Evapotranspiration from riparian vegetation: Water relations and irrecoverable losses for saltcedar

Evapotranspiration (ET) from saltcedar (Tamarix chinensis Lour) varies with weather factors as well as with stand density and water availability. In California, ET in July for a unit ground area of saltcedar in large drums varied from 2 millimeters per day in sparse stands, to 16 millimeters per day in dense stands; ET declined and diffusive resistance increased when saltcedar plants were subjected to stress brought on by low soil water availability and/or high evaporative demand. In a natural salt-cedar stand in New Mexico, ET in June varied from 3 millimeters to 11 millimeters per day, depending upon weather and plant density. Extrapolation of experimental transpiration data to field sites must, therefore, be done carefully when assessing irrecoverable ET losses.