Name:
Pinus edulis - Juniperus osteosperma / Shrub Understory Foothill & Lower Montane Dry-Mesic Woodland Alliance
Reference:
NatureServe Biotics 2019
Description:
This woodland alliance is characterized by diagnostic tree species <i>Pinus edulis</i> that forms an open to dense tree layer often with <i>Juniperus osteosperma</i> or, less frequently, <i>Juniperus monosperma</i> within the range of <i>Juniperus osteosperma</i> in northern Arizona. <i>Juniperus osteosperma</i> may also dominate stands as long as there is significant presence of <i>Pinus edulis</i> (not accidental) to characterize the stand as a pinyon-juniper stand and not the more xeric, typically lower elevation <i>Juniperus osteosperma</i> woodland. At higher elevations and relatively mesic sites, such as along drainages, <i>Juniperus scopulorum</i> may be present and sometimes dominant. Other conifers are absent or accidental with very low cover. The understory is characterized by relatively mesic shrubs that typically form an open to moderately dense layer. Diagnostic shrubs include <i>Amelanchier utahensis, Arctostaphylos patula, Arctostaphylos pungens, Artemisia tridentata ssp. tridentata, Artemisia tridentata ssp. vaseyana, Artemisia tridentata ssp. wyomingensis, Cercocarpus ledifolius, Quercus gambelii</i>, and <i>Symphoricarpos oreophilus</i>. The herbaceous layer is sparse to moderate and composed of grasses often with diverse, but low cover of forbs. Common species may include <i>Achnatherum hymenoides, Bouteloua gracilis, Hesperostipa comata, Hesperostipa neomexicana, Poa fendleriana, Poa secunda, Pleuraphis jamesii</i>, and <i>Pseudoroegneria spicata</i>. The non-native, invasive annual grass <i>Bromus tectorum</i> may become abundant in disturbed stands and dominate the herbaceous layer of highly disturbed stands. These woodlands occur on warm, dry-mesic sites on mountain slopes and foothills and in the higher plateaus and mountains in the Colorado Plateau and the west slope of the southern Rocky Mountains. Stands occur on flat to moderate slopes along drainages, on mesatops, and on moderate to steep, sometimes rocky slopes of foothills, mountains and canyons, especially in draws where soil moisture is concentrated, or on northern aspects or where shaded by upper canyon walls. Aspects are variable and elevations range from 1500-2770 m (4920-9090 feet). The soils are variable but tend to be shallow, gravelly and rapidly drained, ranging from sandy loams to silt clay loams. Litter from shrubs may be extensive (over 50% cover). Parent materials include alluvial, colluvial or eolian deposits derived from sandstone, shale, limestone, granite quartzite and rhyolite.
Accession Code:
urn:lsid:vegbank.org:commConcept:38791-{FB6943DE-C6AD-40C3-B9B3-A5E9C13284A4}
Plot-observations of this Community Concept:
0
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