Soil salinity patterns in Tamarix invasions in the Bighorn Basin, Wyoming, USA

Saltcedar (Tamarix spp.) is an exotic, invasive shrub of riparian corridors in the western United States that can promote soil salinization via leaf exudates as Tamarix litter accumulates on the soil surface. Tamarix stands occur in association with big sagebrush (Artemisia tridentata), greasewood (Sarcobatus vermiculatus), and cottonwood (Populus deltoides) in northern Wyoming, depending on topographic position. Revegetation of Tamarix-invaded sites can be limited by altered soil conditions. Tamarix stands in northcentral Wyoming were selected to determine the relationship of Tamarix shrubs and associated vegetation to soil salinity, pH, and nutrients. In general, salinity of surface soils (0–5 cm) was greater and pH was lower than in deeper soils. Surface soils (0–5 cm) beneath Tamarix have greater salinity and lower pH than soil in interspaces. Because soil salinity in the Bighorn Basin is lower than levels documented in most Tamarix stands of the southwestern United States, many species used for revegetation should tolerate soil conditions here following Tamarix control.