Name:
Pinus flexilis / Festuca arizonica - Muhlenbergia montana Woodland
Reference:
Western Ecology Working Group of...
Description:
This association is only known from the Sangre de Cristo Range in southern Colorado, but likely is more widespread in the southern Rocky Mountains. Stands occur on colluvial slopes and ridges between 2780 and 3150 m in elevation. Sites are located on warm aspects, southeast through northwest, and on slopes ranging from 6° on a high ridge to 38° on a steep colluvial slope. The ground cover is generally over 50% bare soil, gravel and rock, with about 30% litter and <10% each of basal area and wood (although one sample plot had 76% litter and few rocks). Soils are well-drained and high in sand. Past fires were noted at several plots taken at Great Sand Dunes National Park. Vegetation is characterized by an open tree canopy dominated by <i>Pinus flexilis</i> with an herbaceous understory dominated by graminoids <i>Festuca arizonica</i> and <i>Muhlenbergia montana</i>. The tree strata may have scattered individuals of <i>Pinus ponderosa, Pinus aristata, Pinus edulis, Abies concolor, Pseudotsuga menziesii</i>, or <i>Juniperus scopulorum</i>. Stands on ridgetops or otherwise on the edge of sharp gradients are more prone to mixing. Short shrubs are often present with up to 15% cover, but do not exceed herbaceous cover. Species can include <i>Symphoricarpos</i> spp., <i>Juniperus communis, Ribes cereum, Cercocarpus montanus</i>, and <i>Rosa woodsii</i>. The herbaceous layer is diverse, often supporting more than 30-40 forb and graminoid species. <i>Festuca arizonica</i> and <i>Muhlenbergia montana</i> typically codominate, but one or the other may be absent. Frequently encountered graminoids include <i>Koeleria macrantha, Elymus elymoides, Blepharoneuron tricholepis, Carex siccata (= Carex foenea), Poa fendleriana</i>, and <i>Bromus ciliatus</i>. Forbs found in at least half of the plots include <i>Heterotheca villosa, Packera fendleri, Achillea millefolium var. occidentalis, Eriogonum alatum, Penstemon</i> sp., <i>Artemisia frigida, Potentilla hippiana, Astragalus</i> sp., <i>Castilleja linariifolia, Antennaria parvifolia, Erigeron</i> spp., and <i>Eriogonum jamesii</i>. Other trace species include <i>Artemisia ludoviciana, Arenaria fendleri, Clematis hirsutissima var. scottii, Frasera speciosa, Machaeranthera bigelovii, Oreochrysum parryi, Sedum lanceolatum, Comandra umbellata, Draba smithii, Penstemon linarioides ssp. coloradoensis, Thermopsis</i> sp., and many others. Stands may border or contain inclusions of ~<i>Festuca arizonica - Muhlenbergia montana</i> Herbaceous Vegetation (CEGL001606)$$.
Accession Code:
VB.CC.31694.CEGL005416
Plot-observations of this Community Concept:
0
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