Common (Translated Scientific) Name: Creosotebush / Black Grama Shrubland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This is a major upper piedmont community of the Jornada del Muerto and Tularosa basins of New Mexico and is also common in mountain drainages that occur throughout the Oscura and San Andres mountains. It has been reported from Arizona and Texas, as well. This association typically occurs at mid elevations across moderately sloped upper piedmonts and on the surrounding and slightly steeper foothill slopes (lower escarpments and dipslopes). Here, stands occur on platform summits of remnant alluvial deposits or on newly deposited colluvial sediments on the collar of foothill slopes. Soils range from loams to loamy sands with an abundance of gravel and some rocks, and are well-drained and well-developed with calcic horizons less than one meter in depth. Parent material is mixed (limestone, sandstone and igneous), and aspects are generally, but not limited to, slopes which have moderate (east- and west-facing) solar incidence. This Chihuahuan shrubland is characterized by a diverse and open shrub layer dominated by Larrea tridentata, with a well-developed grassy understory dominated by Bouteloua eriopoda. Tall-shrub phases of Prosopis glandulosa, Fouquieria splendens, and Thymophylla acerosa have been proposed. Canopies also include several other short- and tall-growing shrubs such as Gutierrezia sarothrae, Parthenium incanum, Opuntia phaeacantha, and Cylindropuntia leptocaulis. Species composition and diversity within the herbaceous layer vary from stand to stand, but grasses consistently found in the understory include Muhlenbergia porteri (under shrub canopies), Dasyochloa pulchella (found growing between Bouteloua eriopoda clumps), and Aristida purpurea. Generally, the forbs are scattered and collectively contribute little to canopy cover. Common recurrent species are Bahia absinthifolia, Menodora scabra, Echinocactus horizonthalonius, and Echinocereus triglochidiatus.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Bouteloua eriopoda in the Chihuahuan Desert is often found on uplands with gravelly sandy soils that drain easily, and Larrea tridentata''s historic distribution is also on shallow, gravelly soils (Stein and Ludwig 1979, Brown 1982a, Cornelius et al. 1991). Wondzell et al. (1987) suggested that mid-piedmont positions, which have a combination of good drainage (coarse alluvium) and good water infiltration (from sediments deposited from the uplands), support a mix of shrubs and perennial grasses. These described elements are similar to those that support stands of this association (CEGL001265) on White Sands Missile Range (Muldavin et al. 2000b). Here, stands are occasionally large (up to 40 ha [98.8 acres]), but mostly occur in a patchy distribution along upper piedmonts with ~Parthenium incanum / Bouteloua eriopoda Shrub Grassland (CEGL001734)$$ and Creosotebush/Mariola PAs (Muldavin et al. 2000b). Downslope, Bouteloua eriopoda generally fades out and gives way to other codominants such as Muhlenbergia porteri, Dasyochloa pulchella, or sparse understories. Higher on the footslopes the Larrea tridentata component fades, and occurrences grade into Dasylirion wheeleri grasslands or other grama grass alliances. Other communities in which Bouteloua eriopoda and shrubs are found together on similar coarse substrates are the Viscid Acacia/Black Grama, Tarbush/Black Grama and Mimosa/Black Grama PAs (Muldavin et al. 2000b).

Similar NVC Types: No Data Available

note: No Data Available