Name:
Atriplex gardneri / Achnatherum hymenoides Dwarf-shrubland
Reference:
Western Ecology Working Group of...
Description:
This association occurs as small, scattered stands on shale badlands and soils in Utah, Colorado, Montana and possibly Wyoming and Oregon. Stands occupy low hills, plains, mesatops and swales with gentle to moderate slopes and variable aspects between 1525 and 2200 m (5000-7220 feet) elevation. The unvegetated surface consists almost entirely of bare ground or shale fragments with little to no litter; in Utah, the surface is modified by a slopewash of gravels from nearby pediments. Soils are shallow, alkaline silty clay loams, derived from marine or freshwater shales of the Chinle, Mancos, Green River, Wasatch, Morrison or other formations. This is generally a sparsely vegetated community, with total vegetation cover rarely exceeding 25% and often as low as 5%. The vegetation is characterized by a sparse canopy of the dwarf-shrub <i>Atriplex gardneri</i> with between 1 and 10% cover. Associated shrubs are limited to scattered individuals of <i>Chrysothamnus viscidiflorus, Ericameria nauseosa, Ephedra viridis, Ephedra torreyana, Eriogonum microthecum, Krascheninnikovia lanata</i>, and <i>Picrothamnus desertorum</i>, which together may contribute another 5-10% cover to the dwarf-shrub canopy. The herbaceous layer may have greater cover than the shrub layer, up to 25%, but is often reduced as a result of grazing. It generally only contains a few species, among which <i>Achnatherum hymenoides</i> is the most conspicuous. Other grasses include <i>Elymus elymoides, Pleuraphis jamesii</i>, and <i>Poa secunda</i>; the forb component is sparse and variable, with species such as <i>Phlox hoodii, Lappula occidentalis (= Lappula redowskii)</i>, and <i>Sphaeralcea</i> spp. contributing only trace cover.
Accession Code:
VB.CC.34373.CEGL001444
Plot-observations of this Community Concept:
0
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