Conventional reforestation versus assisted regeneration: Comparative effectiveness of two mangrove restoration methods on Sainte-Marie Island, Madagascar

This study compares two mangrove restoration methods on Sainte-Marie Island, Madagascar: conventional reforestation and assisted regeneration. After 10 months of monitoring, initiated three months after planting, assisted regeneration (85%) showed a higher survival rate compared to conventional reforestation (72%). Optimized edaphic and hydrological conditions explain this difference. Analysis of environmental parameters demonstrates the importance of controlled salinity and muddy soils. Community involvement is crucial to the sustainability of interventions. These results, combined with 50% lower costs for assisted regeneration, offer promising perspectives for sustainable mangrove restoration strategies in the face of climate change challenges. However, this period is considered too short to monitor plots undergoing restoration. While instructive, it is insufficient to assess the full ecological trajectory of the restoration. Mangrove may take 5 to 10 years to reach ecological stability. Stochastic events such as cyclones, which are frequent in the region, could significantly alter the trend observed.