Monitoring of Black Mangrove Restoration with Nursery-Reared Seedlings on an Arid Coastal Lagoon

background

This paper describes a reforestation experiment with black mangrove (Avicennia germinans) in an arid mangrove forest of Baja California Sur, Mexico. In arid mangrove systems, natural regeneration and small-scale reforestation are not adequate to restore mangrove forests, as they may be in the humid tropics. Thus, alternative nursery techniques for arid mangroves must be developed.

Research Goals & Methods

The authors collected black mangrove propagules from the field and grew seedlings in a terrestrial nursery for 3 months. Propagules were planted in plastic biodegradable bags in a sand and salt mixture, incubated indoors for 1 week, and then transferred to an outdoor nursery.  Survival rate in the nursery was 100%. The seedlings were subsequently transplanted to a clear-cut black mangrove swamp in 5 plant clusters and were monitored every 6 months for 2 years. Survival rate was 74% after 24 months.

Conclusions & Takeaways

Mangroves achieved maximum growth in two-plant clusters. Natural regeneration in the experimental lagoon and in arid mangroves in general is very low, thus, planting of terrestrial nursery-reared mangroves provides a good option for restoration. Direct planting and tidal zone nursery rearing have proved unsuccessful for arid mangrove systems.