Study on the Identification and the Extent of Decay of the Wooden Components in the Xichuan Guild Hall Ancient Architectures

In the present study, the microscopic structures of the wooden components in the Xichuan Guild Hall were observed through the bright-field microscope to identify the tree species. The extent of decay of these wooden components was observed using polarized light and fluorescence microscopes, respectively. The results are as follows: (1) Sample Nos. 1, 2, 4, 5, 7, and 8 belonged to hemor woods (Schimaspp.), and sample Nos. 3 and 6 belonged to red oak woods (Quercus rubra). (2) Almost no brightness of crystalline cellulose birefringence (BCCB) was found in S layers of wood fibres of the fungal-decayed hemor woods, indicating an obvious decomposition of the celluloses in S layers. The brightness of fluorescence (BF) of all cell walls was also lower, indicating that lignin in cell walls was seriously decomposed by the decay fungi. (3) Almost no BCCB was found in vessels and S layers of wood fibres of the fungal-decayed red oak woods, indicating that celluloses were seriously decomposed. The BF of cell walls of vessels and CML layer of wood fibres was evident, indicating that lignin was abundant in cell walls of vessels and CML layer of wood fibres.