Modeling of radial variations of wood properties in naturally regenerated trees of Betula platyphylla grown in Selenge, Mongolia

Journal of Wood Science

Official Journal of the Japan Wood Research Society

Table 4 Annual ring number at the boundary between the core wood and outer wood as determined by the regression formula based on the best model for wood fiber length in each tree

u_i, random effect parameter at individual tree level. Wood fiber length at every annual ring was estimated by Model II (y_ij = β₀ ln (x_ij) + β₁ + u_i + e_ij; β₀ = 0.158, β₁ = 0.592) listed in Table 2. Annual ring number at the boundary was regarded as the annual ring number at which the annual increment of wood fiber length became less than 1%