Floral diversity assessment of mangrove ecosystems in Masinloc, Zambales [Philippines]

The study was conducted to assess the floral diversity of the remaining mangrove forests in the four coastal barangays [villages] of Masinloc, Zambales. The factors that contributed to the present state of mangrove ecosystems were likewise evaluated. Three 10x10 m quadrats were located in each study site. The species composition and the floral diversity of each mangrove ecosystem were analyzed and compared using the following indices: Shannon-Weiner Index of Diversity (SHDI), Shannon-Weiner Index of Evenness (SHEI) and Simpson's Index of Dominance. Two major mangrove species belonging to five families of Rhizophoraceae, Sonneratiacea, Avicehniaceae, Palmae and Combretaseae, four minor components and six mangrove associates were identified. Sonneratia alba, Avicennia marina, Rhizophora apiculata and R.mucronata were the species common in all sites. Among the sites studied, Brgy. Inhobol was the most diverse in terms of mangrove floral composition attaining on SHDI of 0.97. The remaining mangrove forests in Masinloc are still in healthy state but comprise mainly of young mangrove vegetations. Most species were within the diameter range of 4.1-20.0 cm. S. alba was the only species representing all diameter class attaining a diameter at breast height (dbh) of more than 40 cm. Various stakeholders valued mangroves in terms of their resource and regulatory functions. Several factors, however threatened the condition of mangroves forests in Masinloc, such as the use of sayudsod, crab harvesting by soil digging, water pollution, coastal development, squatting, continued fishpond development and lack of formal regulations. Brgy. Inhobol should be given utmost priority in conservation since it possessed the highest mangrove floral diversity. Other areas like San Lorenzo, Baloganon and San Salvador should likewise be protected through formal regulations and introduction of wise pattern of mangrove ecosystem in Masinloc, Zambales. Identified thriving mangrove species can be propagated for reforestation purposes. It was recommended in the study that a comprehensive community based mangrove ecosystem management scheme be implemented to rehabilitate and conserve the remaining mangrove stands.