Relationships among xylem transport, biomechanics and storage in stems and roots of nine Rhamnaceae species of the California chaparral
Article first published online: 26 MAR 2007
© The Authors (2007). Journal compilation © New Phytologist (2007)
Volume 174, Issue 4, pages 787–798, June 2007
How to Cite
Pratt, R. B., Jacobsen, A. L., Ewers, F. W. and Davis, S. D. (2007), Relationships among xylem transport, biomechanics and storage in stems and roots of nine Rhamnaceae species of the California chaparral. New Phytologist, 174: 787–798. doi: 10.1111/j.1469-8137.2007.02061.x
- Issue published online: 26 MAR 2007
- Article first published online: 26 MAR 2007
- Received: 5 December 2006 Accepted: 8 February 2007
- • Here, hypotheses about stem and root xylem structure and function were assessed by analyzing xylem in nine chaparral Rhamnaceae species.
- • Traits characterizing xylem transport efficiency and safety, mechanical strength and storage were analyzed using linear regression, principal components analysis and phylogenetic independent contrasts (PICs).
- • Stems showed a strong, positive correlation between xylem mechanical strength (xylem density and modulus of rupture) and xylem transport safety (resistance to cavitation and estimated vessel implosion resistance), and this was supported by PICs. Like stems, greater root cavitation resistance was correlated with greater vessel implosion resistance; however, unlike stems, root cavitation resistance was not correlated with xylem density and modulus of rupture. Also different from stems, roots displayed a trade-off between xylem transport safety from cavitation and xylem transport efficiency. Both stems and roots showed a trade-off between xylem transport safety and xylem storage of water and nutrients, respectively.
- • Stems and roots differ in xylem structural and functional relationships, associated with differences in their local environment (air vs soil) and their primary functions.