Name:
A.869
Reference:
EcoArt 2002
Description:
This alliance occurs primarily in arid and semi-arid areas of the southwestern U.S. from western Texas to southern and eastern California and into Chihuahua, Mexico. It is also found in the western Great Plains to the Great Basin from western Kansas, Colorado, and Wyoming to Utah, Nevada and eastern Oregon. Associations in this alliance vary throughout the range and occur in a variety of environmental settings. In western Texas, this alliance occupies alkaline flats, depressions among gypsum ridges, saline or sandy soils. Overall, shrublands in this alliance occur on lowland and upland sites with elevation ranging from 75 m below sea level to 2400 m. Lowland sites include alluvial flats, drainage terraces, playas, washes and interdune basins. Upland sites include bluffs and gentle to moderately steep, sandy or rocky slopes. Stands occur on all aspects. Soils are variable with depths ranging from shallow to moderately deep, and texture ranging from sand to loam to clay. The lowland sites may be moderately saline or alkaline. ^Stands typically have a sparse to moderately dense (10-60% cover) short-shrub canopy (approximately 1.5 m tall) that is dominated by the facultative deciduous, xeromorphic shrub ~Atriplex canescens$, with bare ground usually dominating the ground surface. Associated shrubs may include ~Artemisia bigelovii, Artemisia tridentata, Ephedra viridis, Krascheninnikovia lanata, Purshia stansburiana (= Purshia mexicana var. stansburiana), Psorothamnus polydenius, Parthenium confertum, Sarcobatus vermiculatus$, and species of ~Chrysothamnus, Ericameria$, and ~Lycium$. Dwarf-shrubs, such as ~Gutierrezia sarothrae$ or ~Eriogonum$ spp., may be common in some stands. The sparse to moderately dense graminoid layer (1-60% cover) is typically dominated by warm-season, medium-tall and short grasses. The species present depend on geographic range of the grasses and past land use. Species may include ~Bouteloua gracilis, Distichlis spicata, Elymus elymoides, Hesperostipa comata, Pleuraphis jamesii (= Hilaria jamesii), Achnatherum hymenoides (= Oryzopsis hymenoides), Muhlenbergia porteri, Scleropogon brevifolius, Pascopyrum smithii$, and ~Sporobolus$ spp. Forb cover is generally sparse, but annual forbs such as ~Calycoseris parryi$ may be abundant in wet years. Common forbs include species of ~Sphaeralcea, Dalea, Cymopterus, Chenopodium, Kochia, Iva, Picradeniopsis$, and ~Ratibida$. Cacti from the genus ~Opuntia$ are associated species in some stands. Trees are typically not present, but occasionally scattered ~Juniperus$ spp. occur. Very little is known about the expression of this alliance in the Midwest.
Accession Code:
VB.CC.2497.A869
Plot-observations of this Community Concept:
0
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