Characterization and comparison of the wood anatomical traits of plantation grown Quercus acutissima and Quercus variabilis

Abstract

Abstract Oaks are important tree species, providing essential biomaterial for the wood industry. We characterize and compare wood anatomical traits of plantation grown Quercus acutissima Carruth. and Q. variabilis Blume to provide more detailed information to understand xylem radial growth, structure, and function, as well as differences between sapwood and heartwood, to provide data relevant for tree breeding and value-added wood utilization of oak plantations in China. In this study, radial strips were collected at breast height from the main trunk of the two species. Latewood percentage and growth ring width were investigated by X-ray densitometry and a Tree Ring Analysis System, respectively. Vessel and fibre lumen diameter, vessel and fibre wall thickness, vessel density, fibre wall thickness/diameter ratio, tissue proportions, and pit membrane thickness in between vasicentric tracheids were observed with light microscopy and electron microscopy and quantified. There were significant differences in a few wood anatomical traits between the two species: vessel wall thickness and vessel lumen diameter were higher in Q. acutissima than in Q. variabilis, while higher axial parenchyma proportion in sapwood was found in Q. variabilis than in Q. acutissima. More abundant tyloses were found in heartwood than in sapwood of both species. Our work showed the intraspecific and interspecific variation of the two species. Most differences between sapwood and heartwood must be attributed to differences in cambial age during their formation.