A framework for the quantitative assessment of mangrove resilience

Resilience in coastal areas has been recognized as a core requirement to sustainable coastal management in the last decade, and coastal ecosystems are providers of valuable services and resources. Mangroves are important for coastal protection, from waves and during storms, particularly from the destructive winds and storm surge associated with typhoons or cyclones. Mangroves have high rates of tree and plant growth, and waterlogged soils slow decomposition, resulting in long-term carbon storage. With an estimated global mangrove area of 137,760 square kilometers, carbon sink values are appreciable. However, despite these values that mangroves provide, the worldwide mangrove area has been coarsely estimated to have reduced by more than 50% relative to what it was just over a century ago, owing to direct human impacts. Human stressors on mangroves include forest logging, coastal land use change, coastal engineering, conversion to aquaculture, pollutant inputs, and mining.

Climate change is adding more pressures on mangroves. Global greenhouse gas emissions have set a record high this century, leading to adverse effects on the environment. Rising sea levels due to steric effects and melting of glaciers and ice caps have caused increased flooding, coastal erosion, and saltwater intrusion. Future projections are of increased sea level rise rates, which will have impacts on mangroves. Owing to sea level rise and net substrate accretion not keeping up, mangroves of the Southeast Asia/West Pacific region have risk of loss by the end of this century.

Mangrove forest management and rehabilitation is imperative, with potential climate change threats to their sustainability increasingly identified . Mangroves have suffered major losses in the last century and future impacts will continue without directed management to increase mangrove system resilience.