Name:
Pinus ponderosa / Carex inops ssp. heliophila Woodland
Reference:
Western Ecology Working Group of...
Description:
This ponderosa pine / sedge woodland is found in the Black Hills region, along the Rocky Mountain Front Range from Montana to Colorado, and in north-central and western New Mexico. Along the Rocky Mountains, this association occurs from the foothills to 2900 m (9500 feet) in elevation, although its elevation decreases farther north. Stands occur in relatively mesic savanna habitats, on gentle to moderate south- and west-facing slopes. In north-central New Mexico, this association occurs at mid-elevation (1920-2560 m [6300-8400 feet]) on sites with moderate to high solar exposure that increases with elevation. Aspects tend to be more northerly at lower elevation, more southerly on higher sites. Slopes range from gentle to moderate (8-20%), and occasionally very steep (>50%). Substrates are variable and may include the following soil types: poorly-developed and rocky Inceptisols from rhyolitic colluviums; finer-textured Alfisols from rhyolitic slope alluvium; gravely Mollisols from rhyolite tuff; or pumice slope alluvium. Some sites are predominantly rock outcrop. At El Malpais National Monument in west-central New Mexico, it typically occurs on gently rolling basalt lava plateaus and collapse features, though occasionally it is found on steep sideslopes of cinder cones and cinder fields. The ground surface is characterized by scattered bunchgrasses and sedges intermixed with litter, and some sites are very rocky. Diagnostic characteristics of this association are the open canopy of <i>Pinus ponderosa</i> over a graminoid layer dominated by <i>Carex inops ssp. heliophila</i>. Occasional canopy associates include <i>Juniperus scopulorum, Pseudotsuga menziesii</i>, or <i>Quercus macrocarpa</i> in the subcanopy, depending on which portion of the geographic range the stand is found. The understory has a characteristically sparse (<5%) cover of shrubs, most frequently <i>Quercus x pauciloba, Ribes cereum</i>, and <i>Rhus trilobata</i>. The herbaceous layer is dominated by <i>Carex inops ssp. heliophila</i>, with inclusions of <i>Danthonia spicata, Poa fendleriana, Muhlenbergia montana,</i><i> Schizachyrium scoparium, Pseudoroegneria spicata</i>, and <i>Bouteloua gracilis</i>, generally in areas with more open canopies. Within Bandelier National Monument in north-central New Mexico, canopy cover ranges from open woodland to closed-canopied forests (25% to >60% cover). Density of mature <i>Pinus ponderosa</i> is moderate and reproduction is rare or absent. Other conifers such as <i>Abies concolor, Pseudotsuga menziesii</i>, and <i>Pinus flexilis</i> are rare or absent in the overstory. Shrubs are a minor component of the stands. The herbaceous layer is rich in species but variable in cover. The most diagnostic and abundant graminoid is <i>Carex inops ssp. heliophila</i>, with other abundant species including deer sedges (<i>Carex occidentalis, Carex rossii</i>, and <i>Carex geophila</i>). While forbs are diverse, composition is variable from stand to stand and usually less than 5% total cover.
Accession Code:
VB.CC.32899.CEGL000849
Plot-observations of this Community Concept:
0
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