ESTIMATION OF ABOVEGROUND BIOMASS AND CARBON STOCK ASSESSMENT IN THE BUILT-UP AREA OF ABDULLAHI FODIYO UNIVERSITY OF SCIENCE AND TECHNOLOGY ALIERO, KEBBI STATE

This study assessed the aboveground biomass (AGB), belowground biomass (BGB), and carbon
sequestration capability of tree species in the developed area of Abdullahi Fodio University of
Science and Technology, Aliero (KSUSTA). A total of 106 stems from seven species were
catalogued over 15 plots utilizing conventional dendrometric metrics, including diameter at
breast height (DBH) and tree height. Biomass was calculated using standard allometric
formulae, and carbon stock was determined as 50% of total biomass. The results indicated
substantial differences in tree dimensions and carbon sequestration among the plots. Plots with
greater average DBH, namely Plot 10 and Plot 2, had the greatest carbon stores of 5.01 Mg C
and 4.25 Mg C, respectively, while plots with smaller stems held negligible carbon, frequently
below 0.20 Mg C. At the species level, Azadirachta indica was the predominant contributor,
with 9.84 Mg C (36.07 Mg CO₂e), followed by Eucalyptus camaldulensis with 5.60 Mg C (20.55
Mg CO₂e). Other species, such as Khaya senegalensis, Terminalia mantally, and Albizia spp.,
contributed somewhat, although Gmelina arborea and Olea europaea played minimal roles due
to their low abundance. The findings reveal that carbon storage is unevenly distributed among a
limited number of dominant species and larger individuals, consistent with worldwide data on
tree size-carbon relationships. The study concludes that institutional plantations possess
considerable potential for carbon sequestration when managed with an emphasis on high
performing species. It recommends the conservation of mature trees, diversification of species,
and the incorporation of carbon management strategies into campus landscaping as components
of climate change mitigation efforts.