Testing the plant pneumatic method to estimate xylem embolism resistance in stems of temperate trees
Lamarque, Laurent J
Torres-Ruiz, José M
- Publisher: Oxford University Press
(issn: 0829-318X, eissn: 1758-4469)
flow-centrifuge | Methods Paper | courbe de vulnérabilité | secondary xylem | vulnerability curve | embolism | transport xylème | modélisation hydraulique | conifers | angiosperms;bench dehydration;conifers;embolism;flow-centrifuge;pneumatic method;secondary xylem;vulnerability curve | angiosperms | pneumatic method | gymnosperme | arbre forestier | bench dehydration | analyse comparative | embolie
Abstract Methods to estimate xylem embolism resistance generally rely on hydraulic measurements, which can be far from straightforward. Recently, a pneumatic method based on air flow measurements of terminal branch ends was proposed to construct vulnerability curves by linking the amount of air extracted from a branch with the degree of embolism. We applied this novel technique for 10 temperate tree species, including six diffuse, two ring-porous and two gymnosperm species, and compared the pneumatic curves with hydraulic ones obtained from either the flow-centrifuge or the hydraulic-bench dehydration method. We found that the pneumatic method provides a good estimate of the degree of xylem embolism for all angiosperm species. The xylem pressure at 50% and 88% loss of hydraulic conductivity (i.e., Ψ50 and Ψ88) based on the methods applied showed a strongly significant correlation for all eight angiosperms. However, the pneumatic method showed significantly reduced Ψ50 values for the two conifers. Our findings suggest that the pneumatic method could provide a fast and accurate approach for angiosperms due to its convenience and feasibility, at least within the range of embolism resistances covered by our samples.