Name:
Ephedra torreyana - Artemisia bigelovii Sparse Vegetation
Reference:
Western Ecology Working Group of...
Description:
This Colorado Plateau association has been described from Petrified Forest National Park in northern Arizona and Capitol Reef National Park in southeastern Utah, where it is widespread. Stands occur on plateaus, mesas, ridges, hills, cliffs, rocky colluvial slopes, benches, terraces, and near drainage channels that are gently sloping to steep (3-50%) between 1402 and 1915 m elevation on all aspects. The unvegetated surface has moderate to high cover of gravel and low to moderate cover of large rocks and litter. Cryptogams are typically absent, but one stand has 75% cover. Parent materials include sandstones and shale. Soils are rapidly drained and variable in texture, including loams, sands, and clays, but are unified by a coating of fine to coarse gravels composed of sandstone, shale, basalt, or petrified wood. The vegetation is typically sparse (<10% total cover) and is characterized by an open, mixed shrub canopy that is dominated or codominated by <i>Ephedra torreyana</i> and <i>Artemisia bigelovii</i>. Locally, shrub cover may range up to about 20% cover, but in general, shrub cover is <10% with scattered grasses and forbs (<5% cover). Additionally, total cover may temporarily exceed 10% following rain events due to blooms of annuals. Associated shrubs are diverse but characteristically include all or some of <i>Atriplex confertifolia, Chrysothamnus viscidiflorus, Ephedra viridis, Ericameria nauseosa, Eriogonum corymbosum</i>, and <i>Gutierrezia sarothrae</i>. Occasional <i>Juniperus osteosperma</i> may be present as saplings. The herbaceous layer is characteristically depauperate and sparse. Species recorded from plots include <i>Achnatherum hymenoides, Aristida purpurea, Bouteloua gracilis, Hesperostipa comata</i>, and <i>Pleuraphis jamesii</i>. Forbs present include <i>Phacelia crenulata</i> and <i>Tetraneuris acaulis</i>. The exotic annual grass <i>Bromus tectorum</i> is common in many of the sampled stands.
Accession Code:
VB.CC.32036.CEGL002350
Plot-observations of this Community Concept:
0
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