Production of regional single-entry volume tables and development of raw wood product mix model for Ontario

Abstract

Regional single-entry volume equations for northern Ontario were derived based on the standard volume equations by Honer et al. A site stratification methodology was employed to derive localized regional height-diameter equations. Using this method, the variation of height prediction for a given species within a region was greatly reduced. Thus, site specific equations were derived for each species. For stand data lacking tree height information, the exponential function: Height = b1 x exp (b2/Dbh) proved best for height prediction. This model was used to substitute height in standard volume equations. In addition to the total volume and gross merchantable volume based on top diameter and stump height, the net merchantable volume based on age was also derived. Stem profile equations were also fitted and used to model wood product mixes. The results showed that Max and Burkhart's model was the most accurate and precise model in predicting top diameters and section heights along the bole, while the model by Demaerschalk performed better for volume prediction. These stem profile equations demonstrated maximum flexibility in dealing with the wood product mixes. By combining the stem profile models and the single-entry volume equations, a modelling system was developed to estimate wood product mixes for stands based on dbh distributions. The wood product mix model developed can be used at both the tree level and stand level. A Fortran program was written to facilitate the calculations for modelling the combinations of wood product mixes at the stand level.