Below-ground hydraulic conductance is a function of environmental conditions and tree size in Scots pine

J. Martínez-Vilalta, E. Korakaki, Dirk Vanderklein, M. Mencuccini

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

1. Variations in water tension in a transpiring tree cause elastic changes in stem diameter. To better understand the dynamics of these variations, stem diameter changes and sap flow rates were monitored simultaneously in trees from two Scots pine chronosequences in Scotland. 2. Tree below-ground hydraulic conductance (kbg) was estimated from the relationship between leaf-specific sap flow rates and the difference between stem and soil water potentials estimated from diameter variations in the stem. 3. In a given tree, kbg varied both within and among days, with conductance increasing as a function of sap flow and evaporative demand. These patterns could be explained in terms of a composite model of root water transport and possible changes in the gating of aquaporins. 4. We interpreted these trends of increasing kbg with evaporative demand as a mechanism to enhance the ability of trees to control leaf water potential and keep it within physiologically acceptable limits, with potential implications for our general understanding of plant water relations, and for the estimation and modelling of ecosystem water fluxes. 5. Across trees, kbg declined with increasing tree age/size, but the proportional contribution of below-ground to whole-tree hydraulic resistance also declined. This is consistent with an increase in below-ground carbon allocation in old/tall trees and a partial acclimation of tall trees to hydraulic limitations. It is argued that these trends have to be considered when discussing the importance of tree height for water transport and growth.

Original languageEnglish
Pages (from-to)1072-1083
Number of pages12
JournalFunctional Ecology
Volume21
Issue number6
DOIs
StatePublished - 1 Nov 2007

Fingerprint

Pinus sylvestris
fluid mechanics
environmental conditions
hydraulics
environmental factors
sap flow
stem
stems
water
plant water relations
plant-water relations
aquaporins
soil water potential
tree age
chronosequences
leaf water potential
biomass allocation
chronosequence
Scotland
acclimation

Keywords

  • Root water transport
  • Sap flow
  • Stem diameter variations
  • Tree height
  • Variable hydraulic resistance

Cite this

Martínez-Vilalta, J. ; Korakaki, E. ; Vanderklein, Dirk ; Mencuccini, M. / Below-ground hydraulic conductance is a function of environmental conditions and tree size in Scots pine. In: Functional Ecology. 2007 ; Vol. 21, No. 6. pp. 1072-1083.
@article{8abab718ab7b47728683569c0b3c7e3a,
title = "Below-ground hydraulic conductance is a function of environmental conditions and tree size in Scots pine",
abstract = "1. Variations in water tension in a transpiring tree cause elastic changes in stem diameter. To better understand the dynamics of these variations, stem diameter changes and sap flow rates were monitored simultaneously in trees from two Scots pine chronosequences in Scotland. 2. Tree below-ground hydraulic conductance (kbg) was estimated from the relationship between leaf-specific sap flow rates and the difference between stem and soil water potentials estimated from diameter variations in the stem. 3. In a given tree, kbg varied both within and among days, with conductance increasing as a function of sap flow and evaporative demand. These patterns could be explained in terms of a composite model of root water transport and possible changes in the gating of aquaporins. 4. We interpreted these trends of increasing kbg with evaporative demand as a mechanism to enhance the ability of trees to control leaf water potential and keep it within physiologically acceptable limits, with potential implications for our general understanding of plant water relations, and for the estimation and modelling of ecosystem water fluxes. 5. Across trees, kbg declined with increasing tree age/size, but the proportional contribution of below-ground to whole-tree hydraulic resistance also declined. This is consistent with an increase in below-ground carbon allocation in old/tall trees and a partial acclimation of tall trees to hydraulic limitations. It is argued that these trends have to be considered when discussing the importance of tree height for water transport and growth.",
keywords = "Root water transport, Sap flow, Stem diameter variations, Tree height, Variable hydraulic resistance",
author = "J. Mart{\'i}nez-Vilalta and E. Korakaki and Dirk Vanderklein and M. Mencuccini",
year = "2007",
month = "11",
day = "1",
doi = "10.1111/j.1365-2435.2007.01332.x",
language = "English",
volume = "21",
pages = "1072--1083",
journal = "Functional Ecology",
issn = "0269-8463",
publisher = "Wiley-Blackwell Publishing Ltd",
number = "6",

}

Below-ground hydraulic conductance is a function of environmental conditions and tree size in Scots pine. / Martínez-Vilalta, J.; Korakaki, E.; Vanderklein, Dirk; Mencuccini, M.

