Using Melaleuca Fences as Soft Coastal Engineering for Mangrove Restoration in Kien Giang, Vietnam

Background

This study examines the installation of two fence designs made from Melaleuca poles along coastal fringe mangroves to attenuate wave action and promote accretion of sediments in Southwest coastal Vietnam.

Conclusions & Takeaways

Installing “wave barrier fences” and “silt-trapping fences” resulted in the accumulation of 44 and 42 cm of soil over 3 years, respectively, which was significantly different from the 0.3 cm accumulation of soil at the unfenced control site. Heavy soil accumulation occurred during the wet season at both of the fenced sites as well as the unfenced control site; however, all accumulation at the unfenced site was washed away during the last month of the wet season. Planted Avicennia alba seedlings had substantially higher survival rates (44% and 62%) than planted Rhizophora apiculata seedlings (14% and 35%) behind the wave-barrier and silt-trap fences. Natural regeneration of Avicennia alba seedlings began 1.5 years after fence installation for both fence types, but was substantially higher behind the silt-trap fence design (reaching densities of 7,100 trees/ha) than the wave-barrier fence (2,400 trees/ha).