North American Warm Desert Lower Montane Riparian Woodland

Geology

Various geological formations associated with the mountains of the Trans-Pecos, including limestones, sandstones, igneous formations, and alluvial and colluvial deposits.

Landform

Drainages on lower mountain slopes.

Soils

Various soils and sometimes rocky sites lacking any soil development.

Parent Description

This system occupies valleys, drainages, and canyons of lower mountain slopes and foothills. These linear woodlands follow perennial and seasonally intermittent streams and may occur as woodlands or shrublands. Woody species that may be dominant include Populus fremontii (Arizona cottonwood), Populus deltoides ssp. wislizeni (Rio Grande cottonwood), Juglans major (Arizona walnut), Fraxinus velutina (velvet ash), Salix gooddingii (southwestern black willow), Juglans microcarpa (little walnut), Sapindus saponaria var. drummondii (western soapberry), Ungnadia speciosa (Mexican buckeye), and Celtis laevigata var. reticulata (netleaf hackberry). Shrubs may be present in the understory or may form shrublands lacking an overstory canopy or with a sparse emergent canopy. Shrubs commonly encountered include Baccharis salicifolia (seepwillow), Salix gooddingii (Southwestern black willow), Fallugia paradoxa (Apache plume), Rhus microphylla (littleleaf sumac), Cephalanthus occidentalis (common buttonbush), Mimosa aculeaticarpa var. biuncifera (catclaw mimosa), Acacia constricta (whitethorn acacia), Brickellia californica (California brickellbush), Prosopis glandulosa (honey mesquite), and Acacia greggii (catclaw). Some sites with sparse woody overstory may be dominated by grasses such as Bouteloua curtipendula (sideoats grama), Muhlenbergia porteri (bush muhly), Distichlis spicata (saltgrass), Muhlenbergia rigens (deergrass), Sporobolus airoides (alkali sacaton), Pleuraphis mutica (tobosa), Bothriochloa laguroides ssp. torreyana (silver bluestem), Bouteloua gracilis (blue grama), and Aristida spp. (threeawns).