prunus emarginata, Prunus virginiana, Rhus glabra, Rhus trilobata, Ribes lacustre, Rosa nutkana, Rosa woodsii, Rubus parviflorus, Sambucus nigra ssp. cerulea, Spiraea</i> spp., and <i>Symphoricarpos albus</i>. Dwarf-shrubs (<0.3 m tall) composed of <i>Vaccinium cespitosum, Vaccinium myrtillus, Vaccinium scoparium</i>, and <i>Vaccinium membranaceum</i> may be also form the dominant and characteristic woody layer. Grasslands are dominated by <i>Festuca idahoensis</i> and <i>Pseudoroegneria spicata</i>, with <i>Festuca campestris</i> increasing northward in Alberta. Other characteristic herbaceous graminoids present include <i>Achnatherum scribneri, Achnatherum hymenoides, Carex geyeri, Carex filifolia, Carex petasata, Danthonia</i> spp., <i>Elymus lanceolatus, Festuca campestris, Hesperostipa comata, Koeleria macrantha, Leucopoa kingii, Leymus cinereus, Pascopyrum smithii</i>, and <i>Poa secunda</i>. Associated forbs are numerous and include species of <i>Arnica, Antennaria, Erigeron, Eriogonum, Gaillardia, Galium, Geum, Heuchera, Liatris, Lithospermum, Lupinus, Lomatium, Oxytropis, Penstemon, Phlox, Potentilla</i>, and <i>Solidago</i>. On dry, sites with low grazing pressure, <i>Selaginella densa</i> and lichens provide significant ground cover between clumps of grasses. Non-native grasses can also be abundant and include <i>Phleum pratense, Bromus inermis</i>, and <i>Poa pratensis</i>. The herbaceous layer of shrublands has similar species composition to many of the grasslands in this macrogroup, except for the mesic shrublands with typically more mesic species such as <i>Heracleum maximum, Luzula glabrata</i>, or some other species such as <i>Chamerion angustifolium</i> and <i>Xerophyllum tenax</i>. <i>Alnus</i> spp. may occur in avalanche slopes. Stands occur as extensive foothill and valley grasslands and shrublands below the lower treeline and extend up into the high montane zones. Climate is temperate with predominantly dry summers and cold winters. Annual precipitation is approximately 20-80 cm, and primarily occurs in the winter as snow or rain, with moisture increasing with elevation. These communities tend to occur on gentle to steep-gradient slopes. Sites are highly variable. Grasslands tend to occur on warmer, drier sites and drier micro-climates, especially at higher elevation. Shrublands and dwarf-shrublands often occur on cooler, more mesic sites than grasslands. These shrubland communities also develop near talus slopes as garlands, at the heads of dry drainages, toeslopes in the moist shrub-steppe and steppe zones, and as smaller patches on dry sites that are marginal for tree growth and that have typically also experienced fire. Some site may occupy avalanche areas. Parent materials include basalt colluvium, loess, lava and tuff, glacial outwash composed of fine silts and clays of moderate depth. Soils range from poorly developed, well-drained alluvial or colluvial sands with a high percentage of rock fragments to be moderately deep, silt loam or loam with few rock fragments (less than 15% by volume and no rock cover). This macrogroup also includes grasslands from eastern Washington and Oregon commonly known as Palouse Prairie, which is characterized by rolling topography composed of loess hills and plains over basalt plains.
Accession Code:
urn:lsid:vegbank.org:commConcept:40468-{7D7FB34B-DFDE-46DA-8C21-F16E3F71ECC5}
Plot-observations of this Community Concept:
0
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