Quality Indexes for Oak Sawlogs Based on Green Lumber Grade Yields

Abstract

Abstract Quality Indexes for red oak (Quercus rubra) and white oak (Quercus alba) logs were established using multivariate regression models developed by the US Department of Agriculture (USDA) Forest Service that predicted green 4/4 lumber grade yields from hardwood sawlogs. Past Quality Indexes were based on air-dried lumber grade yields, but these yields can be affected by mill-specific factors. Considering green lumber as the finished product isolated the drying process and any subsequent changes in lumber product value from the analysis. Lumber grades were consistent with National Hardwood Lumber Association specifications, while log grades were based on the USDA Forest Service grading rules. Input data into the models included log scaling diameter, log length, and percent scaling defect. Green lumber grade yields were then used along with price relatives developed from 5-year lumber grade price averages (nominal) to develop Quality Indexes for each species. Two applications of the Quality Index are illustrated.