The infrequency with which this species was encountered was particularly noteworthy because Atriplex spinifera is said to have once been representative of large areas of the western San Joaquin Valley (Piemeisel & Lawson 1937).

Indeed, the Tranquillity Demonstration Site (red dot) falls within the one of the broadest expanses of the “spiny saltbush zone.” The near absence of this species in the areas around the study site speaks strongly to the magnitude of the changes to which the San Joaquin Valley has been subjected.