Abstract:
Regular monitoring of mangrove forests is important to mitigate the rapid decline of this
ecosystem. Thus, this study seeks to assess the present status of the mangroves in Kitay,
Tagkawayan, Quezon Province by comparing it with a previous study of the site conducted in
1999. Using four belt transects with a cumulative area of 3000 m2, nine true mangrove species
were identified, namely Aegiceras floridum, Aviceimia officinalis, Bntguiera cylindrica, Bruguiera
gymnorrhiza, Camptostemon philippinense, Osbomia octodonta, Rhizophora apiculata,
Rhizophora mucronata, and Sonneratia alba. Using quantitative measurements of population, S.
alba was the most important species. The scatterplot diagrams showed distinct zonation patterns
dominated by 5. alba and A. officinalis on the seaward and middleward while R mucronata on the
landward fringe. Regeneration of the wildlings was high at 1,543 wildlings/ha. Productivity was low, registering a leaf area index of 1.54 and a net primary productivity of 20,005 tons/ha/yr. Comparing this with the 1999 study, 5. alba remained the most important species, O. octodonta
remained the species with the highest regeneration/ha, and the Shannon-Wiener biodiversity index
(H) was 2.04 as compared to H=2.59 in 1999, meaning diversity decreased. Human disturbances
are apparently the main contributions to loss of diversity. The study emphasizes that much efforts
be undertaken to conserve and manage the remaining mangrove stands.
