NIGERIAN JOURNAL OF FORESTRY

Carbon dioxide is the primary greenhouse gas emitted by human activities, caused global warming and subsequently climate change. This study therefore assessed aboveground biomass and carbon stock of eight (8) year old stands of Khaya senegalensis, Tectona grandis and Gmelina arborea in Nasarawa State University Forestry Plantations, Lafia.

The study also developed height-diameter models, for the management of these three tree species. Data were collected from ten (30) temporary sample plots of 0.01 ha size randomly located in each of the stands of the three tree species. The statistical selection indices for the height diameter models revealed that model two (2) with AIC (26.83489), BIC (31.03848) and RSE (0.3544) of Khaya Senegalensis, model one (1) with AIC (71.06), BIC (75.27) and RSE (0.74) of Tectona grandis and model five (5) with AIC (-212.0001), BIC (-206.3953) and RSE (0.00652) of Gmelina arborea were the best and grand models for predicting tree heights of the three forest plantations in the study area. The results also showed that Gmelina arborea has the highest biomass of 2501.8054145kg/ha, Carbon Stored of 1250.9027072kg/ha, CO2 of 4590.8129357kg/ha when compared to Khaya senegalensis biomass of 1436.0432204kg/ha, Carbon Stored of 718.0216102kg/ha, CO2 of 2635.1393092kg/ha and Tectona grandis biomass of 1514.7782607kg/ha, Carbon Stored of 757.3891304kg/ha, CO2 of 2779.6181083kg/ha.

Therefore, Gmelina arborea has the highest potential to capture and store Carbon (C) in form of wood, provide substantial oxygen to sustain living organisms, balance the earth ecosystem to avert severe global warming and climate change among the three tree species in the study area.