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The importance of xylem constraints in the distribution of conifer species


Brodribb, TJ and Hill, RS, The importance of xylem constraints in the distribution of conifer species, New Phytologist, 143, (2) pp. 365-372. ISSN 0028-646X (1999) [Refereed Article]

DOI: doi:10.1046/j.1469-8137.1999.00446.x


Vulnerability of stem xylem to cavitation was measured in 10 species of conifers using high pressure air to induce xylem embolism. Mean values of air pressure required to induce a 50% loss in hydraulic conductivity (φ50) varied enormously between species, ranging from a maximum of 14.2 ± 0.6 MPa (corresponding to a xylem water potential of -14.2 MPa) in the semi-arid species Actinostrobus acuminatus to a minimum of 2.3 ± 0.2 MPa in the rainforest species Dacrycarpus dacrydioides. Mean φ50 was significantly correlated with the mean rainfall of the driest quarter within the distribution of each species. The value of φ50 was also compared with leaf drought tolerance data for these species in order to determine whether xylem dysfunction during drought dictated drought response at the leaf level. Previous data describing the maximum depletion of internal CO2 concentration (c(i)) in the leaves of these species during artificial drought was strongly correlated with φ50 suggesting a primary role of xylem in effecting leaf drought response. The possibility of a trade-off between xylem conductivity and xylem vulnerability was tested in a sub-sample of four species, but no evidence of an inverse relationship between φ50 and either stem-area specific (K(a)) or leaf-area specific conductivity (K1) was found.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the environmental sciences
UTAS Author:Brodribb, TJ (Professor Tim Brodribb)
UTAS Author:Hill, RS (Professor Bob Hill)
ID Code:17501
Year Published:1999
Web of Science® Times Cited:136
Deposited By:Plant Science
Deposited On:1999-08-01
Last Modified:2011-08-05

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