Name:
Pinus flexilis - Juniperus scopulorum Rocky Mountain Foothill Woodland Group
Reference:
NatureServe Biotics 2019
Description:
This group occurs in foothills and may extend into lower montane zones in the Rocky Mountains from southern Alberta and northern Montana south to central Colorado and on escarpments across Wyoming extending out into the western Great Plains. Elevation ranges from 1000-2400 m. These are rock outcrop, escarpment and patchy woodlands, occurring generally below continuous forests of <i>Pseudotsuga menziesii</i> or <i>Pinus ponderosa</i>. Climatologically, the region is semi-arid and has a continental regime of hot summers and cold winters. Precipitation patterns are variable, but snow is common in winter, and spring rains are an important contributor. These woodlands are restricted to shallow soils and fractured bedrock derived from a variety of parent material, including limestone, sandstone, dolomite, granite, and colluvium. An unusual plant association in Idaho occurs on relatively unweathered mafic lava flows, where it occurs in mesic pockets within the fractured lava. In all cases, soils have a high rock component (typically over 50% cover) and are coarse- to fine-textured, often gravelly and calcareous. Slopes are typically moderately steep to steep. At higher elevations, it is limited to the most xeric aspects on rock outcrops, and at lower elevations to the relatively mesic north aspects. Fire is infrequent and spotty because the rocky substrates prevent development of a continuous vegetation canopy needed to spread. Vegetation is characterized by an open-tree canopy or patchy woodland that is dominated by either <i>Pinus flexilis, Juniperus osteosperma</i>, or <i>Juniperus scopulorum</i>. This group generally occurs outside of the range of <i>Pinus edulis</i>, which is not present. A sparse to moderately dense short-shrub layer, if present, may include a variety of shrubs, such as <i>Artemisia nova, Artemisia tridentata, Cercocarpus ledifolius, Cercocarpus montanus, Ericameria nauseosa, Juniperus horizontalis, Purshia tridentata</i>, or <i>Rhus trilobata</i>. Herbaceous layers are generally sparse, but range to moderately dense, and are typically dominated by perennial graminoids such as <i>Bouteloua gracilis, Hesperostipa comata, Koeleria macrantha, Piptatheropsis micrantha, Poa secunda</i>, or <i>Pseudoroegneria spicata</i>. Within this group, there may be small patches of grassland or shrubland composed of some of the above species.
Accession Code:
urn:lsid:vegbank.org:commConcept:40005-{445045EE-CD06-4BBF-89FF-54C2DDE94819}
Plot-observations of this Community Concept:
0
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