Abstract
To assess the influence of witches' broom on the structure of bamboo forests, we evaluated the damage inflicted by this disease on bamboo plants and determined the species composition and species richness (number of species) of bamboo forests. Based on the degree of damage inflicted, bamboo forests were assigned to four transition phases: "normal", "infection", "dieback", and "restoration". During the transition from the normal to the dieback phase, coverage in the tree layer decreased by half and the number of species doubled as the extent of bamboo damage increased. In contrast, during the transition from the dieback to the restoration phase, coverage in the shrub layer rapidly increased tenfold, due to the regeneration of small bamboo culms, whereas the number of species decreased by half. These results indicate that witches' broom in bamboo plants has a transient positive effect on species richness in bamboo forests during the early phase of the disease but has a negative impact in the long term. After the restoration phase, bamboo forests are expected to succeed the pioneer community within a short period of time; however, over the long term, species-poor lucidophyllous forests would dominate.
