Formative and Decline Mechanism of Eelgrass Community Zostera japonica in Wetland Subjected to Influence of Hinterland Environmental Condition

Abstract

Field observations on Zostera japonica habitat and transplanting experiment were conducted in order to obtain scientific knowledge on preservation and restoration of eelgrass beds. The observed seasonal changes in density of Z. japonica were large, and the rhizome biomass had drastically decreased from 0.40g/100cm2 to as little as 0.05g/100cm2 in a year. The transplanted Z. japonica increased their shoots by 30 times, however, most of the shoots had disappeared in 8 months. The rapid disappearance appears to be due to rise in the sea bed level during the period. It is suggested that sediment inflow from the hinterland must be controlled as well as the possibility of propagation of species be enhanced not only by rhizome extension but by seedling in order to keep Z. japonica community in the site.