Background:

Radial oxygen release by wetland plants is a process that creates aerobic conditions in the sediment that enhance aerobic microbial activity. Such activity has a big impact on wetland environmental services. Little is known about radial oxygen release by native macrophytes of tropical wetlands.

Study site:

Veracruz, Mexico

Research Questions:

Which of the most abundant native macrophytes from tropical wetlands have the higher radial oxygen release? What is the effect of hydrological conditions on radial oxygen release of the most abundant native wetlands plants of tropical wetlands?

Methods:

Root production, root porosity and Oxygen radial release were measured in 7 native macrophytes of tropical wetlands in Veracruz. The macrophytes were grown under three hydrological conditions: capillarity, saturation and flooding.

Results:

The species that produced more weight and volume of root (Pontederia Sagittata, Sagitaria lancifolia y Thalia geniculata) showed low radial oxygen released base on dry weight. Under flooding conditions, radial oxygen release per plant showed significant differences between the species, being Typha dominguensis the specie with the highest oxygen radial release (148 ± 46 µmol O2 d−1) and Leersia ligularis the plant with the lowest radial oxygen release (22 ± 46 µmol O2 d−1).

Conclusion:

Flooding conditions decreased root volume and weight of native macrophytes from Veracruz wetlands, also increased root porosity and in general stimulated higher radial oxygen release per plant, with significant differences among the studied plants, indicating that radial oxygen release depend of plant phenological characteristics and the hydrological conditions.

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