Coastal Forests at the Crossroads: Ecological Baseline Assessment of Mangroves in Belen, Calabanga for Sustainable Management and Community Governance

Mangrove forests function as coastal forest ecosystems that provide critical biodiversity, ecological services, and climate protection. Despite their importance, many mangrove stands remain understudied, limiting evidence-based conservation and community governance. This study establishes a comprehensive ecological baseline for the mangrove forest of Barangay Belen, Calabanga, Philippines—an area experiencing both ecological value and emerging environmental stress. A rapid ecological assessment (REA) was conducted, involving short-term standardized field surveys integrating species identification, vegetation structure analysis, phenological observations, physico-chemical measurements of soil and water, and surveys of pests and disease symptoms. Transect–quadrat sampling, in situ environmental testing, and visual health assessments were applied to characterize forest composition and condition. Sixteen true mangrove species and two associates were recorded, including threatened taxa such as Avicennia marina var. rumphiana, Aegiceras floridum, and Brownlowia tersa. Vegetation metrics showed the structural dominance of A. marina var. rumphiana, while phenology indicated active flowering and propagule production among most species, reflecting strong natural regeneration. Environmental diagnostics revealed potential stressors, including low dissolved oxygen levels, high nitrate concentrations, elevated soil moisture, and nutrient imbalances. Pest and disease assessments identified woodborers, folivores, and fungal infections, with higher incidence in dominant species, suggesting interactions between hydrological stress and biotic disturbance. The combined ecological, environmental, and forest health assessments reveal a mangrove ecosystem with high biodiversity potential, yet increasing vulnerability due to environmental and biotic pressures. These findings provide a scientific foundation for sustainable management strategies, including hydrological improvement, diversified restoration, nutrient-source control, and community-based monitoring. As coastal forests face intensifying climate risks, this baseline supports the development of informed governance and resilience planning for the mangroves of Belen.