HARNESSING URBAN TREES FOR CLIMATE ACTION: LESSONS FROM CARBON SEQUESTRATION AT THE UNIVERSITY OF KARACHI

This study indicates significant species diversity with variability in growth parameters and showed carbon stock potential of dominant trees species across the University of Karachi campus. The mean diameter at breast height (DBH) (93.48 ± 13.53 cm) of Tamarindus indica L. is over twice as Eucalyptus camaldulensis Dehnh and the mean BA (Basal Area) (6996.80 ± 2138.66 cm2 ) incredibly larger than all others, suggesting trees with much greater DBHs and total volume of wood. The mean DBH of E. camaldulensis (35.92 ± 17.10 cm) and Ficus religiosa L. (36.795 ± 8.83 cm) have the next higher DBH, thus having relatively high mean BAs (1241.71 and 1118.97 cm2 correspondingly). E. camaldulensis, Melia azedarach L., Guaiacum officinale L. and T. indica consistently register relatively larger Total Biomass (TB), carbon stock and CO₂ equivalent values. While Conocarpus erectus L., F. religiosa and Mangifera indica L. have much lower values for these measures reflecting their less contribution to the overall biomass and carbon stock. It was observed the total amount of 1657.355 tons of CO2 is heavily dominated by sampled species. Species diversity analysis revealed low species richness and evenness, with a Shannon index of 1.602, Shannon equitability of 0.72 and a Simpson index of 0.7692, suggesting dominance by a few species.