Long-term monitoring of mangrove restoration and carbon dynamics in Tanjung Benoa, Bali, Indonesia: An assessment approach using combination remote sensing and field surveys

Abstract This study investigated the long-term dynamics of mangrove ecosystems in Tanjung Benoa, Bali, Indonesia, from 1990 to 2024. The research aimed to evaluate the efficacy of restoration efforts and quantify changes in mangrove extent, health, biomass, and carbon stocks. Employing a time-series analysis of Landsat imagery alongside field assessments conducted in 1994, 2019, and 2024, we examined the long-term dynamics of mangrove ecosystems. The research aimed to assess the effectiveness of restoration efforts and quantify changes in mangrove extent, health, biomass, and carbon stocks. We utilized a time-series analysis of Landsat imagery and conducted field assessments in 1994, 2019, and 2024 to differentiate between natural and restored mangroves using image classification techniques. Mangrove health was evaluated using the Normalized Difference Vegetation Index (NDVI), and we directly measured biomass and carbon stocks in 30 field plots distributed across three transects. A random forest regression model was developed to predict multi-temporal carbon stocks based on NDVI values for both mangrove types. The findings revealed a significant positive trend in mangrove area, with an average annual increase of 2.15%. Restored mangroves accounted for 78.9% of this expansion. NDVI analysis showed improvements in overall mangrove health and vegetation cover. A strong positive correlation was found between NDVI and carbon stock (R² = 0.730), and the random forest model demonstrated strong predictive capabilities for carbon storage (R² = 0.807). These results highlight the effectiveness of mangrove restoration initiatives and the importance of ongoing monitoring to inform conservation strategies. The dataset generated, detailing carbon stocks in both restored and natural mangrove areas, is a valuable resource for the blue carbon research community and policymakers. It offers essential insights for climate change mitigation and coastal resilience planning. This integrated monitoring approach aligns with blue carbon policy frameworks and supports Indonesia's climate mitigation and coastal resilience commitments. The study also opens up exciting possibilities for future research and collaboration, inspiring and motivating the audience to continue the work.