Quantifying Decadal Recovery in Small Scale Community-Based Mangrove Management (SSCM) in East Java, Indonesia, using Integrated Remote Sensing and Ecological Assessments

This study examines ecological outcomes of small-scale community-based mangrove management (SSCM) in three locations in East Java: Clungup Mangrove Conservation (CMC, south coast), Penunggul (north coast) and Hijau Daun (small island). The primary objective is to evaluate the impacts of local community initiatives on mangrove ecosystem recovery over the past decade. Methodology combined remote sensing and field-based approaches. Machine learning google earth engine (GEE) was applied to assess past decade vegetation recovery using Normalized Difference Vegetation Index (NDVI), while raster analysis processed using R software to obtain net value change. To ensure compatibility between datasets, spatial harmonization was performed by resampling and aligning Sentinel-2 imagery to match Landsat 7 resolution using QGIS software. Field observations were conducted to assess the current ecological metrics, and descriptive analysis was carried out to connect restoration outcomes with management practices. Research findings indicate notable increases in net value change, with CMC showing the most substantial recovery (0.2-0.3), shifted from predominantly open or sparse areas to moderate or dense vegetation. Mangrove in Daun and Penunggul have ΔNDVI of 0-0.1, reflecting mild improvement in vegetation cover. Ecological assessments further revealed variation among sites. In Penunggul, diameter at breast height (DBH) of mangrove ranged from 2-16 cm (mean 7.70±3.34 cm), with average tree density of 2,300 ind/ha. CMC has mangrove density from 1,200-3,600 ind/ha and mean DBH 5.70±2.20 cm (range from 3.00-10.00 cm). Hijau Daun exhibited the lowest average density at 1,333 ind/ha, with DBH range from 2.00-37.00 cm (mean 9.27±7.24 cm).