Assessment of mangrove species composition and diversity in selected coastal Barangays in Pangutaran Island, Sulu Province, Philippines

Abstract

Mangrove forests provide nature-based solutions, serving as crucial coastal defenses against natural disasters and as nurseries for marine organisms. Despite its ecological and economic importance, there is still a lack of baseline information on the species composition and diversity of Pangutaran Island's mangrove forest. It is also often marginalized, largely due to limited community understanding. The absence of localized baseline data makes it difficult to assess its biodiversity status, detect environmental degradation, or implement evidence-based policies for sustainable coastal resource management. Therefore, this study aims to determine the species composition and diversity within three selected barangays, providing the empirical foundation needed for informed conservation and policy strategies. Three 100-m transect lines were established perpendicular to the shoreline with five 10x10m quadrats. The study recorded 6 species across three families. Species diversity at the three sampling sites was low (H’ = 0.65-1.47), dominated by Rhizophoraceae. The evenness values across the three sites range from 0.3837 to 0.8671, indicating a species distribution considered semi-balanced to almost balanced. The low diversity across sites, with a dominance of small, sapling-aged trees, is likely driven by the rampant anthropogenic activity associated with resource extraction. These findings highlight the pressing need for sustainable conservation efforts. As a result, this study provides essential baseline data necessary to design effective coastal management plans aimed at protecting the ecological health of mangrove forests, specifically within the Sulu region.