Species Composition, Diversity and Stand Structure of Mangroves in Olango Island Wildlife Sanctuary, Cebu, Philippines

The stand structure and species composition of the mangroves in Olango Island Wildlife Sanctuary were assessed using the following parameters: relative frequency, relative dominance, relative density, importance value, crown cover, abundance of trees/hectare, regeneration/m2 and constancy. The study recorded the presence of 17 species, 9 of which were considered rare in occurence. There was a total of 10,309 trees surveyed and O. octodonta  registered the highest with 3,739 trees , R. stylosa with 2,827 and A. marina with 1,268 as the third. The area had a very low crown cover with 23.06%. Regenerants were also very few with 1.3 wildling /sq.m2. Also, the mangroves in OIWS showed a small basal area of 1.27 m2/hectare indicating there was overharvesting/ overcutting of the trees. To prevent further degradation of the place, there is an urgency to reforest the area, with emphasis on planting the disappearing/lost species observed.