| Abstract: | Abstract. In southwestern Tokyo the area covered by bamboo forest has expanded by a factor of 2.7 over the last 26 years. This has mainly been due to bamboo (Phyllostachyspubescens) invading secondary broad-leaved forests, probably after these were abandoned. In the first stage, bamboo sprouts develop from rhizomes at the periphery of the broad-leaved forest and then grow very quickly into young culms. In the next phase culm density increases annually, while the existing broad-leaved trees gradually lose their vitality and die. Finally, the broad-leaved forest is completely replaced by bamboo forest. The competitive ability of bamboo, based on its morphological and growth features, is suggested as the causal factor for the invasion: (1) bamboo can invade a neighboring broad-leaved forest by its vigorous rhizomes; (2) young bamboo culms can break through the canopy of broad-leaved trees; (3) bamboo quickly forms a crown in or above the canopy of the broad-leaved forest; (4) bamboo is very tolerant of strong wind and heavy snow accumulation; (5) bamboo culms, being very pliable during strong wind mechanically damage neighbouring broad-leaved trees. |
