XVI International Botanical Congess

Sea-level rise will flood coastal areas and affected woody species based on flood and salinity tolerances. Four patterns of photosynthesis (A) were seen in experiments with fresh and saltwater flooding. Freshwater flooding of Taxodium distichum and Cephalanthus occidentalis did not reduce A. Nyssa aquatica and Fraxinus pennsylvanica had initially reduced A, but no lasting effect. For Quercus lyrata, Q. nigra, Q. nuttallii, and Sapium sebiferum, A was unaffected for 2 weeks, but decreased thereafter. For N. sylvatica var. biflora and Q. michauxii, A was negatively related to time of flooding. When flooded with 2 ppt salinity, the relative species responses did not differ, and A was reduced for all species. Coastal flooding with small salinity increases will affect A, based on relative flood tolerances.