Abstract
River dike construction is usually accompanied by revegetation of bare soil using block sodding of a single turf species. With the aim of developing a technique for introducing several species simultaneously, we performed a 2-year experiment to clarify the effect of different methods of introduction (sowing vs transplanting) and with and without block sodding on the restoration of species representing semi-natural grasslands (Viola mandshurica W. Becker, Adenophora triphylla (Thunb.) A. DC. var. japonica (Regel) H. Hara, Cirsium oligophyllum (Franch. et Sav.) Matsum., and Sanguisorba officinalis L.). Transplanting treatment had higher rates of survival and flowering, and had greater plant height than sowing treatment. Although cover of germinated C. oligophyllum was relatively high in the second year irrespective of with or without block sodding, block sodding increased the survival rate of this species. Survival rate of V. mandshurica decreased markedly in the second year, probably due to the suppression by turf. A. triphylla did not germinate. Introducing floristic species in the joints of turf would be effective for species which grow taller than turf.
