Evaluation of carbon sequestration in above-ground biomass of three avenue tree species planted in Uyo Metropolis, Akwa Ibom State, Nigeria

Abstract

There is dearth of quantitative scientific information on carbon sequestration potentials of most commonly planted tree species in Nigerian urban areas, which are needed in the synergy for climate change mitigation and adaptation. Accordingly, three avenue tree species, viz: Terminalia mantaly, Delonix regia and Hura crepitans, of about thirteen years old planted along some avenues in Uyo metropolis, Akwa Ibom State, Nigeria were randomly sampled and assessed for carbon stocks in above-ground biomass. All the randomly sampled trees were measured for stem diameters and heights. Algorithm functions were employed for the determination of above-ground biomass and sequestered carbon. The data obtained were subjected to descriptive statistical analysis and one-way analysis of variance. Separation of means of significant differences between variables was done using least significant difference test. The results revealed that D. regia had the highest mean tree above-ground biomass of 1.58 ton and mean tree carbon stock of 0.79 ton, while T. mantaly had the least of 0.88 ton and 0.44 ton respectively for mean tree above-ground biomass and mean tree carbon stock. There were significant differences between the tree species above ground biomass and carbon stocks (p<0.05). The separation of means indicated that significant differences specifically occurred between D. regia and T. mantaly; H. crepitans and T. mantaly, while there was no significant difference between D. regia and H. crepitan. It is therefore concluded that D. regia should be the most preferred species for planting in the study area to mitigate global warming, because it had the highest mean tree above-ground biomass and carbon stock.