Empirical statistical model for predicting wood properties of Paulownia fortunie. Part 1: Physical and biometrical properties

Abstract

This paper describes the development of model to predict the within-tree variation of wood density, shrinkage, fiber length, fiber diameter and cell wall thickness from pith-to-bark and bottom-to-top, using
data collected from a 13-year-old paulownia (Paulownia fortunie) stand where trees were planted in an experimental plantation in Iran. The sample disks were taken from each tree to examine the wood
density, shrinkage, fiber length, fiber diameter and cell wall thickness variation from pith to bark at 5, 25, 50 and 75% of the total tree height. The study was laid out in a randomized complete block design.
Linear prediction model were developed using longitudinal direction (bottom-to-top) and radial direction (pith-to-bark) indices as explanatory variables. The results indicated that, the wood density, shrinkage,
fiber length, fiber diameter and cell wall thickness, considerably changes from pith to bark and from the base upwards. Based on the final model, it was found that the physical and biometrical properties were significantly influenced by longitudinal and radial directions. The model equation were based on the model used to describe the within-tree variation in the wood density, shrinkage, fiber length, fiber diameter and cell wall thickness of Paulownia, and is functions of radial and longitudinal directions.