Effects of cambial age and flow path-length on vessel characteristics in birch

摘要: The distribution of vessels in broadleaf timber, is directly related to water transport efficiency and safety. Here, I tested the hypothesis that vessel characteristics depend on cambial age (CA) flow path-length (PL) within tree rather than solely CA by measuring hydraulic diameter (VD), frequency (VF), theoretical specific conductivity (k s), implosion resistance (VIR) every growth ring birch (Betula platyphylla Roth.) root, trunk, branch samples. effects PL were analyzed using a linear mixed model. Differences are significant between CA, PL, interaction PL. VD decreased linearly VF increased nonlinearly with explained 59.3 67.3 % longitudinal variation VF, respectively. k s VIR 25.6 43.3 % VIR, Radial changes evident above ground, increased, for first 10–20 years remained constant thereafter. s exhibited logarithmic increase decrease CA. Variable radial patterns observed below ground. 30.9–98.8 %, 23.7–96.9 %, 42.9–96.8 %, 50.9–98.5 % VD, s, results suggest characteristic determined While growing, trees adjust their maximize ensure mechanical