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

Mangroves are tree or shrubs growing in intertidal areas considered nowadays as protector of the coastal environment and as an economic resource. Moreover, mangroves provide regulatory functions like preventing coastal erosion, sediment stabilization, food regulation, and habitat for various animals. Despite its ecological and economic importance, the mangrove ecosystem is being destroyed at an alarming rate. Masinloc is one of the most productive coastal towns in Zambales, but it is already showing signs of degradation. In Zambales, only Subic's mangrove areas are well documented. Sazon (RMTU) and Gascon (IRNR/UPLB-CFNR) assessed the floral diversity of mangrove ecosystems in Masinloc, Zambales, from June to December 2004, to identify and characterize the remaining mangrove forests and evaluate the factors affecting the condition of mangrove ecosystems in its four barangays (Baloganon, Inhobol, San Lorenzo, and San Salvador) for conservation initiatives. Soil in San Lorenzo and Inhobol had high clay content compared to Baloganon and San Salvador which had sandy texture. This meant that only a few mangrove species thrive in Baloganon and San Salvador due to their sandy soil. Among the sites studied, San Salvador was found to possess the highest tidal level extending up to 150 cm in seaward zone and varying greatly at landward and middle zone. Variation in tidal level at each zone limits the distribution of mangrove flora in the study area. Water salinity at each study area was found suitable for mangrove growth. It was reported that mangroves thrive well in areas with salinity ranging from 10 ppt to 30 ppt. On species composition, a total of ten true mangrove species belonging to five families - Rhizophoraceae, Sonneratiacea, Avicenniaceae, Palmae, and Combretaceae - were found. The most common species found in all study sites were Sonneratia alba, Avicennia marina, Rhizophora apiculata, and R. mucronata. These species were best for replenishing the mangrove areas. On population density Inhobol showed the highest population density (2202 trees/ha) followed closely by San Lorenzo (2032 trees/ha) and Baloganon (1200 trees/ha) San Salvador was sparsely populated registering a density of only about 1033 trees/ha. Brgy. Inhobol should be given the utmost priority in conservation since it possessed the highest mangrove floral diversity. However, the other areas should also be protected through formal regulations and introduction of wise pattern of mangrove resource use. From the results, the study recommends the development of a comprehensive management plan for mangrove protection and conservation to save the remaining forests from further destruction. Stakeholders/resource users should also be educated on the potential ecological and economic benefits of conserving mangroves. Strict implementation of ordinance and formal regulations to deter further clearing of mangrove trees should be enforced and lobbied for. Likewise, the use of destructive methods such as 'Sayudsod' for crab/shrimp catching should be banned. A community-based mangrove management should be introduced to empower the community in managing resources which benefit them. And lastly, a conservation and protection plan to effectively manage the remaining tree stands should be formulated.