2024/12/16 by Adriano Losso, Alice Gauthey, Stefan Mayr +1 · 1 voice
Agricultural and Biological Sciences · Environmental Science · #Coastal wetland ecosystem dynamics #Plant Stress Responses and Tolerance #Plant responses to water stress
paper · pdf · doi:10.1111/pce.15332
openalex publication_date 2024/12/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Mangroves are highly salt-tolerant species, which live in saline intertidal environments, but rely on alternative, less saline water to maintain hydraulic integrity and plant productivity. Foliar water uptake (FWU) is thought to assist in hydration of mangroves, particularly during periods of acute water deficit. We investigated the dynamics of FWU in Avicennia marina and Aegiceras corniculatum by submerging and spraying excised branches and measuring leaf water potential (Ψ) at different time intervals. Daily changes in xylem sap composition (ionic concentrations, pH and surface tension) were monitored during 2 days characterised by the presence of morning dew and difference in tides. In both species, FWU occurred over relatively short times, with leaf Ψ recovering from -4.5 MPa to about -1.5 MPa in 120-150 min. At predawn, Ψ was higher (-1.5 MPa) than sea water Ψ, indicating that leaves had been partially rehydrated by absorbed dew. Tides did not affect Ψ, but high tides increased the overall ionic content of xylem sap. The results indicated mangroves are extremely efficient in absorbing non-saline water via the leaves and restoring the water balance to Ψ higher than seawater. Changes in xylem sap composition, which were strongly influenced by tides, were not affected by observed FWU.