Armazenamento e sequestro de carbono em manguezal: estoques totais e variação temporal em uma área em recuperação na APA do Rio Pacoti/CE

Abstract

Mangroves are excellent ecosystems as carbon sinks, capable of storing carbon at levels higher than those of many terrestrial ecosystems. In the context of the climate crisis, these environments can act as natural mitigation solutions, provided they are preserved and restored. The objective of this study was to estimate the carbon stock in the above-ground and below- ground living biomass (AGB and BGB) compartments and in the soil of the mangrove forest in the Pacoti River Environmental Protection Area (APA) in Ceará, Brazil. The study sought to compare an area of young mangrove forest undergoing ecological recovery with unaffected surrounding areas, as well as to analyze the temporal variation in carbon storage from 2019 to 2025 in the recovering area. As a methodology, three sampling strata were defined for comparison: Stratum M1, which is an undisturbed mangrove forest located farther from the river; Stratum RM, which represents a young, developing forest; and Stratum M2, which is also an undisturbed forest bordering the river. In each area, five 5 x 5-meter plots were demarcated, and in each plot, data on diameter at breast height (DBH), identification of mangrove plants at the species level, and soil samples were collected to a depth of 3 meters. Consequently, biomass data were obtained using allometric equations and converted to carbon content, while soil samples were analyzed using an elemental analyzer. The results indicated average carbon stocks of 74.09 Mg C/ha for ABG, 50.75 Mg C/ha for BGB, and 344.04 Mg C/ha for the soil. In summary, the area undergoing restoration had the lowest carbon stocks among the areas analyzed; however, the temporal assessment showed an average annual increase of 2.59 Mg C ha−1 year−1 for AGB and 1.82 Mg C ha−1 year−1 for BGB, indicating the success of the mangrove restoration project in semi-arid conditions. Thus, the results reinforce the importance of mangrove preservation and restoration as a strategy aligned with SDG 13 (Climate Action), among others.