iarjalsIARJALSIARJALS2708-5104https://doi.org/10.47310/iarjals.2023.v04i02.006Comparative assessment of stomata conductance (Gs) and transpiration (Tr) between young and old leaves in savanna treesWycliffOronyiJohnMainaNyongesahDenisOchuodhoOtienoAlthough stomata conductance (Gs) and transpiration (Tr) are important for gas exchange (CO2 and H2O), none of the available studies have considered variation in Gs and Tr between old and young leaves in savanna trees such as (Combretummolle, Piliostigmathonningii and Balanites aegyptiaca). The study aimed at addressing variability in Tr and Gs of three species and their response to changes in canopy microenvironment. Measurements were conducted in Ruma National park. Two treatments and three replications were used in the experiment arranged in a completely randomized design. Results revealed that all the three species recorded highest Tr and Gs in young leaves compared to older leaves. P. thonningii exhibited the highest values followed by C. molle and B. aegyptiaca with the least. Highest Gs of 1.092±0.73 µg cm-2 s-1 was recorded in young leaves of P. thonningii. Similarly, highest mean Tr of 15.73±0.92 µg cm-2 s-1 was recorded in young leaves of P. thonningii followed by C. molle (13.02±1.6 µg cm-2 s-1). There was no significant relationship (p<0.05) between Tr of old leaves of all the species with leaf temperature. B. aegyptiaca, and C. molle exhibited a positive relationship between Tr and VPD in old and young leaves with highest coefficient of determination of R2 = 0.9 obtained in B. aegyptiaca and P. thonningii. Our findings show that estimations of the rate of Tr and Gs is species specific and relies on the microenvironment that the selected leaf is exposed to as well as the age of the leaves. When modeling Tr and Gs from humid tropical savanna trees, generalization of leaf physiological traits is likely to present contradicting results that may underestimate or overestimate their gas exchange attributes.