8. Protected Areas for Climate Change Mitigation and Livelihood Option: A Case Study of the Bangladesh Sundarbans Mangrove Forest

Carbon sequestration is an important REDD+ strategy to global climate change mitigation and adaptation, biodiversity protection, and livelihood generation. This study investigated the floristic composition, ecosystem level carbon sequestration, and relation between forest composition and carbon pools in three protected areas (PAs) of the Bangladesh Sundarbans Mangrove Forest. Systematic grid sampling method was employed to collect data from a total of 29 cluster plots composed of five nested circular (10 m radius) subplots of equal size (1570.50 m²) each during two forest inventories (in 1997 and 2010). Mean diversity, evenness, and richness of all recorded species were respectively 1.21, 0.37, and 0.59. No significant difference was observed between species diversity, evenness, and richness across three PAs. The mean ecosystem level carbon stock was measured 218.72 Mg ha⁻¹. The ecosystem level carbon stocks were found significantly different across the three PAs. The Sundarbans East Wildlife Sanctuary contained the highest amount of carbon (299.49 Mg ha⁻¹) followed by the Sundarbans South Wildlife Sanctuary and the Sundarbans West Wildlife Sanctuary. There was no significant relationship with carbon (above- and belowground) content with species diversity, evenness, and richness. Shrub-herb carbon stocks showed significant negative correlation with species diversity and evenness. We found significant variation in ecosystem level carbon sequestration across the three wildlife sanctuaries. The mean yearly ecosystem level carbon sequestration rate was 3.93 Mg ha⁻¹ equivalent to 14.44 Mg CO₂ ha⁻¹. Thus, the three PAs with its total land cover of 90,747 ha (22 % of the entire mangrove Sundarbans) have been sequestering 1.31 million ton CO₂ per year which can earn 19.65 million USD yearly (@15 USD/t CO₂). Thus, the Sundarbans Mangrove Forest has enormous potential to address global climate change mitigation, biodiversity conservation, and perhaps more importantly livelihoods to millions of people through participating in Payment for Environmental Services (PES) of the REDD+ financial mechanism.