Name:
Pinus ponderosa / Ribes cereum Forest
Reference:
NatureServe Biotics 2019
Description:
These montane evergreen stands are common on the eastern side of the Continental Divide in Rocky Mountain National Park between 2200 and 2840 m (7215-9300 feet) elevation. They often occur on the southern flank of lateral moraines and on other dry, south-facing slopes at pitches that are moderate to somewhat steep (10-49%). Soils are rapidly drained loamy sands derived from granitic parent material. Exposed bedrock, boulders, and small rocks can make up 10-25% of the ground surface within the stand, and another 25-75% of the ground is covered in long needle litter and duff. <i>Pinus ponderosa var. scopulorum</i> forms an open canopy within this association. Trees reach between 10 and 20 m in height with areal coverage of 20-40%. In addition to <i>Pinus ponderosa var. scopulorum</i>, scattered individuals of <i>Pseudotsuga menziesii</i> can contribute up to 10% cover, and <i>Pinus contorta var. latifolia, Pinus flexilis</i>, and <i>Juniperus scopulorum</i> can be found in low concentrations. The association is defined by a consistent yet inconspicuous shrub layer dominated by <i>Ribes cereum</i> that covers only 20% of the surface area within the stand. The shrubs generally grow between 0.5-1 m tall and are dispersed throughout the stand. Several other shrub species can occur, but all with <5% cover. These species include <i>Arctostaphylos uva-ursi, Ceanothus fendleri, Juniperus communis var. montana, Mahonia repens, Prunus virginiana var. melanocarpa, Purshia tridentata</i>, and <i>Rubus deliciosus</i>. Herbaceous cover within the association can be variable. Some stands have up to 50% cover of dry montane graminoids such as <i>Muhlenbergia montana</i> and <i>Carex rossii</i>; other stands have only 10% herbaceous cover with a heavy litter layer blanketing the understory. Common forbs, nearly always found in trace amounts, include <i>Antennaria</i> spp., <i>Artemisia ludoviciana, Draba</i> spp., <i>Eriogonum umbellatum var. umbellatum, Geranium caespitosum var. caespitosum, Potentilla fissa, Potentilla hippiana, Sedum lanceolatum ssp. lanceolatum</i>, and <i>Thermopsis divaricarpa</i>. The invasive grasses <i>Bromus tectorum</i> and <i>Poa pratensis</i> have also been found in trace amounts within stands of this association.
Accession Code:
urn:lsid:vegbank.org:commConcept:29108-{F0EC4398-398A-45B5-9267-D3591842633C}
Plot-observations of this Community Concept:
0
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