Modeling lumber recovery in relation to selected tree characteristics in jack pine using sawing simulator Optitek

Abstract

End uses and product recovery are important considerations in forest management decision-making. This study intended to develop general tree-level lumber volume recovery models for jack pine. A sample of 154 jack pine trees collected from natural stands was scanned to obtain 3-D stem geometry for sawing simulation under two sawmill layouts, a stud mill and a random mill with optimized bucking, using sawing simulator Optitek. Three model forms were chosen to describe the quantitative relationship between simulated lumber volume recovery and tree characteristics. It was found that lumber volume recovery of individual trees from both sawmills could be well estimated from DBH using a second-order polynomial equation. Adding tree height into the model resulted in a small but significant improvement in the goodness of the model. Adding tree taper into the model that already included DBH and tree height no longer improved the goodness significantly. The power function form involving only DBH or both DBH and tree height as variables was also found to be suitable for the stud mill; exponential forms were least suitable. The second-order polynomial model with DBH alone was the most suitable model when inventory records DBH only, while the second-order polynomial model and the power model involving two variables (DBH and tree height) for the random mill and the stud mill, respectively, were better when both DBH and tree height are available. © INRA, EDP Sciences, 2005.