Detailed anatomical features of bark are used and interpreted in plant taxonomy, phylogenetics, and other areas of plant science. However, the delicate nature of bark cells, combined with the difficulty of obtaining high-quality sections and reliable data, limits the potential for utilizing and processing bark. In this study, the anatomical structure of the bark of 10 Quercus species growing in Yunnan Province, China, was characterized in detail. The results indicate that the anatomical features of the barks of 10 Quercus spp. show a certain degree of consistency. Specifically, sieve tubes are distributed in solitary elements or in small groups, mostly as compound sieve plates containing 2–8 sieve areas, suggesting that Quercus spp. may occupy a conservative evolutionary position. Additionally, for the first time, this study reports the presence of simple sieve plates in the sieve tube elements of Quercus phloem. Each sieve tube element has a companion cell on one side. The companion cell strands contain 2–7 cells. Axial parenchyma is diffuse, with parenchyma strands typically consisting of 4–7 cells; druses are present within chambered crystalliferous cells. Phloem rays are of two distinct sizes and often exhibit dilatation and sclerification, and the ray composition consists of procumbent cells. Sclerenchyma is composed of fibers and sclereids, both of which contain prismatic crystals. Most of the fibers are gelatinous fibers, which are distributed in discontinuous tangential bands of about five cells in width. Sclereids appear in clusters. The presence of sclerenchyma provides mechanical support to the bark, reducing the collapse of the phloem. Periderm usually consists of around 10–30 layers of phellem, and Quercus acutissima and Q. variabilis can reach dozens or hundreds layers. The phelloderm typically consists of from two to five layers, with Q. variabilis having up to ten or more layers. The filling tissue of lenticels in all Quercus species is nonstratified (homogeneous) and largely nonsuberized. Overall, this study enriches our comprehension of Quercus bark anatomy, elucidating evolutionary patterns, functional adaptations, and ecological ramifications within this significant botanical genus.

This study takes the wooden components of the different parts of the ancient buildings at the site of the Zhuangzishang Conference as the object of study, and investigates the deterioration state of the different wood components. To assess their degree of degradation, the wood anatomy, basic density (BD), maximum water content (MWC), cell wall major components, X-ray diffraction (XRD), infrared spectroscopy (IR), and thermogravimetry (TG) were used to compare the samples of new and old wood from the same species. The window (W) was identified by microscopic characterization as cypress (Cupressus sp.), the footing beam (FB) and the weatherboard (WB) as pine (Pinus spp.), the purlin (P) and the column (C) as Chinses fir (Cunninghamia spp.), and the floor (F) as spruce (Picea sp.). In terms of their physical properties, the old wood had a lower basic density of 2.58%–38.19%, a lower air-dry density of 2.87%–39.81%, and a higher maximum moisture content of 8.52%–41.38% compared to the reference wood. The degradation of the FB, which has been subjected to moisture and sunlight, and the P, which has been subjected to termite damage, was greater than that of their conspecifics. The integrated holocellulose of the ancient wood was 3.34%–16.48% less, and the hemicellulose was 1.6%–21.92% less compared to that of the reference wood, and the lignin was 1.32%–25.07% more. The XRD results showed that the crystallinity of the cellulose was greater in the different species of ancient wood compared to the control wood, which was caused by the decrease in the amorphous zones of the hemicellulose and cellulose in the ancient wood. The IR indicated that the degradation of cellulose and hemicellulose occurred in the old wood of all species, from the new lignin uptake peaks in the UV-exposed W, FB, and WB compared to the control timber. The pyrolytic behavior of the ancient and control timber is mainly related to the degradation of the tree species and the ancient wood holocellulose. These results show that the differences in the wooden components of the different parts of the ancient buildings at the Zhuangzishang Conference site are mainly related to the species of trees used in the components, and are secondly related to the location of the ancient wood members, which provides useful information for the protection and repair of the ancient buildings at the site.