COMPARATIVE STUDY ON CARBON SEQUESTRATION POTENTIALS OF INDIGENOUS AND EXOTIC TREE SPECIES IN AKURE FOREST RESERVE OWENA-AKURE, ONDO STATE, NIGERIA

Forests play a vital role in mitigating climate change through carbon sequestration, yet limited comparative information exists on the carbon storage potential of indigenous and exotic tree species under the same ecological conditions in Nigeria. This study assessed and compared the carbon sequestration potentials of selected indigenous (Mansonia altissima and Celtis zenkeri) and exotic (Tectona grandis and Gmelina arborea) tree species in Akure Forest Reserve (Strict Nature Reserve), managed by the Forestry Research Institute of Nigeria (FRIN), Ibadan. The specific objectives were to obtain density, estimate the volume, above-ground biomass, and carbon stock of the selected tree species. Data were collected using population sampling and locate the designated tree species. The tree growth variables such as diameter at breast height (DBH), diameter at the base, middle and top as well as total height were measured. Biomass was estimated using tree volume and density, and converted to carbon stock using 0.5 conversion factor. Afterwards, analysis of variance was employed to test for significant differences among the carbon stocks of these tree species. The results revealed that indigenous tree species (Mansonia altissima), had the highest carbon accumulation compared to other tree species. Significant differences were observed in carbon sequestration potentials among the tree species, confirming the significant disparity in their carbon storage capacity. Though, the study concluded that both indigenous and exotic tree species contribute meaningfully to carbon sequestration potentials of the Strict Nature Reserve. The study recommends integrating both indigenous and exotic species into plantation and conservation programs, while strengthening country climate change mitigation strategies