The functional implications of tracheary connections across growth rings in four northern hardwood trees

Publication Title

Annals of Botany

Document Type

Article

Department or Program

Biology

Publication Date

9-24-2019

Keywords

Acer rubrum, connectivity, diffuse porous, earlywood, Fagus grandifolia, Fraxinus americana, growth rings, hydraulics, latewood, Quercus rubra, ring porous, xylem

Abstract

Background and aims: Deciduous angiosperm trees transport xylem sap through trunks and branches in vessels within annual growth rings. Utilizing previous growth rings for sap transport could increase vessel network size and redundancy but may expose new xylem to residual air embolisms in the network. Despite the important role of vessel networks in sap transport and drought resistance, our understanding of cross-ring connections within and between species is limited. Methods: We studied cross-ring connections in four temperate deciduous trees using dye staining and X-ray microcomputed tomography (microCT) to detect xylem connectivity across growth rings and quantify their impact on hydraulic conductivity. Key results: Acer rubrum and Fraxinus americana had cross-ring connections visible in microCT but only A. rubrum used previous growth rings for axial sap flow. Fagus grandifolia and Quercus rubra, however, did not have cross-ring connections. Accounting for the number of growth rings that function for axial transport improved hydraulic conductivity estimates. Conclusions: These data suggest that the presence of cross-ring connections may help explain aspects of whole-tree xylem sap transport and should be considered for plant hydraulics measurements in these species and others with similar anatomy.

Comments

Original version is available from the publisher at: https://doi.org/10.1093/aob/mcz076

PubMed ID

31330537

Copyright Note

© The Author(s) 2019. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved.

This document is currently not available here.

Share

COinS