Grama (Bouteloua Lag.) Communities in a Southeastern Arizona Grassland

Nicholson, Robert; Bonham, Charles

Fifty stands, representing six common and three rare species of gramas (Genus Bouteloua), were sampled for vegetation abundance, species composition, and selected habitat factors. Numerical and statistical procedures were used to aid in obtaining succinct descriptions of the habitat structure of the grama species. Factors such as texture and content of various nutrients of soils were among those that showed trends. Black grama (B. eriopoda) was found to be associated with soils higher in nitrate, potassium, organic matter, pH, and lime. Most similar to stands of black grama (B. curtipendula), which tended to also be associated with sandy clay textured soils and steep, rocky slopes. All stands of eludens grama were found on southernly exposures. Hairy grama (B. hirsuta) and spruce-top (B. chondrosiodes) were most widely distributed and tended to occur together on relatively level sites with clayey, acidic soils. Curly mesquite (Hilaria belangeri) was nearly always associated with these two gramas. Blue grama (B. gracilis) tended to be most abundant on acidic, relatively infertile, sandy clay loam soils.

Grama (Bouteloua Lag.) Communities in a Southeastern Arizona Grassland

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