Name:
Larrea tridentata Chihuahuan Desert Scrub Alliance
Reference:
NatureServe Biotics 2019
Description:
This alliance is the extensive desert scrub that occurs in the broad desert basins and plains extending up onto dissected gravelly alluvial fans and piedmonts (bajadas), and foothills in the Chihuahuan Desert (below the chaparral zone). The vegetation is dominated by xeromorphic deciduous and microphyllous evergreen shrubs up to 2 m tall, forming a moderate to sparse shrub layer (<10% cover on extremely xeric sites) dominated by <i>Larrea tridentata</i>, often covering entire landscapes in near monotypic stands. Stands can also be codominated by other desert scrub species such as <i>Agave lechuguilla, Aloysia wrightii, Atriplex canescens, Dasylirion leiophyllum, Ephedra aspera, Flourensia cernua, Fouquieria splendens, Hechtia texensis, Jatropha dioica var. graminea, Lycium berlandieri, Menodora scabra, Mimosa aculeaticarpa var. biuncifera, Opuntia engelmannii, Parthenium incanum, Prosopis glandulosa, Tiquilia canescens, Tiquilia greggii</i>, and <i>Yucca</i> spp. If present, <i>Prosopis glandulosa</i> does not dominate the shrub layer, but may codominate in mixed stands with <i>Larrea tridentata</i>. Grasses are common but generally have lower cover than shrubs. Common species may include <i>Bouteloua eriopoda, Bouteloua gracilis, Bouteloua ramosa, Dasyochloa pulchella, Muhlenbergia porteri, Pleuraphis mutica</i>, and <i>Scleropogon brevifolius</i>. Some shrublands have a sparse understory, sometimes with a pebbly desert pavement on the soil surface. Climate is arid to semi-arid with hot summers. Freezing temperatures may occur during the winter. Mean annual precipitation is approximately 28 cm. Precipitation can vary greatly from year to year with drought not uncommon. Annual precipitation has bimodal distribution with about a third of the annual precipitation occurring in late winter and two-thirds in July through October. The summer rain often occurs as high-intensity convective storms. The most arid season is late spring and early summer. Substrates are typically coarse-textured loams on gravelly plains and slopes. Soils are alluvial, typically non-saline, and frequently calcareous, sometimes with a petrocalic layer and are often derived from limestone and sandstone, or to a lesser degree, igneous rocks. Stands can extend upslope onto colluvial slopes with cobbly skeletal soils. Over the last century it has recently expanded into former desert grasslands in the northern portion of its range.
Accession Code:
urn:lsid:vegbank.org:commConcept:38452-{454E82CA-277F-469F-9180-A61856DF6EF9}
Plot-observations of this Community Concept:
0
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