Seasonal and height-dependent fluctuation of starch and free glucose contents in moso bamboo (Phyllostachys pubescens) and its relation to attack by termites and decay fungi

The potential of termite (Coptotermes formosanus Shiraki) and fungal attacks [Fomitopsis palustris (Berkeley et Curtis) Murrill (FFPRI 0507) and Trametes versicolor (L. ex Fr.) Quel (FFPRI 1030)] against moso bamboo (Phyllostachys pubescens Mazel) were evaluated with regard to the seasonal and height-dependent changes of the free glucose and starch contents, which were measured by a newly developed method. The free glucose contents were generally lower in autumn and winter than in spring and summer, whereas the lowest starch contents were obtained in August, and the contents increased almost linearly up to February and March. In terms of the height-dependent fluctuation, the free glucose contents tended to decrease as the sampling heights increased. There was no special correlation between the free glucose or starch contents and the consumption by termites, even though higher mortalities were obtained in the bamboo-fed termites than in the wood-fed termites. However, a positive correlation between the free glucose contents and mass losses of the samples at 4-m and 8-m heights from the bottom by the decay fungi was observed. For starch, no influence on fungal attack was found.