Radial patterns of sap flux densities at the western (left) and the eastern (right) sides of the maple stem demonstrating water portioning from the corresponding root sectors (black thin lines) to the main (black thick lines) and the lateral (grey thick lines) branches. R_xyl means stem radius in a measured place without bark thickness. Upper panels show absolute values of SFD, lower panels represent their percentage from the total root flux for each root sector.