Effect of Restoration Actions on Organic Carbon Pools in the Lagoon-Delta Cienaga Grande de Santa Marta, Colombian Caribbean

Mangroves provide multiple ecosystem services and are essential for mitigating global warming owing to their capacity to store large carbon (C) stocks. Due to widespread mangrove degradation, actions have been implemented to restore them worldwide. An important representative case in Colombia is the Cienaga Grande de Santa Marta's restoration plan. This management intervention focused on restoring the natural hydrological functioning after massive mangrove mortality (similar to 25,000 ha) due to soil hyper-salinization after river water input from the Magdalena River was eliminated. A partial recovery occurred during subsequent years, and hydrological management is still being implemented today. To understand how the degradation and subsequent management have affected mangrove C stocks, we compared C stocks in stands with different intervention levels reflected in their current forest structure. We found that the total C stock (398-1160 Mg C ha(-1)) was within the range measured in other neotropical mangroves without vegetation deterioration. The aboveground C was significantly higher in the stands where hydraulic connectivity was restored. By contrast, the belowground C was higher in the stands with low hydraulic connectivity due to channel clogging and a lack of sufficient maintenance. Our results show that hydrological management measures influenced above- and belowground C stocks, even at a 2 m depth. In addition, a strong indirect relationship useful for estimating carbon content from organic matter content was found.

Automated summary

Mangroves provide crucial ecosystem services and play a key role in mitigating global warming due to their ability to store large carbon stocks. Restoration actions have been implemented worldwide due to widespread mangrove degradation. An important case study in Colombia focused on the restoration plan for Cienaga Grande de Santa Marta, which aimed to restore natural hydrological functioning after massive mangrove mortality caused by soil hyper-salinization.