Vegetation structure, biomass and carbon retention capacity of mangroves at Northeast coast of Sri Lanka

Mangroves represent one among the most carbon retaining ecosystems in the world, due to their high productivity and huge carbon sinking capacity within biomass and substratum. Majority of Sri Lankan mangroves are located on the north-eastern coast. Since they were highly isolated during the last three decades, there are limited research publications related to those. Present study was conducted at six major mangrove ecosystems in the northeast coast of Sri Lanka with the objectives of reporting the present vegetation structure and to estimate their capacity of the carbon pool with plant biomass. Highest mangrove diversity was recorded at Yanoya followed by Thondamannaru and Uppar lagoons. A critically endangered mangrove species, Ceriops decandra, was recorded at Yanoya mangrove ecosystem, this may be the first-time scientific record of the species in the recent history. Relatively higher biomass values (159 - 460 Mg ha-1), recorded at Yanoya estuary. The average value for above ground biomass of the northeast coast of Sri Lanka was 226.34 Mg ha-1. Statistically significant linear relationships occurred between the biomass and the mangrove vegetation structure, as well as between the soil salinity and the carbon retention capacity of mangrove. Results of the present study assist to add new knowledge and rationalize the conservation and proper management of mangrove ecosystems on the northeast coast of Sri Lanka.