Abstract
This study investigated the growth response of a specific alien species, Hydrocotyle ranunculoides L. f., to differences in water current and scraping on and below the soil surface. Furthermore, growth characteristics of creeping stem cut fragments were surveyed. Non-scraped creeping stems extended about 10 m in two months. The creeping stems were cut naturally in a flowing water-current (0.23 ± 0.01 m/s) , although the biomass was significantly greater under a stagnant water situation. Plants scraped to soil depth of 1 cm showed greater total biomass than that of plants scraped only on the soil surface. Creeping stem cut fragments having 2 nodes and 3 nodes with non-terminal buds regenerated well. Biomass of the creeping stem cut fragments of 2 nodes increased to more than 80% of that of 4-node fragments. Moreover, the total number of nodes increased almost equally to the total for a 4 node fragment. Results show that the creeping stems reproduced better in the case of scraping treatment, with cutting or damage, than in a non-scraping treatment.
