Impact of soil salinity on structural attributes and above ground biomass carbon in a mangrove community of a Colombian Caribbean Coast

Mangrove forests are known for their exceptional carbon storage capacity, but the influence of environmental factors on this service remains understudied. This study examines how environmental conditions shape tree community composition and carbon storage in Mallorquin Swamp, an urban mangrove ecosystem in Barranquilla, Colombia. We assessed tree composition, vegetation structure, soil pH, and salinity across 18 circular plots in areas of Low, Medium, and High salinity. Above ground biomass (AGB) and carbon stock were estimated using allometric equations and wood density databases. Our findings revealed significant salinity differences among sampling areas, especially during the dry season, while soil pH showed minimal variation. Avicennia germinans was dominant in Low salinity areas, Laguncularia racemosa in Medium salinity areas, and Rhizophora mangle in High salinity areas. Trees in Low salinity zones were notably taller and larger, contributing to significantly higher carbon stock (4098.6 Mg C) compared to Medium (104.6 Mg C) and High (1761 Mg C) salinity areas. These results underscore the importance of local environmental factors, particularly salinity, in shaping mangrove structure and carbon dynamics. Identifying such patterns is vital for guiding conservation efforts and carbon policies, particularly in urban and climate-sensitive areas, where focused management can strengthen mangrove resilience and carbon storage.