New insights into wood anatomy and function relationships: how Eucalyptus challenges what we already know

BAROTTO AJ; MONTEOLIVA S ; MARTINEZ MEIER A; FERNANDEZ ME; GYENGE J

Bariloche

Congreso; International Conference TOPWOOD + LIA Forestia Adapting forest ecosystems and wood products to biotic and abiotic stress; 2019

INTA

Multispecies surveys have showed that there is a weak but significant tradeoff between xylem efficiency and safety in woody species, and that there are no species occupying the space with high efficiency and high safety. Larger vessels and tracheids result in higher vulnerability to cavitation (VC) by tension in spite of there is no a direct causal relationship between VC and conduct diameter. Moreover, relationships between xylem structure and function are studied mostly at the interspecific level, with few studies considering the relationships at theintraspecific level, particularly in angiosperms. Recent studies in Quercus species have shown that trends between vessel diameter and VC observed at the interspecific level are contrary to that observed within one of the Quercus species, raising the question about the value of multispecies studies to shed light over what is adaptive within a given species. Eucalyptus species share with Quercus a xylem anatomy composed by solitary vessels sorrounded and connected to imperforate traqueary cells and parenchyma. Contrary to results in that genus, our results in four Eucalyptus species revealed that the trends observed between vessel size (mean and distribution) and VC are similar at the interspecific and intraspecific (E. globulus) levels, with no tradeoff between xylem efficiency and safety: the largest the vessels, the lower the VC. The amount of cells around vessels, quantified by different means, could be involved in this phenomenon. Also, stem wood density correlates with VC across species and within E. globulus. Trends observed in this genus challenge what we already know about xylem anatomy and function, and may help to widen our vision about the role of wood on adaptation to drought stress.