Mangrove structure, composition, and distribution through restoration of Indonesia’s mangrove: A systematic review

Mangrove forests are critical coastal ecosystems in tidal areas that play essential roles in maintaining marine ecosystem balance and protecting shorelines from erosion. Although covering only 0.7% of global forest area (13.4 million ha), mangroves store substantial carbon and provide vital ecosystem services. Indonesia holds the world’s largest mangrove area, approximately 3.1 million ha, or 22.6% of the global mangroves, encompassing over 202 species, including 43 true mangroves and 159 associated species. Mangrove degradation due to conversion to other land uses is a major threat to the Indonesian mangrove ecosystem. Mangrove planting/restoration is a common way to restore degraded mangroves. However, the question remains whether mangrove restoration has been able to restore the structure and composition of mangrove forests to the level of natural forests. Studies of mangrove structure and composition are often considered outdated and may be losing popularity in this digital age. This study systematically reviewed literature on mangrove structure and species composition across 25 Indonesian provinces using the Population, Intervention, Comparison, and Outcome (PICO) framework. We included a total of 105 research articles published between 2009 and 2023, providing up-to-date insights into mangrove ecosystems and restoration programs. To evaluate the effectiveness of restoration and ecological indicators across 105 peer-reviewed studies, we conducted a quantitative systematic synthesis. The results show that government-led programs, especially those planting Rhizophora apiculata seedlings, have effectively increased the number and types of mangrove species in important areas. Provinces such as East Kalimantan, West Kalimantan, North Kalimantan, West Nusa Tenggara, Riau, and North Sumatra were identified as high-priority areas for restoration. Findings highlight the importance of understanding forest structure, composition, and distribution to guide targeted restoration efforts and improve ecological outcomes. Future research should evaluate long-term survival and growth of planted seedlings, assess socio-economic benefits for local communities, and develop species-specific restoration protocols to enhance the resilience and sustainability of Indonesia’s mangrove ecosystems.