Assessing Mangrove Cover Change and Aboveground Carbon Stocks in Banyuglugur Using Sentinel-2, InVEST, and Field Measurements

Mangrove ecosystems play an important role in maintaining the balance of coastal environments. But in recent decades, the existence of mangroves has decreased. In the coastal area of Banyuglugur, Situbondo, mangrove rehabilitation has been carried out since 2018, but its effectiveness in changes in canopy cover and carbon stocks has not been widely studied. This study aims to analyze the changes in canopy cover and mangrove forest carbon stock in 2018 and 2025 in Banyuglugur based on satellite image analysis, to examine the relationship between canopy cover area and the amount of mangrove carbon stock, and to compare the estimation results of aboveground carbon stock derived from satellite imagery with ground measurements. The research used Google Earth Engine (GEE) and InVEST Carbon Storage and Sequestration Model software to estimate carbon storage within vegetation. Field validation was carried out through vegetation analysis using hemispherical photography. Results show a 4.12% increase in mangrove ecosystem area and a 35.83 Mg C ha-1 increase in aboveground carbon storage, based on InVEST estimates. Estimation using InVEST yields values 274% higher than direct measurements for the same carbon pools. The analysis of the relationship between canopy cover and aboveground carbon (AGC) stock showed no significant association. It can be concluded that the Banyuglugur mangrove ecosystem has experienced an increase in area and carbon stock. Correlation analysis between canopy cover and AGC shows a positive relationship (β > 0) but weak (p > 0.05). Carbon stock estimation using the InVEST model shows an overestimation compared to direct field measurements.