Wetland Plant Morphology

Abstract

Anaerobic conditions cause death in plants grown in saturated soils. Where flooding is predictable, species may time germination to coincide with low water levels. In other areas, specialized adaptations, such as rapid shoot elongation, adventitious root production, or shoot buttressing and fluting, are strategies to counteract oxygen depletion. Aerenchyma in shoots and roots allow oxygen to move from emergent to submerged organs and may diffuse out of roots oxidizing surrounding soils. Temperature gradients drive pressurized air movement within some plants. Shallow, extensive, intertwining roots can improve oxygen penetration and provide a belowground network, limiting hurricane damage. Prop roots and pneumatophores enhance oxygen movement in some mangrove plants. Floating mats are produced in areas experiencing subsidence. Solute imbalances can create conditions where water leaves the cytoplasm. Water loss can be prevented by production of salt barriers and nontoxic solutes in saline conditions, but also by confining CO₂ production to night time.