Uncoated sugi (Japanese cedar, Cryptomeria japonica D.Don) heartwood or sugi coated with penetrating or film-forming coating were exposed to natural weathering. Further, three types of accelerated weathering tests were performed. One test was conducted under an artificial sunlight irradiance of 60 W/m² based on JIS K 5600-7-7 (filtered xenon-arcradiation, method 1, cycle A). The remaining two tests were performed at 105 W/m² (1.75-fold) and 150 W/m² (2.50-fold). The color difference, water repellency index, and gloss of the specimens were evaluated as indicators of weathering. We observed that the changes in these weathering indicators were accelerated by increasing the irradiance; however, the effects differed among various indicators and depended on the coating types. The changes in color difference, water repellency index, and gloss during these accelerated weathering tests did not significantly differ from those observed during natural weathering.

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Comparative genomics on wood rotting fungi suggested that the evolution from ancestral white-rot fungi to brown-rot fungi, which are at least phylogenetically classified into the four orders of Boletales, Dacrymycetes, Gloeophyllales, and Polyporales, occurred independently multiple times. In the present study, three brown-rot fungi (Fomitopsis palustris, F. pinicola, and Wolfiporia cocos) and a white-rot fungus (Trametes versicolor) were used to investigate wood decay manner in Polyporales. Wood (Cryptomeria japonica) blocks decayed by the fungi above were analyzed by X-ray diffraction and Fourier transform infrared spectroscopy analyses. As a result, cellulose crystallinities and infrared spectra were significantly different between white-rot and brown-rot fungi. Multivariate analysis of the infrared spectroscopy data showed the somewhat different plot patterns between brown-rot species.

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I measured the temperature and relative humidity of the neighborhood of floor bottom and dirt floor of the traditional wooden house without the resident in Nara. As a result, both the temperature and the relative humidity of there became higher in the rainy season, in the summer, in the first fall, and understood that it was easy to be with the environment where damp mold was easy to grow. It is thought that moisture from the floor lower soil and a dirt floor influences it.
When outside temperature decreases after a fall, it becomes less than a water condensation near a dirt floor, it was understood that water condensation was more likely to become easy to be generated on the border with the outdoors. In addition, it was revealed that it was unlikely to be the growth of the damp mold because temperature decreased during this period.
Therefore, in time from the rainy season with many typhoons from the beginning of September to the middle, it can say that it is particularly important to fix the environment of the material neighborhood in controlling biodeterioration of the wood.

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