Publication Date:
2024-03-17
Description:
Results from comparative and ecological wood anatomy combined with a number of experimental studies on plant
\nhydraulics have led to a pervasive and longstanding assumption that wider-diameter vessels are more vulnerable to droughtinduced
\nembolism than narrower vessels. Although we agree that wider vessels tend to be more vulnerable than narrower vessels
\nwithin stems and within roots across most species, our current understanding of the diameter-vulnerability link does not offer a
\nmechanistic explanation for why increased vessel diameter should consistently lead to greater vulnerability or vice versa. Causes
\nof drought-induced embolism formation and spread likely operate at the nano-level, especially at gas-liquid-surfactant interfaces
\ninside intervessel pit membranes. We evaluate here new perspectives on drought-induced embolism and its key anatomical
\nand physico-chemical drivers, of which vessel diameter is one of the parameters involved, although its linkage to embolism
\nvulnerability is likely indirect. As such, the diameter-vulnerability link does not imply that species with on average wider vessels
\nare consistently more susceptible to drought-induced embolism compared to species with narrower vessels. Scientific priorities
\nfor future progress should focus on more accurate predictions of how water transport in plants is affected by drought, which
\nrequires a better mechanistic understanding of xylem network topology and biophysical processes at the nano-scale level in
\nindividual vessels that determine embolism formation and spread.
Keywords:
drought
;
embolism
;
pit membrane thickness
;
plant hydraulics
;
vessel diameter
;
wood anatomy
;
xylem networks
;
xylem sap
Repository Name:
National Museum of Natural History, Netherlands
Type:
info:eu-repo/semantics/article
Format:
application/pdf
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