Skip to Main Content
Coordination of leaf and stem water transport properties in tropical forest treesAuthor(s): Frederick C. Meinzer; David R. Woodruff; Jean-Christophe Domec; Guillermo Goldstein; Paula I. Campanello; Genoveva M. Gatti; Randol Villalobos-Vega
Source: Oecologia: Vol 156 pgs 31-41
Publication Series: Miscellaneous Publication
PDF: Download Publication (0 B)
DescriptionStomatal regulation of transpiration constrains leaf water potential (ψ l) within species-specific ranges that presumably avoid excessive tension and embolism in the stem xylem upstream. However, the hydraulic resistance of leaves can be highly variable over short time scales, uncoupling tension in the xylem of leaves from that in the stems to which they are attached. We evaluated a suite of leaf and stem functional traits governing water relations in individuals of 11 lowland tropical forest tree species to determine the manner in which the traits were coordinated with stem xylem vulnerability to embolism. Stomatal regulation of ψL was associated with minimum values of water potential in branches (ψbr ) whose functional significance was similar across species. Minimum values of ψbr coincided with the bulk sapwood tissue osmotic potential at zero turgor derived from pressure-volume curves and with the transition from a linear to exponential increase in xylem embolism with increasing sapwood water deficits. Branch xylem pressure corresponding to 50% loss of hydraulic conductivity (P50) declined linearly with daily minimum ψbr in a manner that caused the difference between ψbr and P50 to increase from 0.4 MPa in the species with the least negative ψ br to 1.2 MPa in the species with the most negative ψbr. Both branch P50 and minimum ψbr increased linearly with sapwood capacitance (C) such that the difference between ψbr and P 50 an estimate of the safety margin for avoiding runaway embolism, decreased with increasing sapwood C. The results implied a trade-off between maximizing water transport and minimizing the risk of xylem embolism, suggesting a prominent role for the buffering effect of C in preserving the integrity of xylem water transport. At the whole-tree level, discharge and recharge of internal C appeared to generate variations in apparent leaf-specific conductance to which stomata respond dynamically.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationMeinzer, Frederick C.; Woodruff, David R.; Domec, Jean-Christophe; Goldstein, Guillermo; Campanello, Paula I.; Gatti, Genoveva M.; Villalobos-Vega, Randol. 2008. Coordination of leaf and stem water transport properties in tropical forest trees. Oecologia: Vol 156 pgs 31-41
KeywordsCapacitance, Stomata, Transpiration, Turgor, Xylem vulnerability
- Xylem hydraulic safety margins in woody plants: coordination of stomatal control of xylem tension with hydraulic capacitance
- Diurnal and seasonal variation in root xylem embolism in neotropical savanna woody species: impact on stomatal control of plant water status.
- Xylem heating increases vulnerability to cavitation in longleaf pine
XML: View XML