Wood density and anatomy of three Eucalyptus species: implications for hydraulic conductivity

Antonio J Barotto,Karen Moreno,Alejandro Martínez-Meier,Silvia Monteoliva,Natalia Tesón,Javier Gyenge,María Elena Fernández

doi:10.5424/fs/2017261-10446

Abstract

Aim of the study: To characterize wood anatomical traits of three Eucalyptus species that differ in wood density and ecological requirements, and to examine the relationships between some anatomical features, wood density, and theoretical xylem hydraulic conductivity (Ks).Area of study: We analyzed 86 trees from three sites of Argentina (Entre Ríos and Buenos Aires Provinces).Methods: The sampled trees were Eucalyptus globulus, E. grandis and E. viminalis ranging from 11 to 15 years old. One stem disc was cut from each tree to determine wood density and identify quantitative anatomical features of vessels and fibers. Vessel composition (S, size - to-number ratio, a measure of vessel size distribution) and lumen fraction (F, the total sapwood area available for water transport) were estimated. Results: E. grandis, the species with the highest growth rates, presented the highest theoretical Ks. This was associated with anatomical features such as a high density of wide vessels resulting in high F. On the other hand, E. viminalis, the species with the lowest growth rates and highest resistance to environmental stress, showed lower Ks as a result of a low density of wide vessels. These two species differed not only greatly in wood density but also in fiber characteristics. In the case of E. globulus, vessels were relatively narrow, which resulted in the lowest theoretical Ks, fibers were small, and wood density intermediate.Research highlights: F had greater influence on Ks than S. The anatomical characteristics and wood density could only partly explain the differential growth or resistance to stress of the studied species.

Highlights

Xylem structure varies along the tree at the same time that changes with age (Gartner, 1995), and has important implications for the tree functions (Zanne et al, 2010)
In order to contribute to the knowledge of potential ecological implications of different wood anatomies within a single genus, we propose to analyze some wood anatomical traits of stems of three Eucalyptus species that differ in wood density and ecological requirements
Sapwood from E. grandis and E. viminalis was sampled with an increment borer at 1.3 m above ground level along the north-south radius, while samples from E. globulus were obtained by destructive sampling at the same height

Summary

Introduction

Xylem structure varies along the tree at the same time that changes with age (Gartner, 1995), and has important implications for the tree functions (Zanne et al, 2010). Charrier et al, 2016), several authors argue that parenchyma might play a key role in embolism repair, by providing the solutes necessary to generate an osmotic gradient. Such gradient might allow water entry into cavitated vessels from nearby cells that would act Antonio J. As capacitors (Tyree et al, 1999; Hacke & Sperry, 2003; Salleo et al, 2006; Brodersen et al, 2010) It follows from this that the anatomical complexity of angiosperm wood contributes to an efficient water transport process, which depends directly on vessel characteristics and indirectly on the set of accompanying cells

Methods

Findings

Discussion

Conclusion