Stem, branch, and root wood anatomy of black oak (Quercus velutina Lam)
Three Iowa-grown black oak (Quercus velutina Lam.) trees, 16.5, 16.5, and 18.0 cm (6.5, 6.5, and 7.1 inches) diameter at breast height (1.37 meters or 4.5 feet) were harvested by excavating the central stump/root system to a 91.4 cm (3-foot) radius. The first two trees were stand-grown, and the third was open-grown. All roots greater than 1.27 cm (0.5 inch) diameter were collected. Green biomass and moisture content of leaf, twig, branch, stem, and stump/root components were measured. Complete-tree biomass was 245.18, 243.32, and 316.7 Kg for the three trees. The stump/root comprised 27 percent of oven-dry complete-tree biomass. Moisture content decreased from roots to twigs;There was no significant difference in wood plus bark or wood specific gravity (SG) between the three trees. Locations within trees were significantly different. Wood specific gravity decreased from branch to stem to oblique root to lateral root;Fibers were longest in the lower stem (1.04 mm), followed by lateral (1.01) and oblique (0.99) roots (statistically equal), upper stem (0.96), and branches (0.76 mm). Fiber radial diameter was greatest in lateral and oblique roots, followed by stem and branch. Oblique roots had the largest fiber lumen diameter, followed by lateral roots, stem, and branch. Fiber double tangential wall thickness was ranked as lateral root, oblique root, stem, and branch;Branches had the highest vessel volume followed by stem, oblique roots, and lateral roots. Ray percentage was greatest in lateral roots, followed by oblique roots, with stem and branch smallest. Branches and stems had the largest fiber proportion; oblique and lateral roots had less. Axial parenchyma and vasicentric tracheid percentages were greatest in the stem with oblique root, branch, and lateral root components lower;Rather than having a ring porous structure, root wood had a semi-ring porous structure with pores often arranged in radial streams, clusters, or dendritic patterns. One other important difference was that vessel-parenchyma pitting was scalariform in the root. Anatomical features are illustrated with 125 light and scanning electron micrographs.