Multivariate Morphological Analysis of Indigenous and Hybrid Poplar Strands for Oriented Strand Board and Laminated Strand Lumber Production

Geometric uniformity in lignocellulosic furnish plays a central role in determining the mechanical reliability and density stratification of engineered wood products. This study presents a comprehensive morphological assessment of wood strands produced from indigenous poplar (Populus nigra L.) and hybrid poplar (Populus × euramericana (Dode) Guinier) strands under full industrial flaking conditions. A total of 600 strands were characterized for weight, length, width, and thickness and analyzed using a multivariate statistical framework integrating Principal Component Analysis (PCA) and bivariate correlation modeling. Despite being processed to the same nominal target length (120 mm), the two provenances exhibited markedly different dimensional behaviors. Hybrid poplar strands were substantially heavier (mean 0.536 g vs. 0.291 g) and slightly thicker on average, while indigenous strands were marginally wider; strand length did not differ significantly between provenances (p = 0.354). PCA applied to four variables (weight, length, width, and mean thickness) revealed that weight and width were the dominant contributors to PC1 (57.0% of total variance), enabling clear separation of the two provenances into distinct multivariate clusters. These findings indicate that hybrid furnish, due to its coarser and more variable geometry, may require enhanced mat densification during hot pressing to minimize internal voids and achieve a stable vertical density profile (VDP). The dataset and analytical approach presented here provide actionable insights for optimizing flaker calibration, strand classification, and resin dosing strategies in the production of Oriented Strand Board (OSB) and Laminated Strand Lumber (LSL), particularly when integrating fast-growing hybrid poplar resources into industrial manufacturing lines.