Consistent decrease in conifer embolism resistance from the stem apex to base resulting from axial trends in tracheid and pit traits

• DOI: 10.3389/fpls.2024.1414448
• Publication Date: 2024-06-25T04:48:36Z
• Authors: Dario Zambonini; Tadeja Savi; Sabine Rosner; Giai Petit
• Keywords: Apex (geometry); Tracheid; Base (topology)

Introduction Drought-induced embolism formation in conifers is associated with several tracheid and pit traits, which vary parallel from stem apex to base. We tested whether this axial anatomical variability a progressive variation vulnerability along the Methods assessed hydraulic diameter ( Dh ), mean membrane area PMA ) xylem pressure at 50% loss of conductivity P50 on longitudinal segments extracted different distances DFA Picea abies an Abies alba tree. Results In both trees, scaled 0.2 . varied for more than 3 MPa treetop base, according scaling - -0.2 The largest , occurred <1.5 m. isometrically (exponent b =1.2). Pit traits proportionally lumen diameter. Discussion conclusions Apex-to-base trends variations P50, suggest strong structure-function relationship that influenced by Although effect has not been extensively explored previously, we propose analyzing between could be crucial comprehensive assessment individual level.