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Static and dynamic bending has minor effects on xylem hydraulics of conifer branches ( P icea abies , P inus sylvestris )
Author(s) -
MAYR STEFAN,
BERTEL CLARA,
DÄMON BIRGIT,
BEIKIRCHER BARBARA
Publication year - 2014
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12307
Subject(s) - xylem , hydraulic conductivity , picea abies , hydraulics , bending , botany , chemistry , soil science , geology , materials science , biology , soil water , composite material , engineering , aerospace engineering
The xylem hydraulic efficiency and safety is usually measured on mechanically unstressed samples, although trees may be exposed to combined hydraulic and mechanical stress in the field. We analysed changes in hydraulic conductivity and vulnerability to drought‐induced embolism during static bending of P icea abies and P inus sylvestris branches as well as the effect of dynamic bending on the vulnerability. We hypothesized this mechanical stress to substantially impair xylem hydraulics. Intense static bending caused an only small decrease in hydraulic conductance (−19.5 ± 2.4% in P . abies ) but no shift in vulnerability thresholds. Dynamic bending caused a 0.4 and 0.8 MPa decrease of the water potential at 50 and 88% loss of conductivity in P . sylvestris , but did not affect vulnerability thresholds in P . abies . With respect to applied extreme bending radii, effects on plant hydraulics were surprisingly small and are thus probably of minor eco‐physiological importance. More importantly, results indicate that available xylem hydraulic analyses (of conifers) sufficiently reflect plant hydraulics under field conditions.