In: Functional Ecology, Vol. 21, No. 6, 01.11.2007, p. 1072-1083.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Below-ground hydraulic conductance is a function of environmental conditions and tree size in Scots pine

AU - Martínez-Vilalta, J.

AU - Korakaki, E.

AU - Vanderklein, Dirk

AU - Mencuccini, M.

PY - 2007/11/1

Y1 - 2007/11/1

N2 - 1. Variations in water tension in a transpiring tree cause elastic changes in stem diameter. To better understand the dynamics of these variations, stem diameter changes and sap flow rates were monitored simultaneously in trees from two Scots pine chronosequences in Scotland. 2. Tree below-ground hydraulic conductance (kbg) was estimated from the relationship between leaf-specific sap flow rates and the difference between stem and soil water potentials estimated from diameter variations in the stem. 3. In a given tree, kbg varied both within and among days, with conductance increasing as a function of sap flow and evaporative demand. These patterns could be explained in terms of a composite model of root water transport and possible changes in the gating of aquaporins. 4. We interpreted these trends of increasing kbg with evaporative demand as a mechanism to enhance the ability of trees to control leaf water potential and keep it within physiologically acceptable limits, with potential implications for our general understanding of plant water relations, and for the estimation and modelling of ecosystem water fluxes. 5. Across trees, kbg declined with increasing tree age/size, but the proportional contribution of below-ground to whole-tree hydraulic resistance also declined. This is consistent with an increase in below-ground carbon allocation in old/tall trees and a partial acclimation of tall trees to hydraulic limitations. It is argued that these trends have to be considered when discussing the importance of tree height for water transport and growth.

AB - 1. Variations in water tension in a transpiring tree cause elastic changes in stem diameter. To better understand the dynamics of these variations, stem diameter changes and sap flow rates were monitored simultaneously in trees from two Scots pine chronosequences in Scotland. 2. Tree below-ground hydraulic conductance (kbg) was estimated from the relationship between leaf-specific sap flow rates and the difference between stem and soil water potentials estimated from diameter variations in the stem. 3. In a given tree, kbg varied both within and among days, with conductance increasing as a function of sap flow and evaporative demand. These patterns could be explained in terms of a composite model of root water transport and possible changes in the gating of aquaporins. 4. We interpreted these trends of increasing kbg with evaporative demand as a mechanism to enhance the ability of trees to control leaf water potential and keep it within physiologically acceptable limits, with potential implications for our general understanding of plant water relations, and for the estimation and modelling of ecosystem water fluxes. 5. Across trees, kbg declined with increasing tree age/size, but the proportional contribution of below-ground to whole-tree hydraulic resistance also declined. This is consistent with an increase in below-ground carbon allocation in old/tall trees and a partial acclimation of tall trees to hydraulic limitations. It is argued that these trends have to be considered when discussing the importance of tree height for water transport and growth.

KW - Root water transport

KW - Sap flow

KW - Stem diameter variations

KW - Tree height

KW - Variable hydraulic resistance

UR - http://www.scopus.com/inward/record.url?scp=36248944147&partnerID=8YFLogxK

U2 - 10.1111/j.1365-2435.2007.01332.x

DO - 10.1111/j.1365-2435.2007.01332.x

M3 - Article

AN - SCOPUS:36248944147

VL - 21

SP - 1072

EP - 1083

JO - Functional Ecology

JF - Functional Ecology

SN - 0269-8463

IS - 6

ER -