The carbon stock, biomass, and CO2 emissions in woody species play crucial roles in understanding and managing ecosystems. Understanding these aspects is crucial for sustainable forest management, conservation, and mitigating the impact of woody species on global carbon dynamics and climate change. This study examined the nexus between carbon stock, biomass, and CO2 emission of woody plant composition in disturbed and undisturbed areas in Southwestern Nigeria. The study involved the random establishment of plots in the disturbed and undisturbed areas and, in each plot, the woody plants were enumerated and identified to the species level. The results showed that total biomass (102.645 Mg ha-1), total carbon stock (51.323 Mg C ha-1), and total CO2 emission (188.354 Mg C ha-1) values of tree species in undisturbed plots were higher than the values of total biomass (70.768 Mg ha-1), total carbon stock (35.384 Mg C ha-1), and total CO2 emission (129.859 Mg C ha-1) recorded in disturbed plots. The results also revealed that total biomass (0.123 Mg ha-1), total carbon stock (0.061 Mg C ha-1), and total CO2 emission (0.225 Mg C ha-1 ) values of shrub species recorded in disturbed plots were higher than values of total biomass (0.067 Mg ha-1), total carbon stock (0.034 Mg C ha-1) and total CO2 content (0.124 Mg C ha-1) recorded in undisturbed plots, respectively. The findings showed that in undisturbed and disturbed plots of shrubs, biomass, carbon and CO2 emissions have a strong positive correlation of 1.000**. While biomass, carbon, and CO2 emission have a very strong positive correlation (0.999**) in undisturbed plots of trees, the biomass, carbon, and CO2 emission have moderate to strong positive correlations (0.458** to 0.974**) in disturbed plots of the tree. The study concluded that while biomass, carbon stock, and CO2 emission values of tree species were higher in undisturbed plots than in disturbed plots, the biomass, carbon stock, and CO2 emission values of shrub species were lower in undisturbed plots than in disturbed plots. It also concluded that the main purpose of establishing reserve forests is not totally achieved as human activities occurring in reserve forests still contribute to the increment of climate change.
