Estimation of Ecosystem Carbon Stock and Tree Species Diversity at National Botanical Garden, Dhaka, Bangladesh

The study was conducted from January to April 2018 to estimate ecosystem carbon stock and tree species diversity at National Botanical Garden, Bangladesh. Transects line method square plots with a size of 20 m × 20 m were used. So altogether there were total eighty-three sample plots in National Botanical Garden. Above ground carbon (AGC) and below ground carbon (BGC) biomass stock was 192.67 and 31.34, respectively and soil organic carbon mean value of 27.52 Mg ha-1, 21.45 Mg ha-1 and 16.23 Mg ha-1, respectively for 0-10 cm depth, 10-20 cm and 20-30 cm depth. The average number of tree species per hectare was 128 with a mean value of each plot 3.00 to 9.00 species. The average number of trees in National Botanical Garden (233 tree ha-1), basal area (21.45 m2 ha-1) and mean DBH (39.86 cm). Tree diversity range from 0.25 to 1.86 and the mean value of (0.93 ± 0.14) in National Botanical Garden. A relationship such as biomass carbon with the basal area, mean DBH, stem density and tree diversity were estimated. Among these, the relationship between basal area and biomass carbon showed positive significant correlation. Therefore, the results of the study confirmed that the selected botanical garden can serve as a valuable ecological tool in terms of carbon sequestration, diverse tree species and storage of soil organic carbon.