Influence of newly imposed salinity and waterlogging on Eucalyptus gracilis in South Australia.

We investigated the effects of waterlogging and salinity on the water relations of Eucalyptus gracilis F. Muell. growing within the Stockyard Plain Disposal Basin Reserve, 15 km southwest of Waikerie, South Australia. Presence and depth of the saline groundwater had relatively little effect on the water relations of the trees even when large differences in tree health were visible. Predawn water potential, stomatal conductance, and foliar sodium and potassium concentrations were similar for all individuals independent of the depth and salinity of the groundwater. As expected, the severity of water stress increased over summer when predawn water potentials became progressively more negative and foliar salt concentrations increased. These changes occurred in all plants independent of depth or salinity of the groundwater.