Baseline Elemental Concentrations for Big Sagebrush from Western U.S.A.

Abstract

The analysis of samples of big sagebrush from 190 sites in 8 western physiographic provinces resulted in measurable concentrations of 30 elements. Except for Sb, U, and V, whose concentrations were generally below the analytical detection limits, the expected (baseline) concentration range of each element was defined. The variability in the concentration of Ba, Ca, Li, Pb, Se, Sr, and Zn among the 8 provinces was found to be nonsignificant and therefore a mean and deviation (for all provinces combined) for these elements was used to define their baseline. For concentrations of 20 of the elements (including the environmentally important metals As, Cd, Cr, Co, Cu, Hg, and Mo), significant variability was found among province populations so that baseline values are reported for each province or group of provinces. Physiographic provinces were incorporated in the study design as a convenient natural unit in presenting the element baselines and we anticipate that these data may be useful in assessing biogeochemical changes brought about by the activities of energy development, mineral processing, and other anthropogenic disturbances.