Chihuahuan - Sonoran Desert Bottomland and Swale Grassland

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Nature Serve ID: CES302.746


Typically on Quaternary alluvium, but may be local in nature and mapped within various geological formations.


Generally found on local topographic lows that may be associated with a drainage or may occur as basins or swales.


Found on tight soils, typically Clay Flat Ecological Sites.

Parent Description

This system is named based on the regions (Chihuahuan and Sonoran Deserts) where it is best developed and occupies significant areas, however it does occur well outside these regions, at least as far north and east as the Rolling Plains of Texas. The system typically occurs in local topographic lows that may be associated with drainages, or may represent swales or basins, but typically receives run-off from the surrounding landscape. Soils are generally clayey, and in some cases the shrink-swell characteristics of the soil may limit the development of woody species. Pleuraphis mutica (tobosa) is generally the clear dominant, though other species such as Panicum obtusum (vine-mesquite), Sporobolus airoides (alkali sacaton), and Pascopyrum smithii (western wheatgrass) may be present. Prosopis glandulosa (mesquite) may be present, and in some cases may develop into a significant canopy. The system often occupies the Clay Flat Ecological Site.

Ecological Mapping Systems