Name:
Ambrosia deltoidea Shrubland Alliance
Reference:
Western Ecology Working Group of...
Description:
Shrublands included in this alliance occur on rocky bajadas and ridges in the Arizona Uplands of the Sonoran Desert from 600-800 m in elevation. Climate is hot and dry in summer, and hard freezes are rare in the winter. Mean annual precipitation ranges from 18-32 cm. Although it varies greatly from year to year, the annual precipitation has a bimodal distribution: about half of the rain falls during July to September and a third falls from December to March. Sites where these vegetation types are found are on gentle to moderately steep, east-facing hillslopes, middle and upper bajadas, and ridges. Substrates are derived from alluvium, and are generally shallow, coarse-textured, and gravelly. Stands occur at elevations above the Sonoran desertscrub, dominated by Larrea tridentata or Ambrosia dumosa, and below the interior chaparral, dominated by Quercus turbinella, Cercocarpus montanus or Arctostaphylos pungens. The sparse to moderately dense canopy (30-45% cover) of shrubs is dominated or codominated by the broad-leaved xeromorphic, deciduous shrub Ambrosia deltoidea. Codominant species include a mix of microphyllous evergreen and broad-leaved deciduous shrubs and small trees, such as Simmondsia chinensis, Parkinsonia microphylla, Encelia farinosa, Larrea tridentata, Krameria grayi, Jatropha cardiophylla, Lycium spp. and Fouquieria splendens. Tall woody cacti, such as Carnegia gigantea, Opuntia fulgida, Opuntia bigelovii, Opuntia acanthocarpa, Opuntia engelmannii, Opuntia leptocaulis, or Stenocereus thurberi, are present and conspicuous, with heights up to 10 m. The graminoid layer is generally sparse.
Accession Code:
VB.CC.22127.AMBROSIADELTOID
Plot-observations of this Community Concept:
0
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