Estimating Above-Ground Biomass of the Mangrove Communities in the Muthurajawela Wetland, Sri Lanka

Abstract

Muthurajawela wetland is the largest saline coastal peat bog in Sri Lanka, contains a high diversity of both flora and fauna. In Muthurajawela wetland, mangrove forests are scattered along the Gampaha District of Western Sri Lanka, and are dominated by the Rhizophora mucronata, Bruguiera cylindrica, Annona glabra. This paper presents the results of the above-ground biomass (AGB), carbon stocks and CO2 content of mangrove communities in Muthurajawela wetland, in order to gather better information to support the improved management of mangrove forests in this region. 36 plots were set up and 60 samples tree (Rhizophora mucronata, Bruguiera cylindrica, Annona glabra and Other woody species) was collected. Then, analyzing, processing data, setting the correlation equation between DBH and biomass. The results showed that average green biomass of Bruguiera gymnorrhiza was 31.29 kg/tree (equivalent average dry biomass of 17.21 kg/tree). Annona glabra 20.60 kg/tree (equivalent to 10.90kg/tree dry biomass). Rhizophora mucronata was 42.91kg/tree (average dry biomass was 24.03 kg/tree, not including roots). Other woody species (Sonneratia caseolaris, Hibiscus tiliaceus, Excoecaria agallocha, Cerbera manghas, Syzygium caryophyllatum, Dolichandron spathacea, Pandanus tectorius.) averaged 29.50 kg/tree (equivalent to 15.90kg/tree dry biomass).The total biomass of the mangrove population in Muthurajawela wetland was 447,357.48 tons (245,174.07 tons dry biomass). The total amount of carbon was 115,231.81 tonsC (22.05 tonsC/ha), equivalent 422,516.64 tons CO2 (80.86 tons CO2/ha).