Physiological Response to Salinity by Four Salt Marsh Plants

Salt marsh–atmosphere exchange of energy, water vapor, and carbon dioxide: Effects of tidal flooding and biophysical controls

“…Low soil moisture, often invoked to explain low α ′ values, did not occur in our salt marsh. Although salt‐induced salt marsh water stress has been hypothesized, salt marsh plant species are generally well enough adapted to the saline environment to avoid physiological drought [ Kuramoto and Brest , 1979; Drake , 1989]. Our calibrated α ′ values were similar to those reported by German [2000] for the Florida Everglades.…”

Salicornia L. (Salicornia pusilla J. Woods, S. ramosissima J. Woods, S. europaea L., S. obscura P.W. Ball & Tutin, S. nitens P.W. Ball & Tutin, S. fragilis P.W. Ball & Tutin and S. dolichostachya Moss)

“…Langlois (1968a) recorded solute (osmotic) potentials no lower than −2.67 MPa for S. europaea in the Orne estuary. Material from a coastal salt marsh at Seal Beach, California had a water potential (ψ w ) of −4.23 ± 0.24 MPa, with a component solute potential (ψ s ) of −5.32 ± 0.10 MPa (Kuramoto & Brest 1979). Tsuda (1961) reported an extreme solute potential of expressed sap as −7.6 MPa, with sodium chloride content contributing −7.2 MPa of this, under extremely hypersaline conditions in Japan.…”

“…rubra ), with less negative values at higher salinity reflecting differences in long‐term water‐use efficiency. Low activities of PEP carboxylase, without fluctuations due to endogenous rhythms, have been reported (Kuramoto & Brest 1979). Net photosynthetic rates have been shown to decrease slowly with lowering of external water potential; CO 2 uptake in the absence of salt was 7.59 ± 0.64 mg dm −2 h −1 on a leaf area basis (14.22 ± 1.66 mg g −1 h −1 on a dry mass basis) and this was reduced to 4.75 ± 0.12 mg dm −2 h −1 (8.47 ± 1.30 mg g −1 h −1 ) after equilibration for 72 h at seawater salinity (Kuramoto & Brest 1979).…”

Carbon Dioxide Assimilation, Photosynthetic Efficiency, and Respiration of a Chesapeake Bay Salt Marsh

“…Kuramoto & Brest (1979) report that photosynthesis in Spartina foliosa and Distichlis spicata is reduced by growth in, or exposure to, low water potential. In high light flux, however, S. alterniflora did not lose its photosynthetic capacity, even when grown in water as saline as sea water (Longstreth & Strain 1977).…”