Influence of anatomical characteristics on the physical properties of wood from Cerrado species

Summary The secondary xylem is a complex tissue whose cell proportions and structures alter wood properties, which are essential for characterizing a species for final use. Correlating wood anatomy with technological characterization is important to appropriately qualify materials, especially for Cerrado species, which are typically studied for energy purposes. Therefore, this study analyzed the influence of wood anatomy on wood density, volumetric shrinkage, and anisotropy of four Cerrado woody species. Thirty measurements of different anatomical traits and cell fractions were submitted to Redundancy Analysis (RDA), Extra-Trees Regressor with cross-validation, and partial correlation. These analyses showed that species with a lower proportion of axial parenchyma cells, thicker ray cell walls, a higher proportion of fiber wall and vessel lumen, longer vessels, and fibers with narrower lumens presented high wood density. Species with thick axial parenchyma cell walls, longer vessels and fibers, and a higher proportion of fiber lumen had high shrinkage, whereas a higher percentage of multiple vessels, greater investment in fiber walls, vessel-ray pits and more rays per millimeter decreased shrinkage. Finally, longer fiber and vessel lengths, taller rays in low frequency, and thick-walled fibers are associated with higher wood anisotropy. On the contrary, higher fiber wall proportion and lower rays decreased the anisotropy of wood. Thus, the structural organization of wood anatomical characters directly affects physical properties, demonstrating that the relative proportion of cell walls, lumen sizes and parenchyma cells are definitive drivers of wood technological behavior.