Carbon Stocks of Tropical Coastal Wetlands within the Karstic Landscape of the Mexican Caribbean

This is research study was sponsored by USAID and carried out by the Center for Research and Advanced Studies, of Mexico’s National Polytechnic Institute. It quantified the carbon stocks of coastal wetlands of the Sian Ka’an Biosphere Reserve in the Yucatan Peninsula.

Coastal wetlands can have exceptionally large carbon stocks and their protection and restoration would constitute an effective climate mitigation strategy. Including coastal ecosystems in such strategies requires quantification of carbon stocks in order to calculate emissions or sequestration through time.

At nine sites within the reserve, researchers quantified the carbon stocks by measuring above and belowground biomass, downed wood, and soil carbon. They also measured nitrogen and phosphorus from the soil and interstitial salinity.

They found that tall mangroves contained the highest carbon (9876338 Mg ha21), followed by medium mangroves (623641 Mg ha21), dwarf mangroves (381652 Mg ha21) and marshes (177673 Mg ha21). At all sites, soil carbon comprised the majority of the ecosystem carbon stocks (78–99%).  

The highest carbon stocks were measured in soils that were relatively low in salinity, high in phosphorus and low in the ratio of nitrogen to phosphorus, suggesting that phosphorus limits carbon sequestration and accumulation potential.

Sian Ka’an’s coastal wetlands, covering about 170,000 hectares, may store 43.2 to 58.0 million Mg of carbon.