Apacherian-Chihuahuan Semi-Desert Grassland and Steppe

Geology

Occurs on various substrates, typically not occupying fine alluvium, but may occur on alluvial outwash slopes. This system may occur on igneous, limestone, and sandstone.

Landform

At lower elevations on mountain slopes and continuing onto lower bajadas.

Soils

Typically on rocky soils derived from limestone, igneous, and sandstone substrates.

Parent Description

This grassland system sometimes occurs in association with Chihuahuan Mixed Desert and Thornscrub and may have shrubs of that system present. The herbaceous layer may be dense, but typically much bare ground or rock is visible. Graminoids dominate the layer with species such as Bouteloua eriopoda (black grama), Bouteloua curtipendula (sideoats grama), Muhlenbergia setifolia (curlyleaf muhly), Bouteloua ramosa (chino grama), Muhlenbergia porteri (bush muhly), Bouteloua barbata (sixweeks grama), Dasyochloa pulchella (fluffgrass), Digitaria californica (Arizona cottontop), and Aristida spp. (threeawns). On some slopes, species such as Dasylirion leiophyllum (smooth sotol), Nolina texana (Texas sacahuista), Opuntia engelmannii (Engelmann pricklypear), Agave lechuguilla (lechuguilla), Yucca torreyi (Torrey’s yucca) and/or Fouquieria splendens (ocotillo) may be conspicuous, though scattered elements. Nolina spp. (sacahuista) and Dasylirion spp. (sotol) may dominate some sites, especially on limestone slopes. If significant areas dominated by shrubs are encountered, these sites are likely mapped as Chihuahuan Mixed Desert and Thornscrub, Chihuahuan Succulent Desert Scrub, or Chihuahuan Creosotebush Desert Scrub depending on composition. Shrub species that may be encountered in these grasslands include Larrea tridentata (creosotebush), Parthenium incanum (mariola), Viguiera stenoloba (skeleton-leaf golden eye), Acacia constricta (whitethorn acacia), Mimosa aculeaticarpa var. biuncifera (catclaw mimosa), Condalia ericoides (javelina bush), and many others.