Name:
Bouteloua gracilis Herbaceous Alliance
Reference:
Western Ecology Working Group of...
Description:
This widespread alliance includes grasslands dominated or codominated by Bouteloua gracilis, and is found across the Great Plains from near the United States-Mexico border to southern Canada. The bulk of this alliance occurs in the western Great Plains and southwestern United States, but one extensive and one restricted community occur in the midwestern United States. Stands are found on flat to rolling uplands such as plains, plateaus, foothills, valley bottoms, and sand sheets and dunes with a variety of soil types. Surface soils can range from sandy loam to loamy clay. Subsoils are often finer than the surface soils and may be somewhat impermeable to water. The upland position and heavy soils often result in much of the precipitation running off, and drought conditions prevail for much of the year. This trend is more pronounced in the northern part of this alliance. In the southern portions of its range, the greater temperatures and lack of precipitation allow this shortgrass alliance to occur on coarser soils. Vegetation within this alliance is dominated by short grasses with mid grasses present to codominant. Mid grasses are more abundant in the eastern portions of this alliance. Coverage by short grasses is moderate to almost complete. The foliage is typically 7-19 cm tall with flowering stalks reaching 45 cm. Midgrass species are usually dwarfed because of dry conditions and may not exceed 0.7 m except in especially wet years. Shrubs are very rare except in the southern parts of this alliance's range where scattered desert shrubs may occur (<10% cover). Typical codominant species are Buchloe dactyloides or Pleuraphis jamesii (= Hilaria jamesii). Other common to codominant graminoids may include Aristida purpurea, Bouteloua curtipendula, Bouteloua hirsuta, Carex filifolia, Carex inops ssp. heliophila, Carex duriuscula (= Carex eleocharis), Elymus elymoides, Hesperostipa neomexicana (= Stipa neomexicana), Pascopyrum smithii, Sporobolus cryptandrus, or Sporobolus airoides. There are a variety of forbs found in stands of this alliance, although they do not contribute greatly to the total vegetation cover. Common forbs include Astragalus spp., Gaura coccinea, Machaeranthera pinnatifida var. pinnatifida, Opuntia polyacantha, Plantago patagonica, Psoralidium tenuiflorum, Ratibida columnifera, and Sphaeralcea coccinea.
Accession Code:
VB.CC.18707.BOUTELOUAGRACIL
Plot-observations of this Community Concept:
0
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