Name:
Artemisia tridentata - Artemisia tripartita ssp. tripartita - Purshia tridentata Steppe & Shrubland Macrogroup
Reference:
NatureServe Biotics 2019
Description:
This sagebrush shrubland and shrub-steppe macrogroup is widely distributed in the western U.S. It has an open to dense (10-80% cover) short-shrub canopy (<2 m tall) dominated by <i>Artemisia tridentata</i>. <i>Purshia tridentata</i> is less widespread but often dominates or codominates with <i>Artemisia tridentata</i>, especially in relatively mesic and montane stands. The subspecies of <i>Artemisia tridentata</i> vary by habitat and geographic range. The most widespread taxa are <i>Artemisia tridentata ssp. wyomingensis</i> and <i>Artemisia tridentata ssp. tridentata</i>. Some stands are codominated by associated shrub species <i>Atriplex canescens, Atriplex confertifolia, Ephedra nevadensis, Ephedra viridis, Ericameria nauseosa, Grayia spinosa, Sarcobatus vermiculatus</i>, or <i>Tetradymia canescens</i>. <i>Artemisia tridentata ssp. tridentata, Artemisia tridentata ssp. xericensis</i>, and <i>Artemisia tripartita ssp. tripartita</i> are characteristic of relatively mesic environments. Mesic associates include <i>Peraphyllum ramosissimum, Prunus virginiana</i>, and <i>Symphoricarpos</i> spp. At montane elevations, <i>Artemisia tridentata ssp. vaseyana, Artemisia cana</i>, and related taxa such as <i>Artemisia tridentata ssp. spiciformis</i> dominate, sometimes with <i>Purshia tridentata</i> codominating or dominating stands. <i>Amelanchier utahensis</i> and <i>Symphoricarpos oreophilus</i> are common montane associates. The understory of this macrogroup is variable and characterized by a sparse to dense (5-50% cover) herbaceous layer that is dominated by a variety of perennial graminoid associates. On xeric sites <i>Achnatherum hymenoides, Hesperostipa comata, Poa secunda</i>, and other semi-desert associates are common. On relatively mesic or montane sites, associates include <i>Achnatherum occidentale, Bromus carinatus, Calamagrostis rubescens, Carex pensylvanica, Danthonia intermedia, Deschampsia cespitosa, Elymus trachycaulus, Festuca arizonica, Festuca idahoensis, Leucopoa kingii, Leymus cinereus, Poa fendleriana</i>, and <i>Pseudoroegneria spicata</i>. Shrub-steppes characterized by an open shrub canopy and abundant native graminoid understory are more common in the less xeric northern extent, at montane elevations and mesic microsites such as along drainages. Shrublands are more common in the drier southern extent with the core distribution in the Great Basin and Colorado Plateau. Stands are found as low as 500 m elevation in the northwestern Great Plains and up to 2500 m in the Rocky Mountains and Colorado Plateau. Xeric stands occur on flat to steeply sloping upland slopes on alluvial fans and terraces, toeslopes, lower and middle slopes, draws, badlands, foothills, and rocky slopes. Mesic stands occur on stream terraces, point bars, valley floors, alluvial fans, floodplains, washes, gullies, stabilized dunes, mesic uplands, and swales. Montane stands occur on stony flats, broad ridgetops, and mountain slopes. All aspects are represented, but occurrences at higher elevations may be restricted to south- or west-facing slopes. Soils vary from deep and well-developed to shallow rocky and poorly developed substrates.
Accession Code:
urn:lsid:vegbank.org:commConcept:40531-{79AD9120-E564-4932-B561-9E8BDFA754F4}
Plot-observations of this Community Concept:
0
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