Effect of felling time related to lunar calendar on the durability of wood and bamboo
-Fungal degradation during above ground exposure test for 2 years- (Preliminary report)
K Yamamoto, S Uesugi, K Kawakami
Current study was carried out to know whether the felling time of trees and bamboos based on lunar calendar affects natural durability of felled wood-bamboo or not. Each of one sugi (Cryptomeria japonica) tree of 28 years old and one Moso bamboo (Phyllostachys heterocycla) of around 3 years old was cut 12 times between February and December in 2003. Six sets of sugi tree and bamboo were felled in a day during “Hassen” period and the other 6 sets of them were also felled in a nearby non-“Hassen” day. There is a belief that “Hassen” should be avoided to perform destructive works such as cutting trees. “Hassen” lasting 12 days based on lunar calendar appears 6 times every year. After felling sample trees and bamboos, these specimens were subject to outdoor exposure at above ground level for 2 years. Properties of specimens such as moisture contents, mould and fungal resistance were examined periodically for 2 years. There was no clear difference in the degree of mould growth on the surface between specimens felled in a “Hassen” day and those felled in a non-“Hassen” day in the same month. The felling seasons, however, influenced the growth of mould on the surface of wood and bamboo clearly, which has been traditionally known in many cases. Fungal degradation evaluated by visual observation and the depth of pin penetration using Pilodyn during 2 years exposure was not affected by not only “Hassen” or non-“Hassen” also seasons when tree and bamboo felled.
Keywords: Wood, bamboo, felling season, decay, durability, field test, Pilodyn