Prediction of graded lumber yields from graded trees in West Tennessee

During recent years disparities have occurred between the prices paid for lumber of different grades, especially for highly desirable species like oak. High grade oak lumber, i.e. FAS lumber, today sells in excess of $1500.00 per 1000 board feet and the lowest grade, i.e. 3B, rarely returns more than $350.00 per 1000 board feet. Prices paid for standing timber have increased accordingly thus creating a real need for a comprehensive understanding of tree-to-lumber-by-grade yield. Such an understanding will allow sawmillers to make informed purchases of standing timber.

This research attempts to develop a method to predict lumber yields by grade (Lumber-grade yields) from graded standing trees. The independent variable was tree volume based on the Doyle log rule and Girard form class 78. Actual lumber-grade yields were the dependent variables. The regression analyses, using 35 red oak and 36 cherrybark red oak, were not statistically significant. The ratios of lumber-grade yields to tree volume provided the most useful information.

Suggestions are made for necessary timber inventory procedure, required computer hardware and software to manipulate data, and a method of upgrading the system.