Regrowth dynamics of common reed Phragmites australis after harvesting were investigated in a swampy section of Akigase-Park (35°51'N, 139°35'E). Shoots were harvested in June 2000 and July 2000. Observations were conducted from April 2001 to December 2001 particularly focusing on the reserve allocation to new to old rhizomes. Harvesting increased shoot density, however, decreased shoot diameter, shoot height and shoot biomass in the following season. Newly formed rhizomes were not affected by cutting event. Although 1-year-old rhizomes, produced in the treatment performed year, were decreased compared with a control stand. Older (3 to 5-years-old) rhizomes also reduced by consuming reserve materials for recovery from cutting damage.
These results imply that young reed communities are easily injured by accidental damages because of their small reservations. For wetland management, harvesting in June most efficiently suppress reed stands.