Assessing Diversity, Carbon Stock Quantification and Economic Valuation of Mangrove Forest along the Coastal Areas of Davao Oriental, Philippines

This study assessed the diversity, aboveground carbon stock, and economic value of mangrove forests along the coastal areas of Davao Oriental, Philippines. Field-based mangrove inventories were conducted using three 100-m transects comprising 20 plots and a total sampled area of 2000 m². The sampling was intended to characterize the mangrove community at the assessed field sites and is not treated as statistically representative of all mangrove forests in the province. Remote sensing using the Mangrove Vegetation Index (MVI) and Landsat 8 imagery was used to delineate mangrove extent. The mangrove community comprised seven species and had a Shannon–Wiener diversity index (H′) of 1.65 and Pielou’s evenness index (J′) of 0.85, indicating moderate diversity and relatively high evenness. Sonneratia alba was the most abundant and structurally dominant species and contributed 12,908.43 kg (88.86%) of the estimated 14,524.63 kg aboveground carbon stock in the sampled plots. The current GIS output indicates a total mapped mangrove extent of 3065.82 ha; however, municipal-level values require verification against the original GIS zonal-statistics output before publication. The field-based carbon estimate was not extrapolated to the remotely sensed provincial extent. Using an assumed conservative carbon-market scenario of US$5 tCO2e⁻¹ and a social-cost scenario of US$51 tCO2e⁻¹, the sampled carbon stock was valued at US$266.45 and US$2717.79, respectively. The findings highlight the ecological and socioeconomic importance of mangroves for biodiversity conservation, carbon storage, fisheries, coastal protection, and local livelihood support.