Name:
Pinus edulis / Sparse Understory Forest
Reference:
Western Ecology Working Group of...
Description:
These forests and woodlands occur in foothills, mesas, plateaus and mountains of New Mexico, Arizona, Colorado and Utah. Sites are flat to moderately sloping. Stands frequently occur on less xeric, northern and eastern exposures, but can occur on all aspects. Elevations range from 1850-2290 m (6065-7500 feet). Substrates are variable, but often include eroded, shallow, coarse-textured substrates such as cinder (but not rock outcrops) that limit understory growth. Cover of tree litter is dense in some stands, but in others the ground surface is characterized by exposed soil and gravel with widely scattered grass patches and litter. A moderately dense (over 25% cover) to dense tree canopy with little or no understory characterizes the vegetation. The tree canopy is dominated by <i>Pinus edulis</i>. Other trees may codominate especially one or more of several species of <i>Juniperus</i> that vary with geography. If other species of <i>Pinus</i> are present they do not codominate. The sparse understory (<10% cover and usually <2%) may include scattered shrubs, dwarf-shrubs, succulents, grasses and forbs, such as <i>Ageratina herbacea, Cercocarpus montanus, Fallugia paradoxa, Rhus trilobata, Gutierrezia sarothrae, Achnatherum hymenoides</i>, and species of <i>Poa, Opuntia, Yucca, Penstemon</i>, and <i>Phlox</i>. The original concept of this association was of a nearly closed, <i>Pinus edulis</i>-dominated tree canopy that shaded out understory vegetation and often occurred on relatively mesic sites with high tree growth potential. However, the association also now includes fire-suppressed stands, woodlands growing on eroded or "badlands" substrates, and/or over-grazed stands that lack understory vegetation.
Accession Code:
VB.CC.33046.CEGL000795
Plot-observations of this Community Concept:
0
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