Table I. Results of computer model simulations of the PLC of K_x, after reducing major and minor vein conductivities to simulate cavitation, in realistic leaves varying in major or minor vein density.

Contrasting impacts were found for the impacts of higher major and minor vein densities on the PLC of K_x due to vein cavitation, and contrasting impacts were found when cavitating major or minor veins. These effects can be understood in terms of the relative leverage of major or minor veins on the overall vein system. When the major vein density is increased, its greater redundancy gives the minor vein system a greater leverage; thus, the leaf is less sensitive to cavitation in the major veins and more sensitive to cavitation in the minor veins. By contrast, when the minor vein density is increased, its greater redundancy gives the major vein system a greater leverage; thus, the leaf is more sensitive to cavitation in the major veins and less sensitive to cavitation in the minor veins.

Leaf Simulation	Cavitation in Major Veins	Cavitation in Minor Veins
Higher major vein density	Lower Kx decline	Greater Kx decline
Higher minor vein density	Greater Kx decline	Lower Kx decline
Higher major:minor vein density	Lower Kx decline	Greater Kx decline