Abstract
General plant response to depleted uranium (DU) was tested using three widespread range‐grass species, Aristida purpurea Nutt. (purple threeawn), Buchloe dactyloides (Nutt.) Engelm. (buffalograss), and Schizachyrium scoparium (Michx.) Nash (little bluestem). Aboveground, belowground, and total biomass measures of these grasses were analyzed over the five different DU soil concentrations of 0, 50, 500, 5,000, and 25,000 mg kg‐1. Differential plant response to DU was observed between the three grasses, wiith A. purpurea and B. dactyloides exhibiting a threshold‐type response in which no changes in biomass occurred until the highest treatment level of 25,000 mg kg‐1 was reached. Schizachyrium scoparium, however, demonstrated a large degree of growth stimulation, or hormesis, at the 50 and 500 mg kg‐1 DU concentrations. Several possible mechanisms of this hormetic response are offered.
Notes
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