Vulnerability analysis and sustainable rehabilitation strategies for mangrove ecosystems in Bedono coastal area, Central Java.

Abstract

Mangrove ecosystems in Bedono Village, Demak Regency, Central Java, are seriously degraded due to aggressive coastal abrasion, extreme soil salinity (45‰-80‰), and failure of previous rehabilitation programmes. This study aims to assess the level of vulnerability of mangrove habitat and formulate an integrated rehabilitation strategy that includes ecological and institutional aspects. Data were collected through tidal analysis, measurement of sediment texture and soil salinity, identification of plankton and macrobenthos diversity, and analysis of mangrove species community structure. The Coastal Vulnerability Index (CVI) was calculated based on four biophysical parameters, namely tidal inundation duration, maximum inundation height, soil salinity, and substrate type. Spatial analysis was conducted using ArcGIS 10 software to map the zones with high vulnerability. In addition, the Analytical Network Process (ANP) approach was used to prioritise ecological and institutional problems and develop solutions based on stakeholder interviews and expert validation. The results showed that the mangrove ecosystem in Bedono is highly vulnerable, with tidal inundation for 29-31 days per month, an average inundation height of 0.97 m, and a dominance of loamy sand textured soil. Avicennia marina species dominated in all growth stages, while the diversity of other species was very low. Key problems identified include coastal abrasion, low planting success rates due to non-adaptive techniques, and weak coordination between stakeholders. Priority solutions include installation of sediment traps, implementation of adaptive planting techniques, community involvement in monitoring, and establishment of village regulations to support programme sustainability. This study provides a new framework for integrating CVI-based ecological vulnerability mapping and institutional analysis to support comprehensive mangrove rehabilitation planning in heavily impacted coastal areas.