This work combines the mechanical and hydrological effects of vegetation with a slope stability
framework. The analysis provides further understanding of the effects of vegetation on slope stability
analysis. From the results obtained, trees contribute to the stability of sloping ground both hydrologically as
a result of increase in matric suction of the soil resulting in a increase in the shear strength while
mechanically is due to root reinforcement, the shear strength of the rooted soil mass is enhanced due to the
presence of a root matrix. It is found that the most significant benefit is likely to be achieved only when the
tree is located at the toe of the slope. The results indicate that the Factor of Safety against failure can
increase by more than 8% when including the influence of a mature tree located at toe of a slope. The
results also indicate that the mechanical contribution to strength offered by vegetation is much greater than
the influence of hydrological effects
