First assessment of the blue carbon storage of Rhizophora and Bruguiera mangrove stands on the island of Mauritius (western Indian Ocean)

Abstract

Blue carbon has gained recognition as a strategy to mitigate climate change. Mangroves allow significant amounts of carbon to be sequestered and stored and are considered an important component in the offset of greenhouse gas emissions. Despite this, little is known about the ecosystem-level carbon storage of the mangrove stands of Mauritius, western Indian Ocean. We conducted an inventory of mangrove stands to characterise forest stand structure and estimate carbon stocks in terms of aboveground biomass and soil carbon at two sites, Ferney and Pointe d’Esny. Different allometric equations relative to species (for areas dominated by Rhizophora mucronata or Bruguiera gymnorrhiza) were used for aboveground biomass, and the loss-on-ignition method was used for estimating soil carbon. The results showed that aboveground biomass ranged from 54.57 Mg ha−1 to 328.71 Mg ha−1, and soil carbon from 99.11 ± 18.35 Mg ha−1 to 133.45 ± 30.35 Mg ha−1. The total ecosystem carbon stock ranged from 402.35 ± 19.29 Mg ha−1 to 427.81 ± 18.35 Mg ha−1 at Ferney, and from 188.03 ± 30.35 Mg ha−1 to 189.72 ± 19.27 Mg ha−1 at Pointe d’Esny. Our results underscore the importance of mangrove forest stands and highlight the need for in-depth and broader spatial-scope research on blue carbon ecosystems in Mauritius.

Keywords: aboveground biomass; blue carbon strategy; carbon stock analysis; climate change mitigation; soil carbon; stand structure