Aeolian dust in a saline playa environment, Nevada, USA

Saline playas in north-western Nevada, U.S.A., remnants of pluvial periods of the Pleistocene, represent a tremendous source of unconsolidated sedimen ts available for aeolian transport. This study investigated the transport o f aqueous-soluble solutes in dust from July 1994 through June 1996 along a transect from a barren salt-encrusted playa surface (elevation = 1224 m), t o a former pluvial lake beach (elevation = 1228 m), to a dune-mantled uplan d (elevation = 1248 m). The content of aqueous-soluble solutes in aeolian d ust showed a significant (p less than or equal to 0.05) interaction with du st trap location (playa, beach, dune) and time of collection. Dust collecto rs on the playa surface generally contained significantly more aqueous-solu ble solutes and had greater total flux of solutes than either the beach or the dune locations. The solute content of aeolian dust was usually higher, in some cases several orders of magnitude, than chat in the surface 5 cm of soil. Recent changes in playa hydrology may explain this result. Pulses of nitrate-rich dust, synchronous with spring emergence, and other nutrient a dditions via aeolian dust may have stimulated invasion of dune-mantled upla nds by the weed Salsola paulsenii (barb-wire Russian thistle). (C) 1999 Aca demic Press.