Pivovaroff, A.L.; Swift, C.; Battaglia, L.L.; Kunz, B.; Platt, W.J., and Yoder, C.L., 2015. Physiological profiles as indicators of response to hurricane disturbance for three coastal wetland species.

Hurricanes alter light and water availability via canopy damage and storm surge delivery and are expected to intensify with climate change. Plant species respond to environmental changes by making physiological adjustments in situ or through distribution changes. Three years after Hurricane Katrina, we compared functional traits and water relations among three species along the coenocline at Weeks Bay National Estuarine Research Reserve, Fairhope, Alabama, U.S.A. Based on posthurricane distribution changes for these species, we hypothesized that (1) Cladium mariscus, whose distribution expanded slightly, is responsive to increased light availability in the disturbed forest at the landward end but is strongly limited by water stress at its seaward edge; (2) Baccharis halimifolia, whose distribution shifted and abundance increased posthurricane, is responsive to increased light availability, cannot tolerate very low light levels or water logged soils, but can tolerate moderate salinity; and (3) Morella cerifera, whose distribution remained unchanged, would show little or no difference in measured functional traits and water relations at its landward vs. seaward edges. Cladium mariscus showed decreased water potential (Ψ) at its seaward edge, but leaf mass per area (LMA) did not vary as forest cover increased landward. Baccharis halimifolia exhibited lowest LMA and highest Ψ in the middle of its distribution, but was least vulnerable to cavitation (Ψ₅₀) with increased forest cover. Morella cerifera exhibited no difference in water stress, wood density, or Ψ₅₀ across its distribution. Our results suggest differences in physiological response to light availability and water stress may affect the postdisturbance distribution of plant species and influence changes in distribution of species exposed to chronic sea level rise.