In order to contribute to understand the factors that control the provisioning of the ecosystem service of carbon storage by mangroves, data on carbon stock and sequestration in the aboveground biomass (AGB) from 73 articles were averaged and tested for the dependence on latitude, climatic parameters, physiographic types and age. Global means of carbon stock (78.0 ± 64.5 tC.ha^-1) and sequestration (2.9 ± 2.2 tC.ha^-1.yr^-1) showed that mangroves are among the forest ecosystems with greater capacity of carbon storage in AGB per area. On the global scale, carbon stock increases toward the equator (R²=0.22) and is dependent on 13 climatic parameters, which can be integrated in the following predictive equation: Carbon Stock in AGB = -16.342 + (8.341 x Isothermality) + (0.021 x Annual Precipitation) [R²=0.34; p < 0.05]. It was shown that almost 70% of carbon stock variability is explained by age. Carbon stock and sequestration also vary according to physiographic types, indicating the importance of hydroperiod and edaphic parameters to the local variability of carbon stock. By demonstrating the contribution of local and regional-global factors to carbon stock, this study provides information to the forecast of the effects of future climate changes and local anthropogenic forcings on this ecosystem service.

Although mangroves are recognized by high capacity of carbon storage and sequestration, few studies have been dedicated to determine the monetary value of this ecosystem service. Accordingly, the aim of this study is to assign monetary values to this service in a protected area (Southeastern Brazil). This economic valuation was performed considering preexisting estimates of carbon storage and sequestration in the aboveground biomass of these forests and average transaction values of carbon credits. The mean values of the service of carbon sequestration varied according to the physiographic type from 19.00 ± 10.00 US$ ha⁻¹ yr⁻¹ (basin forests, high intertidal) to 82.28 ± 32.10 US$ ha⁻¹ yr⁻¹ (fringe forests, low intertidal). Considering the area occupied by each physiographic type, the service of carbon sequestration may be worth up to 455,827 US$ yr⁻¹. In regard to carbon storage, 3,477,041 US$ are stored in these forests, and values between 104,311 and 208,622 US$ ha⁻¹ yr⁻¹ can be considered as the annual maintenance cost of this service. The income generated by future projects for the maintenance of carbon-related functions may represent a major advance for the conservation of this ecosystem.