Intégration des voies de transport de l’eau dans un érable : réponses du flux de sève à une ablation de branche

Abstract

• It has been known for a long time that sectored and integrated patterns of vascular systems exist in different species and even within the same tree, depending on its age and history. However, very few publications consider the topology of the vascular pathways between roots and branches.• Some results on this important aspect of the vascular system are presented in this paper. They have been obtained with adult maple trees by directly studying the water movement in the stem and root xylem with the heat field deformation (HFD) method for sap flow measurements.• Multi-point HFD sensors were installed at different heights of a Norway maple tree ( Acer platanoides L.) along its stem axis. Single-point HFD sensors were installed in three small lateral roots of another sample maple. Experimental treatments (branch severing) triggered changes in sap movement in the stem and root sapwood.• The sample trees belong to the group with an integrated transport system (“integrated pipes”), sharing stem space on both sides of the tree to supply two large parts of the crown with water from each root sector. Nevertheless, conducting pathways had their autonomy for axial transport and the pipe model theory describes the vascular system of the studied trees well. Thus, the integration of axial transport in the stem xylem should presumably occur through the cross-grained network of axial vessels.