Predicting wood and tracheid properties of Scots pine

Abstract

Models were developed for predicting the proportion of latewood, wood density, tracheid length, tracheid width, and the ratio of cell wall thickness to tracheid width in individual annual rings of Scots pine (Pinus sylvestris L.). The models needed to be applicable as a part of a stand growth simulation system, which is based on growth models at the tree level. Data were collected from long-term thinning, thinning-fertilisation, and precommercial thinning experiments on mineral soil and drained peatland in southern and central Finland. The wood and tracheid properties were related to radial increment rate and distance from the pith outwards. An increased increment rate, caused by the different treatments and environmental conditions, resulted in similar types of changes in the wood and tracheid properties irrespective of the factors promoting radial increment. Although most of the average values of the properties were predicted unbiased, there were large random variations between individual trees and annual rings. The fixed parts of the models accounted for the following percentages of the variation: latewood proportion, 42%, wood density, 35%, tracheid length, 84%, tracheid width, 44%, and cell wall percentage, 29%. Incorporating the models for wood and tracheid properties into forest management planning systems enables estimates for the conversion of different silvicultural regimes into internal stem structure and wood quality.