CO₂ Removal from Above-ground Biomass (AGB)

The annual CO₂ removal of the Above-ground Biomass (AGB) is calculated with the following equation:

The Above-Ground Biomass (AGB) Sequestration Rate (tC/ha/year) represents the annual amount of carbon stored in the above-ground biomass of mangrove trees per hectare. This metric is expressed in metric tons of carbon (tC) sequestered per hectare annually and serves as a key indicator of how effectively mangrove vegetation absorbs atmospheric carbon dioxide (CO₂) and incorporates it into its biomass.

The IPCC 2013 Wetlands Supplement (Table 4.4) provides default values for AGB sequestration rates categorized by climate domain and region. Additionally, IPCC Chapter 4, Volume 4 (Table 4.10) includes further details based on ecological zones and specific mangrove tree species. These sources provide Tier 1 default values, which are widely accepted for general use when more detailed, localized data is unavailable. To ensure accuracy in the Above-ground biomass (AGB) sequestration rates used:

1. Tier 1 Approach: Default rates provided by the IPCC are used in cases where site-specific data is not available.
2. Refined Approaches (Tier 2 or 3): When available, project-specific data or values derived from peer-reviewed studies are prioritized. For example, mangrove restoration projects dominated by species such as Rhizophora mucronata can apply updated sequestration rates that reflect the species' specific growth conditions and regional ecological characteristics. These may be obtained through recent scientific literature or direct field measurements.

This approach balances the use of standardized guidelines with the integration of site-specific data to enhance the credibility and accuracy of carbon accounting in mangrove afforestation and reforestation projects.