(A): Scheme of experimental treatments and positioning of the HFD sensors on the main experimental maple tree (Exp. 1). The lateral branch on the East side was subsequently cut twice. After the first cut a small part of the crown (indicated by the dashed line) was left and then the rest of the crown was removed with the second cut. Schemes of different possible topologies of the vascular connection between roots and branches in the stem: integrated (B) and sectored (C). Flows from root sectors on each side of the stem (Q_w and Q_e) are apportioned to two big branches (Q_m and Q_l). Flow from the eastern stem side supplies the main (Q_{m_e}) and the lateral (Q_{l_e}) branches. Flow from the western side supplies either both branches (Q_{m_w} and Q_{l_w}) in the case of integrated tree architecture (B) or only the main branch in a sectored tree (C).