Narrow vessels cavitate first during a simulated drought in Eucalyptus camaldulensis

BARIGAH, T.S.; GYENGE JE; BARRETO MF; ROZENBERG P; FERNÁNDEZ ME

PHYSIOLOGIA PLANTARUM

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2021

0031-9317

Establishing drying-limits for mortality of different tree species and understanding the anatomical and physiological traits involved, is crucial to predict forests´ responses to climate change. The xylem of Eucalyptus camaldulensis presents a complex of solitary vessels surrounded by different imperforate tracheary elements and parenchyma that influence in a poorly known way its hydraulicfunctioning. We aimed at describing the dynamics of embolism propagation in this type of xylem, seeking for any vessel-size pattern, and unraveling the threshold of xylem embolism leading to non- recovery after drought in E. camaldulensis. We assigned potted saplings to a protracted water-stress for 70 days. We relied on colorimetric and hydraulic methods to test for links between xylem anatomy and embolism propagation in the main stem. On average, the occurrence of embolism was randomly distributed in the stem xylem, but the probability of embolized vessels was higher than predicted by chance in the narrowest vessels of individuals that experienced low to moderate water-stress. The saplings could recover from severe water-stress if their percentage loss of conductance (PLC) was