High blue carbon stock in mangrove forests of Eastern India

Abstract

Present study focuses on the carbon sequestration potential of five dominant mangrove species (Avicenia marina, Avicenia officinalis, Excoecaria agallocha, Rhizophora mucronata and Xylocarpous granatum) in Bhitarkanika and Mahanadi mangrove ecosystem. Water and soil parameters were sampled and analyzed for 10 selected stations along with aboveground biomass (AGB) and aboveground C (AGC) values. AGB value in the study area ranged from 15.00 ± 2.12 to 70.09 ± 6.68 tha−1 for A. marina, 26.13 ± 3.19 tha−1 to 616.94 ± 50.15 tha−1 for A. officinalis, 3.56 ± 0.96 tha−1 to 98.66 ± 5.24 tha−1 for E. agallocha, 7.06 ± 2.21 tha−1 to 224.41 ± 21.20 tha−1 for R. mucronata, and 0.64 ± 0.21 tha−1 to 6.25 ± 1.52 tha−1 for X. granatum, respectively. AGC value ranged from 7.63 ± 1.08 to 35.65 ± 2.63 tha−1 for A. marina, 1.73 ± 0.01 tha−1 to 280.83 ± 21.29 tha−1 for A. officinalis, 1.64 ± 0.41 tha−1 to 44.95 ± 2.53 tha−1 for E. agallocha, 3.44 ± 1.45 tha−1 to 114.05 ± 10.29 tha−1 for R. mucronata and 0.31 ± 0.10 tha−1 to 3.25 ± 0.31 tha−1 for X. granatum, respectively. The average SOC values in tha−1 varied from 3.52 ± 0.12 to 7.71 ± 0.45. The total carbon (AGC + SOC) calculated for the study area varied from 55.20 ± 7.90 to 330.41 ± 111.97 tha−1 with a mean total carbon of 124.11 ± 30.14 which is equivalent to 455.47 ± 110.56 tons of CO2. Considering the total area of Bhitarkanika and Mahanadi mangrove ecosystem (672 + 141,589) to be 142,261 km2, the mean CO2e be 455.47 ± 110.56 tones, it is approx. 64,795,617.67 ≅ 64.80 TgC that were absorbed from the atmosphere, thus reducing the amount of carbon dioxide from the atmosphere.