Abstract
We examined the effect of rhizome removal on the invasive perennial Rudbeckia laciniata L. in a laboratory experiment and field observations in Hakone, Kanagawa prefecture, Japan. To evaluate regeneration, randomly cross-sectioned fragments of R. laciniata rhizomes were cultivated in the laboratory for 60 days (25℃/15℃, 12h/12h). The probability of above-ground regeneration increased with the weight of the cultivated rhizome. The number of culms was monitored for three years in 14 plots where all R. laciniata within the plots were removed annually. The number of flowering culms deceased drastically. Nevertheless, culms with no flowers, which were thought to have originated from the seed bank, were abundant in the third year. These results suggest that R. laciniata can be eradicated by continuous rhizome removal. Based on these findings, schemes for eradicating R. laciniata were discussed.
