Development of an Empirical Correlation for Root Water Uptake and Total Leaf Area of “Alstonia Macrophylla” Using Potometer

Using vegetation for ground improvement is a sustainable, environmentally friendly, and cost-effective approach. The increase in shear strength and stiffness of soil is mainly due to the suction induced by root water uptake and the mechanical reinforcing effect provided by the tree roots. The root water uptake of the tree relies on the physiology of the tree and environmental parameters. The total leaf area, number of stomata present in a leaf, root system, spatial distribution of roots, etc. influence the root water uptake as the physiological parameters. In this study, an empirical correlation was developed between the root water uptake (S_p) and total leaf area (TLA) of Alstonia macrophylla (Attonia). A Potometer, which can be used to measure the transpiration of a small tree, was kept in a controlled environmental condition to eliminate the influence of extraneous variables. Previous studies have revealed that more than 99% of root water uptake is lost through leaf transpiration. Consequently, it was assumed that the amount of water lost through transpiration is equivalent to the amount of water taken up by the roots at any given time. This assumption leads to approximating the root water uptake rate by measuring the transpiration rate using a Potometer, which uses the traveled distance of an air bubble in a small glass tube.