Delayed modifications in plant-water relations in the coastal marsh halophyte Spartina patens following sudden increases in soil salinity

Abstract

Abstract Little is known about how upper marsh plants (growing in freshwater) will respond physiologically to sudden increases in salinity. In this study, we used experimental microcosms to evaluate changes in plant-water relations in the halophyte Spartina patens following increases in soil salinity (salinity levels: 15, 30, and 45). There was a delay (by 3–5 weeks) in the lowering of leaf water potential (ψleaf), stomatal conductance (g), and tissue water content (θ) in plants subjected to salinities of 30–45. These physiological delays in plant-water adjustments following sudden increases in salinity may be an adaptation of S. patens that allows it to effectively exploit higher habitat elevations that receive intermittent seawater inundations without promoting costly physiological modifications.