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

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