Abstract
To demonstrate the seasonality of sprouting characteristics in Robinia pseudoacacia, we investigated sprout dynamics in Bibai, Hokkaido, northern Japan, over three growing seasons after the cutting of above-ground parts in May, June, or August 2004. Treatment season influenced growth in height for three consecutive growing seasons. Height growth tended to be higher for the May treatment and lower for the August treatment. The height growth for the same treatment season was consistently higher in Minami-Bibai stand than in Bannosawa stand. The number of sprouts decreased quickly and death of parent stumps, defined as the disappearance of living sprouts, was mainly observed between fall 2005 and spring 2007. Statistical analyses showed the dependency on treatment season for the sprout height and death of parent stumps. Death of parent stumps was also dependent on sprout height at the previous investigation. The volume of sprouts in 2007 was lowest in the August treatment. These results suggest that cutting the above-ground parts of R. pseudoacacia during high summer is effective for the removal of this alien species.
