Skip Navigation


JXB Advance Access originally published online on September 25, 2003
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
54/392/2563    most recent
erg272v1
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (12)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Mayr, S.
Right arrow Articles by Dämon, B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mayr, S.
Right arrow Articles by Dämon, B.
Agricola
Right arrow Articles by Mayr, S.
Right arrow Articles by Dämon, B.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Journal of Experimental Botany, Vol. 54, No. 392, pp. 2563-2568, November 1, 2003
© 2003 Oxford University Press

Hydraulic efficiency and safety of leader shoots and twigs in Norway spruce growing at the alpine timberline

Received 30 April 2003; Accepted 15 July 2003

Stefan Mayr*, Barbara Rothart and Birgit Dämon

Institut für Botanik, Universität Innsbruck, Sternwartestr. 15, A-6020 Innsbruck, Austria

* To whom correspondence should be addressed. Fax: +43 512 507 2715. E-mail: stefan.mayr{at}uibk.ac.at
Abbreviations: dh, mean hydraulic diameter; HV, Huber value; kl, leaf specific conductivity; ks, specific hydraulic conductivity; {Psi}, water potential; {Psi}10, potential at 10% loss of conductivity; {Psi}50, potential at 50% loss of conductivity.

Xylem within trees varies in its hydraulic efficiency and safety. Trees at the alpine timberline were expected to exhibit a hydraulic architecture protecting the leader shoot from winter embolism. Hydraulic and related anatomical parameters were compared as well as seasonal courses of winter embolism in leader shoots and twigs of Norway spruce trees growing at 2000 m. Leader shoots had a 1.4-fold higher specific hydraulic conductivity (ks) as well as a 4.9-fold higher leaf specific conductivity (kl) than side twigs. Vulnerability to drought-induced embolism was lower in leader shoots with a 50% loss of conductivity occurring at a water potential ({Psi}50) 0.7 MPa lower than in twigs. Higher ks and kl were related to 1.2-fold wider tracheid diameters in leader shoots. Lower vulnerability corresponded to smaller pit dimensions but not to wood density. High ks and kl reflect the hydraulic dominance of the leader shoot, which is important for its water supply during summer. Low vulnerability protects the leader shoot from embolism during the winter season. In field measurements at the timberline during the winter of 2001/2002, conductivity losses of up to 56% were observed only in twigs while leader shoots showed little or no embolism. Results demonstrate that leader shoot xylem is both hydraulically efficient and safe.

Key words: Conductivity, conifer, hydraulic architecture, hydraulic efficiency, hydraulic safety, leader shoot, timberline, twig, vulnerability, winter embolism.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 ANN BOT (LOND)Home page
G. E. Burrows, P. F. Meagher, and R. D. Heady
An Anatomical Assessment of Branch Abscission and Branch-base Hydraulic Architecture in the Endangered Wollemia nobilis
Ann. Bot., April 1, 2007; 99(4): 609 - 623.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.