Mangrove Carbon Pool Patterns in Maharashtra, India

This study attempts to investigate whether the mangroves of Maharashtra, India, are acting as a source or sink of carbon. Additionally, efforts were made to develop the empirical model using ground-based tree biomass and satellite-based indices to estimate above-ground biomass (AGB) for the state of Maharashtra for the year 2018–19. Total of 44 geotagged, well-distributed sample plots (0.1 ha each) were laid down to measure the tree girth and height (of all the trees) of different mangrove species. The available biomass equations were used to estimate the AGB at the plot level. Normalized Difference Vegetation Index (NDVI) and plot-wise AGB correlation were tested for minimum, maximum, sum and amplitude of stacked monthly NDVI. The strongest correlation of AGB was observed with maximum NDVI and was therefore used in regression analysis to estimate the AGB and carbon present in mangroves. Carbon values ranged from 2.78 to 249.64 t C ha−1. Carbon sequestration was estimated using statistical method by estimating the difference in total carbon content within the mangroves between the years 2005–06 and 2018–19. Total carbon content was determined by multiplying per hectare AGB with the mangrove area for the respective years. In 2005–06, the carbon pool in the state amounted to 1.08 × 106 tonnes, which increased to 1.32 × 106 tonnes by 2018–19. The mangroves in Maharashtra sequestered a total of 0.24 × 106 tonnes of carbon from 2005–06 to 2018–19, confirming their role as a carbon sink.